Tuesday, December 29, 2009

Dead salmon CAN think! Or an argument for multiple comparison corrections

Just over five years ago, a New Square fish store owner and his employee claimed to have had a talking carp:

Mr. Rosen said that when he approached the fish he heard it uttering warnings and commands in Hebrew.

"It said `Tzaruch shemirah' and `Hasof bah,' " he said, "which essentially means that everyone needs to account for themselves because the end is near."

The fish commanded Mr. Rosen to pray and to study the Torah and identified itself as the soul of a local Hasidic man who died last year, childless. The man often bought carp at the shop for the Sabbath meals of poorer village residents.

Few believed them, though many jokes were made such as the gefillte fish manufacturer who considered taking on the slogan "Our fish speaks for itself".

Now neuroscientists have documented brain activity, not just in a live carp of the story, but in a dead salmon, in the paper, Neural correlates of interspecies perspective taking in the post-mortem Atlantic Salmon: An argument for multiple comparisons correction. As they put it in their Methods section:

Subject. One mature Atlantic Salmon (Salmo salar) participated in the fMRI study. The salmon was approximately 18 inches long, weighed 3.8 lbs, and was not alive at the time of scanning.

Task. The task administered to the salmon involved completing an open-ended mentalizing task. The salmon was shown a series of photographs depicting human individuals in social situations with a specified emotional valence. The salmon was asked to determine what emotion the individual in the photo must have been experiencing.

Just picture the scene for a moment. I would love to talk to the research assistant who had to talk to the salmon and show it pictures. What kind of "mentalizing" does a person have while speaking to a dead fish?

The conclusion:

Can we conclude from this data that the salmon is engaging in the perspective-taking task? Certainly not. What we can determine is that random noise in the EPI timeseries may yield spurious results if multiple comparisons are not controlled for. Adaptive methods for controlling the false discovery rate and familywise error rate are excellent options and are widely available in all major fMRI analysis packages. We argue that relying on standard statistical thresholds (p < 0.001) and low minimum cluster sizes (k > 8) is an ineffective control for multiple comparisons. We further argue that the vast majority of fMRI studies should be utilizing multiple comparisons correction as standard practice in the computation of their statistics.

The study was also covered by Science News in an article on lack of replicability of fMRI experiments. The Science News story includes a quote that is a good idea for everyone, whether or not they do fMRI experiments: “Statistics should support common sense. If the math is so complicated that you don’t understand it, do something else.”

When this study wins the Ignobel Prize, you can say you saw that prediction here first.

Tuesday, December 15, 2009

Is it possible to restore the norm of no premarital sex?

News today about gaps in sex education has a fantastically clear quote about the goals of conservative policy towards sex education:

"I don't think we'll be able to overcome this problem unless we restore the social norm of not having sex and not getting pregnant before marriage," said Peter Sprigg, senior fellow for policy studies at the Family Research Council.

Social conservatives do not generally support research about social norms about sexuality, so we do not know as much about sexual norms as we would otherwise. According to the earliest representative studies by sociologist Ira Reiss, the attitudes to allow what Ira Reiss called "permissiveness with affection" started shifting in the 1940s, and the shift was well underway by 1950 and definitely by 1960 when Ira Reiss wrote Premarital Sex in America (the link goes to the actual book). It seems unlikely that such a long-standing attitude shift could be easily reversed. By now, it is the standard that even many Evangelicals follow. If they marry right after college, it's possible they may abstain, but if they marry later, it's very unlikely, and many do marry later.

I would argue that permissiveness with affection is not a policy issue. No public health problems result from premarital sex within long-term committed monogamous relationships. Disease spread is self-limiting. Still, if changing that social norm is a worthy public policy goal, they have to look to more recent trends first.

One norm that has changed more recently are attitudes towards what Reiss calls "permissiveness without affection:" just as AIDS was emerging in the early 1980s, academics were declaring this to be the new norm. From the poll data in the link (which I would guess is an incomplete picture of the available data), it looks like endorsement of the norm may have declined with AIDS/HIV, and has begun to reemerge to some extent and even become part of public discourse, with everyone having heard of the idea of "Friends with Benefits". Unlike permissiveness with affection, there is some degree of a public health justification due to the herpes and HPV risks.

But that means you have to acknowledge that that nearly all Americans have premarital sex, and teach real sex education to protect them.

And then you have to think of a policy that can change social norms. Incidentally, changing social norms would seem to be totally inconsistent with a limited government of the sort that Conservatives say they want.

Open letter to Senator Lieberman

Dear Senator Lieberman,

As a Harvard Health Policy PhD and Jew, I am sad to hear that you are weakening health care reform.

As a Health Policy PhD, I refer you to my professors in the Harvard Health Policy program, who say the original Senate health care bill is the best available solution.

As a Jew, I remind you that the Rabbinic Sages teach us not to be like the men of Sodom who would say שלי שלי ושלך שלך "What is mine is mine and what is yours is yours." The Sages taught that justifying inequality is not just negligence, but actually evil.

The present US system could be a model for Sodom: discounted prices to the rich/insured/healthy and inflated prices to the poor/sick/uninsured. Any solution that perpetuates inequalities between privileged/healthy and poor/sick perpetuates the health care system of Sodom.

Strong health care reform is a policy and Jewish imperative.

Janet Rosenbaum, Ph.D. Health Policy, Harvard 2008
Johns Hopkins Bloomberg School of Public Health

Monday, December 14, 2009

Quantifying and qualifying casual sex

A recent paper compares measure of "psychological wellbeing" between people whose most recent relationship was casual versus serious, and finds no difference. The paper motivates itself by the speculation in public discourse and the teachings of abstinence-only sex education that casual sex is harmful.

The qualitative research on the subject of casual sex seems pretty clear that, to the extent that they exist, the harms of casual sex would be unlikely to be found on a psychometric measure. Kathleen Bogle's qualitative study found that college-aged women feel frustrated and sometimes their feelings are hurt by differing expectations, which is also consistent with what Laura Sessions-Stepp reports in her journalistic book. I haven't ever seen anyone suggest higher rates of mental illness among people who have casual sex. It seems highly unlikely that casual sex poses a public mental health problem. (Casual sex does likely increase the total lifetime number of sex partners, so increases STD risk, but that's not the main issue here.)

The lack of a quantitative measure for romantic frustration doesn't make it unimportant. Just as quantitative research finds that married men seem to be in better physical and mental health than unmarried, but no difference for women, doesn't diminish the importance of the desire of many unmarried women to be in committed relationships. Likewise, quantitative research finds that people with children are more unhappy than people without, and yet there is an entire medical subfield dedicated to making people unhappy by helping them have children. (Likewise, my understanding is that US medical doctors stopped performing sex reassignment surgery after quantitative studies found no improvement after surgery, and yet qualitatively transgendered people who choose surgery report an improvement.)

Intangibles are important. Keep those qualitative studies coming.

Sunday, November 29, 2009

Abstinence-only music videos.

Washington City Paper features Top Five Abstinence Only music videos as well as a music video about the Christian Side Hug.

The potentially most negative video for STD prevention, "Ain't NO safe way" shows a couple in a drive-through. The man says no on the grounds that sex is dangerous. The woman holds up a condom saying vacantly as if hypnotized, "If they give these out in school, it must be safe." Her eyes widen further, unblinking, crazed, as she intones, "Don't worry. It's SAFE." "Safe" echoes in the background. Heavy metal music starts with "Wages of Sin = DEATH" on TV screens blinking in the background. (The boy says no, and gets out of the car, and the girl drives away disappointed.)

All five of these fall into the shaming language of "lose" and "take" virginity, and one girl even telling her friend "you should be ashamed" for having sex, as well as the ethnic stereotypes: many feature black women saying no to black men, and none feature Asians (who are disproportionately represented among virginity pledgers, but the stereotype is that they have no problem saying no.) Nor do they include black men turning down women.

Tuesday, November 24, 2009

Twilight books romanticize domestic violence?

The Twilight book series has been thought of as promoting abstinence, so I've followed it somewhat because of my work. I found it interesting to read this post, which goes through the checklist from the National Domestic Violence hotline for Bella and Edward's relationship, and finds 15 signs that their relationship is abusive. Fifteen! I have only read articles about the books and movies, not read the books or seen the movies myself, so I am frankly surprised to hear that Edward throws Bella through a glass table. But even the other signs, like repeated statements of jealousy, abandoning her in a dangerous place, threatening suicide. . . This is supposed to be romantic? Religious groups can't possibly approve of these books, abstinence message or no.

Also: the view from a school librarian (and member of my Cambridge synagogue).

Thursday, October 8, 2009

Hormonal contraception makes women less attractive and choose worse partners, says review paper

A few months ago, I said that hormonal contraception (the pill, Depo, etc.) messes up women's choice of mates because of results we knew that women choose differently and asked whether that's responsible for higher divorces in those couples. We still don't know that information, whether divorce is more likely among women who chose their partners using hormonal contraception.

But a review paper has come out solidifying that finding that women choose partners differently on hormonal contraception than off and adding that women are less attractive while they're taking it because it suppresses ovulation (during which women are more attractive to men).

That's another reason to add to the book that just came out saying that women ought to consider other methods besides the pill.

Hormonal contraception is a standard, and evidence probably won't change that, but there are other equally reliable methods of pregnancy prevention such as intrauterine contraception (IUC) that currently have miniscule proportions of women using them. I wonder whether we'll see even a slight shift.

(Conflict of interest disclosure: I have a very nice pen given to me by the company that makes an IUC device that I happen to have used this morning, but really that's not why I wrote that. This is just the first time I've ever had one of those legendary conflicts of interest.)

Monday, October 5, 2009

Political compromises on sex ed

I'm an ardent moderate, but I find the administration's compromises counterproductive. Obviously the stimulus compromise didn't work: the bill was watered down, and virtually no Republicans voted for it anyhow.

If the health bill passes, the sex education situation will go to $50 million for abstinence-only education, $50 million for evidence-based comprehensive sex education, and $25 million for experimental comprehensive sex education. That's not compromise. That's going also against popular opinion: 52% of even politically "very conservative" parents favor teaching birth control in schools, and 89% of the general population of parents. Just as most of the public and most physicians favor the public option, but that doesn't make it into policy either.

More importantly, it's going agsinst the findings of the Congressionally-mandated study finding that abstinence-only sex education doesn't work.

They're not listening to either the public or the researchers they hired.

Friday, October 2, 2009

Why the placebo effect is an effect

There was an interesting article in Wired recently that spoke about the placebo effect getting stronger: that the pre-post difference from a placebo drug is greater than it was a decade or two ago and that it differs between countries. That is, if you are looking at antidepressants and your outcome measure is a score on the Beck Depression Inventory that measures how depressed someone is, the score before the drug minus the score after the drug is different now than it was 10 years ago.

One criticism of the article is that the placebo effect cannot be considered an effect unless it is compared with another experimental condition. Since drug trials don't include both patients who receive a placebo and patients who receive nothing, there is no such thing as a placebo effect unless we know what the pre-post difference would have been in the absence of the placebo. Without a nothing arm to compare with, the writer contends that the pre-post difference in the placebo arm of a trial is just by definition the background noise in the trial.

I think that he's making a semantic point because a true placebo effect is impossible to measure.

To break the problem down further:

We do not know what the pre-post difference in a nothing arm of a trial would be. In some trials and for some diseases, there would be spontaneous improvement in the patient's condition: in that case, the pre-post difference in the placebo might just be that spontaneous improvement that would have happened if nothing were done.

In some trials and for some diseases, there would not be much change in the patient's condition, so the nothing arm would have no difference: in that case, the pre-post difference in the placebo arm would represent an "effect" and we could say that we have a placebo effect.

The question is which diseases have spontaneous improvement and which don't. There are three ways I can think of to figure this out.

1. A randomized clinical trial with patients that actually have some disease in which half the patients get a sugar pill and half the patients get nothing. No human subjects board would authorize this trial. Second, the study would not measure what we want it to. Ethically patients have to be told that the two possibilities are sugar pill and nothing. The Wired article contends that the placebo "effect" is based on a patient's prior beliefs about a drug's effectiveness, so it's specific to the drug, rather than being just the effect of a plain sugar pill.

2. The placebo effect could in theory be measured with matching, were there any subjects to match them to. The placebo pre-post difference can be defined in two ways: the pre-post difference of the sugar pill plus the pre-post difference of enrolling in the trial, or just the pre-post difference of the sugar pill alone. I would say it's the former. In that case, where we want to measure the effect of enrolling in a trial and taking a sugar pill, we could match normal patients with placebo patients based on their records and compare their pre-post differences. Except for the fact that medical records of normal patients with a disease are there because the patients are getting some treatment from their doctors. So there's no group to compare the placebo patients to.

3. The one remaining possibility is for each drug trial to divide their control group into two unequal groups: one receiving a sugar pill would be the larger group and one being put on a waiting list for the drug would be a smaller group. The problem is that placebos serve two purposes: one is for the statistical purpose and one is to keep the participants in the study and encourage them against taking other treatments. Depending on the condition, a control participant put on a waiting list might leave the trial or take another treatment in addition to the waiting list. So you might lose a good portion of the nothing arm of the trial.

Given the impossibility of rigorous measurement of what would happen under no treatment, the best we can do is guess which are the diseases where symptoms spontaneously resolve and which are the diseases where they don't. And that's what we already do when we talk about a placebo effect. We compare the pre-post difference in the placebo arm of a trial with our beliefs about what the pre-post difference would be with no treatment. In that sense, the placebo effect is really an effect. It's just imprecise.

Further, it's reasonable to assume that whatever the pre-post difference under nothing is, it's not going to change with time in any systematic way. If we could put all the placebo arms of, say, antidepressant trials together and find a trend with time, that's not sampling error. And that's exactly what the Wired article is talking about.

Statisticians protest at G-20 conference for safer data mining

Dating miners protest alongside United Steelworkers at the G-20 conference. My favorites: "Repeal Power Laws," "Our Sets. Our Axiom of Choice."

They even got John Oliver from the Daily Show to join in. I can't read the sign he is holding.

Thursday, October 1, 2009

Booty Call journal article

Journal of Sex Research published an article about "The 'Booty Call': A Compromise Between Men's and Women's Ideal Mating Strategies." It is not even slightly representative, just some Texas undergraduates, but its conclusions are similar to those of the book Hooking Up that I reviewed here. Hooking Up was a qualitative study of two undergraduate populations that followed subjects in college and a year or two after graduation.

Here are its conclusions:

With regards to accepting versus rejecting booty call partners, physical attractiveness was considered the most important criteria by both genders. Fourth, whereas men tended to cite other reasons related to sexual access, women tended to cite reasons related to friendship, compatibility, and personality. Fifth, for booty calls that do not progress into long-term relationships, both genders attribute the lack of progression to the man's not wanting a long-term relationship. Taken together, our results suggest that, although booty calls are mostly a sexual relationship whereby physical attractiveness is important, there are elements in which booty calls differ from other casual sexual relationships, such as one-night stands or hookups. In addition, whereas men tend to favor the sexual aspects of booty calls, women tend to favor other, more long-term oriented considerations. These findings are consistent with our overall hypothesis that the booty call may represent a compromise between the short-term, sexual nature of men's ideal relationships and the long-term, commitment ideally favored by women.

As with Hooking Up, the women surveyed have long-term ideas in mind but are willing to settle for short-term. Unlike Hooking Up, none of the women discuss an initial stage of experimentation with hooking up when they did not want a long-term relationship and just wanted to experiment with short-term. Perhaps the survey did not ask them about that.

Wednesday, September 30, 2009

An open letter to Senator Orrin Hatch

Dear Senator Hatch,

I am the author of two of the approximately ten published papers about the sexual behavior of virginity pledgers. I found that virginity pledgers may lie about their sexual pasts and that they are less likely to use condoms when they do have sex.

Thank you for thinking of my research when you added an amendment for $50 million of Abstinence-Only Sex Education funds to the health reform bill. If the federal government does not fund abstinence education, my research into the sexual behavior of virginity pledgers and evangelical adolescents would lack policy relevance, so I'm truly grateful for this opportunity.

Nonetheless, I have to turn down this generous offer. I have a surfeit of other research topics, and I've moved on with my research. Even most abstinence proponents have moved on with their efforts. Every abstinence proponent I've spoken with, including leading Southern Baptists, seem to accept that their approach to sex education needs to be reworked. The evangelical media's reaction to my most recent paper finding virginity pledges do not work was mild (in the case of Focus on the Family Radio and the Baptist Press) and even favorable (in the case of Christianity Today).

More importantly, as you know, the case against Abstinence-Only Sex Education was definitively made by the Congressionally-mandated evaluation of the program published in 2007 by Mathematica Policy Research.

I consider that perhaps you made this amendment for ironic effect: if your amendment stays in the bill, the Democrats who favor health reform will have to vote for your abstinence funding. If so, your point was made, and I have laughed heartily at the irony. Now you can remove it.

Best of luck in your continued efforts.


Janet Rosenbaum, PhD

Thursday, September 24, 2009

Baptists debate abstinence ... from alcohol

Apparently there's a debate within the various streams of Baptists about whether abstinence from alcohol is still a necessary part of their religion. The anti-abstinence say that alcohol abstinence is a historical remanent of the Temperance/Prohibition Movement 100 years ago and the pro-abstinence say that it's important to draw a firm line so that no one is tempted to get drunk.

I wonder whether they'll be having a similar debate in 100 years about some aspects of sexual abstinence. That's kind-of a naive question.

Wednesday, September 23, 2009

Bumper sticker of the day

"DON'T DRINK AND PARK: Accidents cause people"

I saw this bumpersticker last night while driving home from a Harvard interviewing workshop. It was just text. Now that I google the phrase, I find some depictions that definitely aren't the classical meaning of "parking."

Sunday, September 20, 2009

Condom ads

Condom ads around the world.

My favorites: 1970s style US porn, condoms dancing Bollywood style, and Kenyan Trust-brand condoms covering an umbrella. According to youtube, the Kenyan ad was banned.

Thursday, September 17, 2009

Women's recurrent need for self-defense

We had three related stories in the news this week:

  • India's women-only train cars, necessary due to extensive harassment and recent increase of women working outside the home;
  • the murder of a Yale graduate student by a co-worker, which New Haven police emphasize is an issue of workplace violence, not domestic or street violence;
  • a Hopkins undergraduate's accidental killing of an intruder using a samurai sword.

I'm glad that the New Haven police again emphasize that the primary risk to women is the people they know rather than strangers on the street. People have an easier time thinking about self-defense from strangers. Strangers are the least likely attackers, but the line between an attack and a non-attack is brighter, which may be why the Hopkins undergrad was able to take such decisive action; it's obvious that the intruder did not belong there and had already committed a crime. In the case of an acquaintance, it's harder to find the line between minor conflict and potential violence.

According to the National Crime Victimization NCVS survey, 2 million people are the victim of workplace violence on average each year, with homicide being only the extreme of the scale of violence. Workplace violence is the second highest cause of workplace death for women. I wonder how these figures compare with other countries, and what proportion are due to guns, or whether the US is somehow more violent due to inequalities.

Hearing these stories, I've been feeling grateful that my mother took me to a multi-week self-defense class when I was a young adolescent. The class was run by a Chicago organization Chimera that emphasized response possible at each level of escalation, and the realistic responses that women can make to each level appropriate to the situation.

Judging from the murderer's injuries --- "bruises and abrasions on his arms, a mark under his eye, a scratch on his right ear, and a bruise or deep scratch to his chest" --- the victim employed the most common ineffective self-defense tactics. If someone is intent on hurting a woman, the only way for her to stop them is to disable them somehow. Arms and chest are strong, especially on a man, but we learned that even strong people have weak parts and effective self-defense includes poking eyes, striking nose with the palm, using keys as weapons, stomping on tiny foot bones, and dislocating knees.

Of course it's impossible to know what really happened, and everything is much easier said than done especially given the judgement call necessary to realize whether one is really in danger. This attack reminds me to take a self-defense refresher course and makes me thankful that I learned self-defense from an active feminist group as an adolescent so that it became subconscious, reflexive knowledge. I hope that I never find out how well I learned this material.

May her family and fiance be comforted in their loss.

Tuesday, September 15, 2009

Health reform letter to the editor

I wrote a letter to the editor of a Baltimore Jewish publication. It sounds like they will not publish it, so here it is:

Dear Editor,

As a graduate of both Shaarei Tzedek Medical Center's Schlesinger Institute Medical Ethics program in Jerusalem and Harvard's Ph.D. program in Health Policy, I was excited to see an article on the health care reform debate in this month's WWW because there are certainly Jewish perspectives on the issue. I read it through eagerly but was disappointed that the piece turned out to be boiler-plate rhetoric with a tenuous connection to facts.

For instance, the author says "there is no one in the country who is really uninsured" because everyone can just go to the emergency room and hospitals get reimbursed for that care. This system actually jeopardizes the health of both uninsured patients and hospitals: patients delay seeking care until an emergency, and hospitals go out of business because reimbursement does not directly cover uncompensated care but rather comes indirectly. For instance, a hospital which gives more care to uninsured might make 5% more on hernia operations; unsurprisingly, books do not always balance.

Other claims were irrelevant distractions, such as about end of life care. Government programs already cover the most vulnerable patients such as the elderly, certain terminally ill patients, wounded military members, and veterans through the government insurance program Medicare and government health care provided at Veteran's Affairs (VA) and military hospitals. End of life care is clearly not an issue with these current programs.

Far from ending life, government-provided health care at VA and military hospitals has saved lives in this war that would have been lost in the nation's 9 previous wars. These lives were saved due to comparative effectiveness research, the field funded in the stimulus package for $1 billion that was unfairly maligned by conservative commentators as leading to "death panels." In the 1990-91 Persian Gulf War, 24% of injured soldiers died from their wounds --- the same proportion as in Vietnam and a bit higher than the 19% in the 1898 Spanish-American War and 21% in World War I --- so technology does not seem to be the key factor in reducing wound fatality. In the current wars in Iraq and Afghanistan, only 10% of injured soldiers died from their wounds, largely because of improvements in care delivery (Gawande NEJM 2004). Health services researchers discovered that battlefield stabilization of injured soldiers and rapid movement to US military hospitals reduced wound lethality. The resulting "government interference in the doctor-patient relationship" literally saved twice as many lives as would have been saved by the old system in which battlefield surgeons held onto patients as long as possible rather than moving them through the system.

The Rabbis of the Talmud teach us not to be like the men of Sodom who would say "What is mine is mine and what is yours is yours." Many of us are lucky enough to have secure jobs with stable health insurance, but even giving tzedakah [charity] to pay for the health care of the uninsured is not enough to help the uninsured. Hospitals charge much higher prices to uninsured individuals, while insurance companies have leverage to insist on lower fees. If Sodom had a modern health care system, they could model it on this situation: discounted prices to the rich (health insurance companies) and inflated prices to the poor. Any solution that perpetuates this inequality in pricing between privileged and poor perpetuates the health care system of Sodom.

Prevention is the best medicine, of course. May we all have a new year of health so that we do not personally need the health care system.

Janet Rosenbaum, PhD

Sunday, September 13, 2009

Overly conservative statistics and yogurt

Are overly conservative statistics preventing the adoption of low-risk potentially beneficial health care?

It seems like probiotics are being talked about everywhere. We know that "good bacteria" are vital in many cases: babies delivered vaginally versus via c-section, for instance, have better immune function due in part to the bacterial colonization they get on their way out. (Of course, if the mother has chlamydia or other bad bacteria, the babies can get colonized by those too and develop eye infections.) Now that flu is in the air, people are citing studies that certain probiotics can help prevent and shorten flu infection. Probiotics are inexpensive and reasonably harmless: the worst side-effects I've seen attributed to them are the same as placebos such as mild GI distress. Probiotics seem like the canonical case of "can't hurt, could help." Kefir and yogurt are tasty, too.

Recently I ran across an immunologist's summary of the report of a 2005 Yale medical school conference about probiotics, mentioning among other things that probiotics might be able to help a disease a friend has. The hypothesized mechanism makes sense that it would help, so I looked at the Cochrane reviews, a formalized method for summarizing medical literature, and they say there's no evidence. The only studies were so hopelessly small, though, that there's no way to know at this point. So I looked up "probiotics" in Cochrane and got these results showing that there are about 82 abstracts relevant to probiotics. Of the 10 or so that I read, the only ones where Cochrane said there was conclusive evidence was for acute infectious diarrhea.

An interesting case: pediatric antibiotic-induced diarrhea. They noted the effects of missing data: if all the study drop-outs were treatment failure, which seems unlikely, the treatment doesn't work. Immediately after that, they acknowledge that there is almost no downside to the treatment: "Probiotics were generally well tolerated and side effects occurred infrequently." and yet they conclude, "Although current data are promising, there is insufficient evidence to routinely recommend the use of probiotics for the prevention of pediatric AAD."

In other words, there's no downside to using probiotics, but because the overly conservative statistical analysis that counts all treatment drop-outs as failures finds that they don't work, they can't recommend them. There are many reasons why subjects might have dropped out of this study, primarily boiling down to the studies being almost certainly poorly funded and unable to adequately compensate busy parents of sick children needing to catch up on their lives after their children recovered. That caution in counting drop-outs as failures is reasonable in some cases: for instance, if the proposed treatment is invasive or risky. Or in the case of the female condom hearings the commercial sex workers who dropped out of the study could have been the ones for whom the condoms didn't work as well. In this case of probiotics, they're virtually risk free and there's a good reason why parents may have dropped out of the study.

In medical statistics (biostatistics), the methods most commonly used are straight out of a textbook, rules of thumb that apply in general. Obviously context counts and we should be more conservative when there's a risk and less conservative when there's little risk. Biostatistics is not my primary area, but I have helped doctors out with the occasional clinical trial, using the textbook methods because that's what they wanted. There are many better methods that could be used to analyze this data, such as decision theory that accounts for risks, or missing data methods that model the potential outcomes of the study drop-outs. Biostatisticians have no malpractice risks, so there's no reason they couldn't be less conservative in their choice of data analysis methods to account for risk. Somehow the conservatism that US doctors practice under has spread to biostatisticians, though. Until statistics becomes less conservative in their analysis methods, patients may end up missing out on low-risk treatments still being studied.

Sunday, September 6, 2009

David Kessler's The End of Overeating

I remember when David Kessler became head of the FDA when I was in middle school. As an MD with a JD, he was a model for combining policy interests with scientific knowledge of health. In my middle school judgement, I found what he said incredibly sensible and just plain smart, and I decided that I should also get an MD/JD so I could grow up to be David Kessler.

Middle school judgements are sometimes exaggerated, but his book The End of Overeating does not disappoint in terms of the breadth of information that it tries to integrate. Kessler combines both human and animal research, frank and sometimes shocking conversations with food consultants revealing the secrets of increasing consumption (e.g., soft drink companies attempting to induce people to drink less water), and a food travelogue to create a compelling story to explain American obesity. For instance, Kessler discusses methods of food manufacture that causes processed restaurant chain food to break down the protein structure of meat and inject marinade so that it can be consumed more quickly than standard meat.

One of his central points is that sugar, salt, and fat combine to make food compelling ("hyperpalatable"), but he treats these elements as if they are interchangeable, but all hyperpalatable foods that he gives as examples have elements with a high glycemic index (breading, sugar, etc.) and the nutrition literature recognizes a distinction between fat and sugar. For instance, rats will overeat on pure sugar, pure fat, and sugar/fat mixtures, but only fat or sugar/fat mixtures increases weight but rats don't gain weight on sugar (one area in which they're clearly different from people --- witness the Snackwells effect which he mentions as well). Rats have few problems discontinuing fat, but discontinuation from sugar causes withdrawal symptoms similar to opioid withdrawal. (Avena NM, Rada P, Hoebel BG. Sugar and fat bingeing have notable differences in addictive-like behavior. J Nutr. 2009 Mar;139(3):623-8. Epub 2009 Jan 28.)

His theory and examples are also disjointed from each other. To bolster his claim that sugar alone is not enough to create hyperpalatability, he describes experiments in which people find skim milk with sugar added unpalatable but really like cream with sugar added, but then he contradicts this theory by describing his own struggles that lead him to eat an entire box of Snackwells fat-free cookies in a short period.

A theory based on macronutrients has extreme limits. While he does talk about flavor with food consultants, he doesn't incorporate flavor into his theory; obviously flavor is complicated. In a few places he says that obviously sugar in the absence of fat isn't a problem because people aren't eating sugar straight out of the bag, not considering that it's not exactly common to see people drinking oil out of the bottle or eating sticks of butter. Flavor is of course the important moderator: people will eat large numbers of meringues, jelly beans, angel food cake, Snackwell cookies, and all sorts of high calorie fat free foods, just as they will eat bacon (and I can't think of any other examples of fatty foods that derive nearly 100% of their calories from fat, to be comparable to jelly beans). An interesting counterpoint would be if he performed experiments in which he tested consumption of food in the absence of flavor, such by wearing noseplugs, as Seth Roberts has experimented with on a small scale.

He makes some strange claims about people historically eating low-fat meat and cites USDA data that people eat more fat than ever before, though other USDA data says that fat consumption has decreased since the 1970s and only sugar consumption has increased.

The book's chapters were short and did not tie together well, so his argument came off as more simplistic and repetitive than if he had written longer chapters that would have necessarily tied his argument together well. Even the short chapters sometimes ended abruptly. For instance, he has a chapter about Cinnabon, the 730 calorie pastry (sidenote: I remember from the only time I had a Cinnabon sometime in middle school that it had 500 calories and being horrified; I decided to check that calorie count again, and in fact now it's 730. Now that 500 calorie cookies are common, Cinnabons had to become 50% larger than before!) He interviews the creator of the Cinnabon and reveals that she had second thoughts about her creation, echoing Cookie Monster's refrain that "cookies are a sometimes food", and that she had created the Cinnabon to be a treat. He adds in a tantalizing last detail that she used to suffer from eating disorders and was unable to distinguish hunger from other needs, but then he ends the chapter abruptly without relating her eating disorder to her second thoughts about having created the Cinnabon.

The chapters about how to resist food are not new and have been covered better elsewhere such as in Brian Wansink's Mindless Eating as well as of course in the literature.

The book does add to the plausible explanations for the rise of obesity in the US, and it's well worth taking an afternoon to read this book. The quotes from food consultants about how to create "irresistible" and multi-layered "eating experiences" ("eatertainment") were especially revealing of the great deal of effort food companies have exerted to produce American obesity.

Thursday, September 3, 2009

R Statistics flash mob for Tuesday

Wow, this is too funny.

> From: The R Flashmob Project
>Subject: R Flashmob #2
>You are invited to take part in R Flashmob, the project that makes the
>world a better place by posting helpful questions and answers about the
>R statistical language to the programmer’s Q & A site stackoverflow.com
>Please forward this to other people you know who might like to join.
>Q. Why would I want to join an inexplicable R mob?
>A. Tons of other people are doing it.
>Q. Why else?
>A. Stackoverflow was built specifically for handling programming questions.
>It’s a better mousetrap. It offers search (and is well indexed by search engines),
>tagging, voting, the ability to choose the “best” answer to a question, and the ability to
>edit questions and answers as technology progresses. It has a karma system to
>reward people who are happy to help and discourage MLJs (mailing list jerks).
>Q. Do the organizers of this MOB have any commercial interest in stackoverflow?
A. None at all. We’re just convinced it is the best way to help and promote R. All
>the content submitted to stackoverflow is protected by a Creative Commons
>CC-Wiki License, meaning anyone is free to copy, distribute, transmit, and
>remix the information on stackoverflow. All the content on stackoverflow is
>regularly made available for download by the public.
>Location: stackoverflow.com
>Start Date: Tuesday, September 8th, 2009
>Start Time:
>10:04 AM – US Pacific
>11:04 AM – US Mountiain
>12:04 PM – US Central
>1:04 PM – US Eastern
>6:04 PM – UK
>7:04 PM – Continental W. Europe
>5:04 AM (Weds) – New Zealand (birthplace of R)
>Duration: 50 minutes
>(1) At some point during the day on September 8th, synchronize your watch to
>(2) The mob should form at precisely 4 minutes past the hour and not beforehand.
>(3) At 4 minutes past the hour, you should arrive at stackoverflow.com, log in,
>and post 3 R questions. Be sure to tag the questions “R”. See the posting
>guidelines at http://stackoverflow.com/faq to understand what makes a good
>(4) Follow R Flashmob updates at http://twitter.com/rstatsmob
>(5) Post twitter messages tagged #rstats and #rstatsmob during the mob,
>providing links to your questions.
>(6) During the R MOB, you can chat with other participants on the #R channel
>on IRC (freenode). To do this, install the Chatzilla extension on Firefox.
>Click “freenode” on the main screen. Then type /join #R in the field at the
>bottom of the screen. Then chat.
>(7) If you finish posting your three questions within the 50 minutes, stick
> around to answer questions and give “up votes” to good questions and answers.
>(8) IMPORTANT: After posting, sign the R Flashmob guestbook at
>(9) Return to what you would otherwise have been doing. Await
>instructions for R MOB #3.

Off-topic: Gluten-free blogger dies

David Marc Fischer, the 46 year old author of the most useful gluten-free blog Gluten-free NYC died last month on August 6 apparently from leukemia. His blog was distinctive for giving gluten-free medical and policy news, rather than focussing exclusively on food food food. Also, he sounded like a nice guy who I'd wanted to meet. May his family be comforted in their loss.

Tuesday, September 1, 2009

Texas wins a prize for high teen births

Texas papers such as the Dallas Morning News and Houston Chronicle are the only papers in the country reporting the results for Texas of a Child Trends teen pregnancy study that is supposed to come out tomorrow. I can only assume that being allowed to break a story early is a reward for their cities' stellar performances: Dallas has the highest proportion of repeat teen births and Houston leads in births under age 15. Of course there is nothing funny about any of this.

The majority are to Latinos. About 95% of Texas schools provide no information other than abstinence to students, a policy supported by white-majority churches such as the Southern Baptist Conference. The lack of information may disproportionately impact Latinos, however, who may come from cultures where sex and birth control are not discussed and may have less access to the internet or other sources of information.

Friday, August 28, 2009

"Treasure or target?" Quiz

Feministe blog has the review of an abstinence-only curriculum that includes a quiz called "are you a treasure or a target?" They have 6 questions that are interesting situations. For instance, one question asks what to wear now that micro minis are fashionable: a micro mini, cargo shorts, or a skirt a few inches above the knee. And they label the options in that order of preference, which seems pretty arbitrary to me.

Social scientists conduct large long time frame studies to find the optimal answers, so I can't say that I know what the "right" answer is to any of these questions. Amusing to think about conducting a study where some women are randomized to wear different clothing styles to see what the outcome is. Actually that would be a fantastic trial. Five conditions:

1. Covering everything except hands and feet, though maybe not hair?, a la Little Mosque on the Prairie character Rayyan Hamoudi whose style is so admired there are blogs that try to figure out where to find her clothes.

2. Covering knee to elbow, more or less, a la Mayim Biyalik or the Hot Chani style. As far as I can tell, this is roughly the Mormon guidelines as well as the guidelines for those who consider themselves to practice "Authentic Judaism".

3. Regular tomboy style: jeans, cargo shorts, loose t-shirt.

4. Mainstream Evangelical Christian style, so a bit more conservative than normal: no cleavage, no midriff, small number of inches above knee.

5. Standard US fashion style. Whatever is featured by H&M, Zara, etc.

I'd love to see the experiment that would randomize people to different styles to see whether they acted in a way that fit their clothing. Separately, I wonder if you randomized people to dress straight out like a member of a religion (e.g., non-Muslims actually wearing a hijab or non-Mormons actually wearing the secret undergarment), some people would end converting to the religion. Such an experiment would answer a really fundamental question in social science about to what extent behavior is determined by internal cues or social cues. It would also be enormously un-PC.

But that's neither here nor there. Quizzes are arbitrary and we have no way of knowing what the "right" answer in these circumstances.

The general idea of choosing dates who are interested in long-term relationships seems like a valid concern, as shown by Bogle's Hooking Up book and Laura Sessions Stepp's book that late adolescent women who choose dates without knowing (or in denial of) their dates' relationship objectives often end up disappointed and frustrated by a lack of long-term relationships.

Of course asking about claimed objectives isn't enough. I went on a date with a gentleman who professed serious interest in a long-term relationship and eventually marriage, and he seemed considerate and sensitive. On our third date, I asked him about his sexual history (one of the privileges of my profession). He told me that in addition to his 5 relationships that lasted more than a year (in some cases much longer), he had gone out on 3-5 dates with 20-35 women whom he had sex with and he stressed earnestly that at the time he had sex with them he had intended to go out with them again. He trailed off.

I have no idea what gives him only a 12.5-20.0% chance of deciding to initiate a year-long relationship with a woman he has sex with, and perhaps he doesn't either. Going purely on the statistics, this guy seems like an unlikely bet, which honestly didn't surprise me: something about him had led me to keep my distance. Giving the benefit of the doubt, I'm guessing this is what the quiz is trying to get women to be aware of, and that seems reasonable also from a third wave feminist perspective: knowing the prior probabilities can't hurt; if a woman doesn't care for a long-term relationship and just wants a sexual relationship, that's her choice as well.

Thursday, August 27, 2009

Review of You're Teaching My Child WHAT?

Dr. Miriam Grossman, formerly Anonymous MD, has written another book, entitled You're Teaching My Child WHAT? A Physician Exposes the Lies of Sex Education and How They Harm Your Child. My thoughts about this book are almost identical to my review of her earlier book, perhaps because the books have nearly identical tone and content. As I stated in that review, "This evident alarmism --- PC is so insidious that the author must remain anonymous or risk Birkenstocks being thrown through her front windows --- that pervades the book may cause parents and aggrieved social conservatives to pick up the book, but it does no good for Dr. Anonymous's arguments and alienates people who might otherwise agree with her." As in her previous book, Dr. Grossman makes valid points in the most invalid ways, alleging cover-ups and duplicity and a single radical academic agenda when none exists.

I have three responses specific to this book.

First, Dr. Grossman refers multiple times to a controversy between parents and experts, for instance saying "The `experts' are wrong, and parents are right." presuming parents are opposed to the allegedly radical agenda of comprehensive sex education. In fact, nearly all parents, even very conservative parents, favor school sex education that teaches birth control: 89% of all parents, more than 80% of Born Again Christian parents, and 51% of parents who call themselves politically very conservative.

Second, Dr. Grossman identifies herself in this book as an Orthodox Jew. I find it strange that she spends an entire chapter lambasting the sex education advocacy group SIECUS for encouraging sexual experimentation rather than abstinence when the only sex education curriculum developed by Orthodox Jewish institutions is based on SIECUS guidelines (Life Values and Intimacy Education sponsored by Yeshiva University's Center for the Jewish Future, published by KTAV, all institutions considered arbiters of "Authentic Judaism"). She does not try to reconcile this discrepancy, I suspect because that would blur the simple dichotomy she is trying to create between religion/parents/tradition (=good) and academia/sex education advocates/SIECUS (=bad).

Third, her chapters on homosexuality and gender identity, the latter entitled "Genderland", are problematic in ways beyond the scope of this review. She cites some legitimate research such as Lisa Diamond's fantastic 10 year longitudinal qualitative study of lesbian and bisexual women published in the 2008 book Sexual Fluidity: Understanding Women's Love and Desire. Diamond found that nearly all of her women subjects' sexual orientations seemed to change spontaneously. Grossman uses spontaneous sexual orientation change among women to bolster the case for attempting to induce changes in sexual orientation among both men and women. Besides the spontaneous vs. attempted induced changes difference, Diamond looked only at women. Grossman lists many differences between men and women in the realm of sexuality earlier in her book, all of which would imply that a study of women's sexual orientations has no relevance to men's sexual orientations. Of course mentioning NARTH is a total non-starter.

This book does make some valid points and could be readable if all the alarmist bits were pulled out and the rest toned down. As I stated in my review of her previous book, I don't think that her points are repressed at the level of academic research, but as in many areas perhaps research simply is not adequately disseminated: this certainly wouldn't be the first area where quality of health care suffered because practitioners followed their intuitions instead of evidence-based guidelines or the evidence was never disseminated in the first place.

Cutting out the alarmism would make the book about 20% shorter but would give it a chance of being looked at by those she critiques. It seems like she's not interested in dialogue, just in fomenting alarm among the alarmed. Too bad. It could have been otherwise. She wrote this book while a recipient of a Clara Booth Luce fellowship, a fund that has funded moderate research by journalist Laura Sessions Stepp, also an affiliate of the moderate group National Campaign Against Teen and Unplanned Pregnancy.

What a wasted opportunity for dialogue.

Tuesday, August 25, 2009

Is the Pill worth it?

Birth control pills are the default contraception method to such an extent that many people use the word "contraceptives" to mean birth control pills to the exclusion of all other methods, not realizing that diaphragms, condoms, sponges, IUDs, and withdrawal, among others, also count as contraceptives.

Birth control pills come with a raft of side-effects including weight gain, depression, and potentially fatal blood clots (such as deep vein thrombosis and strokes), but their popularity seems to improve their perceived safety. A new book looks at the risks of birth control pills, given the big and small health risks of them.

Of course this view is not new at all. The Boston Women's Health Collective famously recommended in Our Bodies Ourselves using barrier methods only: you know exactly what they're doing and their effects end once you remove them from the body. The ultimate transparency. Plus they prevent STDs.

Unfortunately barrier methods besides condoms are rarely used: diaphragms are used by less than 1% of contracepting women and the only company making the cervical cap discontinued it due to lack of demand.

Perhaps this book will convince some of its readers into looking into barrier methods instead. Plus condom plus diaphragm is at least as effective as the pill in typical use. (Here's the math: effectiveness of each alone is 80% in typical use, so effectiveness of both together is 96% (1-(1-.8)^2=.96), which is better than the 94% typical use effectiveness of the pill cited in the article.)

Monday, August 24, 2009

Health communication in action

One of the standard anti-tobacco initiatives is to have graphic pictures and statements on cigarette packages to warn consumers. This dialogue shows one effect of the warnings.

Supermarket | London, UK

Me: “Can I help you, sir?”

Customer: “A packet of 20 Marlboro Lights, please.”

(I hand him the cigarettes.)

Customer: “Wait, I don’t want these ones.

Me: “Why? They’re Marlboro Lights. Did you change your mind?”

Customer: “No, I don’t want ones with this health warning about cigarettes causing impotency.”

Me: “Ok. Do you want ’smoking harms those around you,’ or ’smoking causes testicular cancer?’”

Customer: “Give me the ‘harms others’ ones.”

I'm not sure if that dialogue implies that the messages work or not.

Monday, August 10, 2009

Bar mitzvahs as the Jewish Rainbow Party?

Brandeis sociologist Shulamit Reinharz writes in 614 magazine, the magazine of the Brandeis women's research institute, that Jewish girls are giving oral sex as a bar mitzvah present, a topic people have been speculating about since at least 2005 (for instance, this 2005 David Brooks column is skeptical of what sound like old rumors even then.) Without better substantiation than the vague assertion from an unnamed Brandeis student that oral sex at bar mitzvahs is "common", it sounds like another rainbow party urban myth.

As head of a research institute, I'm surprised Professor Reinharz couldn't spare even a work study undergrad to investigate whether this claim has any basis whatsoever before raising alarms about it, much less publishing it under the name of an institution that might be considered an authority on "Authentic Judaism."

Early marriage reactions

Dallas TV news story giving reactions to early marriage idea, especially concern that they are pushing women away from education and towards early motherhood. Orthodox Jews have been promoting early marriage for a long time, and anecdotally I know that plenty of Orthodox Jewish women who marry young do go to medical school or other career pursuits they were planning on anyhow. It would be an interesting study to see whether marriage deters any from as extensive a career. My anecdotal impression is that married women get degrees from impressive schools but may be less likely or less interested in reaching the tiptop of their careers. So they will become a psychiatrist or internist or pediatrician with an MD from a top school, but may not become a neurosurgeon or med school professor.

Monday, August 3, 2009

Sociologist suggests lowering age of marriage

Mark Regnerus, one of the world experts on the sexual behavior of Evangelical Christians, wrote a long article in Christianity Today that states a few important facts.

1. Evangelicals are only slightly more sexually conservative than other Americans: about 80% have premarital sex by his estimate, and other estimates have higher numbers.

2. On average, like most Americans, Evangelicals have increased their average age at first marriage by 5 years, which goes along with a change in the view of marriage. As Regnerus puts it, "Most young Americans no longer think of marriage as a formative institution, but rather as the institution they enter once they think they are fully formed."

3. Women who want to get married have trouble finding men because 60% of evangelical young people are female: 3 women for 2 men.

My addition: recent research from Journal of Evolutionary Psychology indicates that a favorable male:female ratio alone may cause men to dally in making commitment to marriage, as is predictable.

The implications of these facts are not straight-forward because there's little good research on the subject of age of marriage, so conclusions are necessarily speculative. His conclusion is that people should get married earlier. My conclusions are that marriage age among evangelicals will probably stay high until there is an equal gender ratio, but there's unlikely to be an equal gender ratio because across societies women are in general more interested in religion than men, so pronouncements about what should happen aren't useful.

Just stating these facts may help to reframe the abstinence discussion.

Thursday, July 30, 2009

So we're the majority, now what?

Now that it's official that there is no money allocated to abstinence-only sex education, reproductive health advocates are firmly in the majority. Two articles that came up on my news alert email show contrasting approaches.

The first criticizes the National Campaign to Prevent Teen and Unplanned Pregnancy, which is a moderate organization that summarizes research on which sex ed programs are effective. They don't rule out that there might exist abstinence-only programs that work, but they say simply that there's no evidence that they work, and that moderation is why almost everyone trusts them.
This article doesn't see that moderation as quite so benign, saying they are not much better than the abstinence-only camp, calling them sex negative and saying they engage in "slut shaming", and that relationships don't turn out better if you wait to have sex until the 50th date instead of the 1st. That last question is an interesting one; as far as I know, there's no academic research on it, but I'd love to see the grant entitled, "Maximizing romantic returns: An investigation of the optimal time in a dating relationship until young women should put out." (Naturally to avoid confounding, the project would need to use matched sampling.)

The second articletalks about how complicated young women's sexualities are now, perhaps summarized as too much information without enough knowledge and wisdom. Women who initiate sex early do so under coercion, even without actual coercion many adolescent women don't feel comfortable saying no, and that when they say yes it is hesitant; she puts this well, so I will quote her:

The "yes" to sex and sexuality I hear young women often express sounds like the way many of us who took other languages in high school and trying to speak them in the country of their origin in our later years. Like asking with a feigned confidence where the drivel is when we wanted to ask where the bathroom was.

BGLT culture is more available to BGLT teens, yet only in certain places; women's bisexuality is accepted only as men's entertainment; and transgendered teens feel pressure to transition young, before age 18. Uniquely, she also emphasizes that teens' relative lack of responsibility compared to past generations (e.g., delays in moving out and getting a job) does not prepare them to take responsibility for their sexualities when the stakes are higher. Overall a fantastic summary: lots of questions, few answers other than the suggestion of communicating to teens that we understand that things are complicated.

When reproductive health advocates are in the minority, we show the status quo's failures. Even if it were right, the first article is not constructive; engaging in such divisiveness is a waste of a valuable opportunity to improve the situation. By contrast, the second article is constructive by laying out current problems of teen sexality in all their complexity. Now to move on to address them.

Abstinent for a year

Another book in the genre of people chronicling a year in which they do something unusual. This book is about being abstinent for a year Chastened: No More Sex In The City by Hephzibah Anderson. According to the review:

Perhaps underpinning many of her own attitudes, Anderson writes authoritatively on 1990s ladette culture, that terrible, capricious period which spawned a sub-species of women for whom boozing, brawling and trawling for men was worn as a badge of honour (I can say that, I was one too). "We may have been sexually empowered, but we were also emotionally frustrated," she reflects. Her contemplation of the disempowerment of romantic courtship which has stemmed from technological advancement also rings disconcertingly true. "As if sitting by the phone weren't bad enough, now we had to take the phone with us and hear its silence in cafes and bars," she writes.

Its conclusion is "Chastity belongs back in the mainstream as a valid form of sexual expression."

Teen-written sex ed site: sexetc.

Teen-written sex ed site includes an article "Kissing: are you missing out on life's simple pleasures" imploring readers to slow down and smell the roses; another article covers what abstinent teens do. One quoted teen says, “Now that I’ve been in a relationship for over a year and we’re considering becoming sexually active, I realize that my sex ed experiences made me terrified of sex. My teachers made it seem like everyone had an STD, and that contraceptives are expected to fail. If it weren’t for my own reading, I wouldn’t know what kinds of contraceptives are available.”

It's neat to read a quote by a real teenager illustrating what the GAO talked about in how inaccurate and negatively slanted abstinence education is.

Monday, July 27, 2009

LA County implements STD tests by mail

Women up to age 25 anywhere in LA County are eligible to receive a free home testing kit so they can test themselves for chlamydia and gonorrhea. The Don't think, know project is modeled on the I want the kit project started by my colleague Charlotte Gaydos at Johns Hopkins.

The testing kit arrives in an unmarked envelope. They swab themselves, mail it back, and get their results back via an 800 number or the internet.

Hopefully the LA project will expand also to men, as the Hopkins project did.

"True Lunch Waits"

Study: Abstinence-Only Lunch Programs Ineffective At Combating Teen Obesity, a brilliant story in the Onion. The entire thing is fabulous but I love this part:

"I'm never ever going to eat, because eating is wrong, and I'm worth more than a chicken sandwich with asparagus and rice pilaf," Woodbridge seventh-grader Tracey Holmes said. "I heard Jennifer Hines eats all the time, like 50 times a day. I heard she eats all her ice cream upside-down, though, so she doesn't get fat. That's how it works."

"It's really hard, though," Holmes added. "I get so hungry sometimes. Especially after hours and hours of unprotected sex."

Thanks to Arthur for forwarding it.

Thursday, July 23, 2009

Increasing autoimmune diseases?

This blog is usually about teen sex, but I'm also interested in the speculation that allergies and autoimmune diseases have increased in recent years, so sometimes I write about those.

A study published this month found evidence of such an increased prevalence of one autoimmune disease in a sample of men. They took old blood sampled from men at an Air Force base just after World War 2 (1948-1954) and used as a comparison group men currently at similar ages and men with similar date of birth. They tested the blood for two indicators of celiac disease, an autoimmune disease: tTGA, followed with a second test (EMA) in only the tTGA positive and weakly positive subjects. I presume that they know that these tests have similar rates of false negatives and false positives in 60 year old blood as in fresher blood.

They found more than 4-fold greater prevalence of celiac disease as judged by this test: 0.2% in the old blood and 0.9% and 0.8% in the new blood. Since the higher rates were found in the similar age comparison group, that finding provokes the question whether the subjects from the air base went on to develop celiac disease, but they don't have blood samples to answer that question.

I am curious whether this finding holds up in other large collections of old blood, (and also whether in 60 years their current samples of new blood test the same way.)

As a reader pointed out: the Air Force cohort was healthier than the contemporary young cohort due to having been pre-screened as part of their Air Force physicals. While this study's stated purpose is to be looking for asymptomatic celiac disease, there is of course a spectrum of non-specific symptoms, some of which may have caused the Air Force to screen people out and they would not have been screened out of the contemporary young cohort. It's too bad they don't have access to a contemporary Air Force cohort, though of course the Air Force standards might have changed over time. The only way to know whether this is a real effect is to repeat the study in different samples with different types of biases and vulnerabilities.

Since we don't know the reason for the higher prevalence of celiac today, the takeaway may be to live more like they did in the late 1940s including those swell hats and suits. If the increased prevalence is from the increased cleanliness we have now versus 60 years ago, use plain soap and toothpaste rather than the ones with antimicrobials and follow fewer food safety rules just as they did in the old days.

They also found that the 0.2% with presumably untreated celiac went on to die at 4 times the rate of the people without it; while they were dealing with small numbers, the mortality rate was at least twice the celiac negative (Hazard Ratio 3.9 with confidence interval (2.0, 7.5)), so this is important.

[Photo from Georgia Encyclopedia.]

Tuesday, July 21, 2009

Late night Congressional abstinence exchange

Congress abstinence debate had the following exchange:

Later in the debate, Rep. Diana DeGette (D-Colo.) said federal dollars should only fund sex education programs -- including abstinence-only ones -- in schools that have proof that they cut pregnancy rates. She noted that abstinence-only sex ed came along in 1981.

[Joe] Barton [R- Tex.] interjected that abstinence-only has been around much longer than that, at least since his dating days. "Every girl I dated practiced it," he said. "And it was very effective, because when I went to pick them up, their fathers reinforced it on me. So it does work and it has been around much longer than the 1980s."

"Maybe," DeGette suggested to Barton, "it was [practiced] on a case-by-case basis."

Friday, July 17, 2009

"Hey, Lloyd, let's run a sloppy study": FDA female condom advisory panel

The STD Center visited the FDA advisory panel on the new female condom in mid-December 2008, and a good time was had by all. The FDA makes the transcripts available, though they're somewhat difficult to find. Here is the main site for all the transcripts prior to the current year, and this site is for this year.

My favorite moment is at the very end of this transcript and at the very beginning of this one: Ralph D'Agostino expresses concern about approving devices supported by "sloppy" studies. He makes a very good argument earlier on (right before this quote) that people having difficulties with the female condom might drop out and that could affect the final results, and asks whether they usually impute for missing data and why they didn't do that here. His final conclusion is a policy conclusion:

DR. D'AGOSTINO: Yeah, but what I'm concerned about is that somebody reading this transcript may say, hey, Lloyd, let's run a sloppy study; we already have approval, already have, you know, precedent for it. I think that what we want is just, you know, give an impression that there are better ways of getting interview data. There are better ways of chasing down the dropouts and so forth, and I'm concerned that we're not emphasizing that. I may not differ from the bottom line where we're going. It's just that the signal may be that we have a better, more positive view of the study than we probably should have...I'm not arguing with the final vote, the way the final vote might go. I'm arguing with the sense that this study has more merit than it actually has, and getting that across is what I think we should need to do.

Thursday, July 16, 2009

Virtual virginity pledge

There's an ivirginity pledge application for the iphone catering towards the British virginity pledge audience. The bloggers have already had a field day speculating on what kind of activity this virtual purity ring will prevent. Interesting that it's a British group. Wonder if American groups will follow.

Thursday, July 9, 2009

White males are perceived as more competent

Teaching evaluations for statistics professors are almost always lower for women than for men. There's a similar finding by researchers at U Wisconsin Milwaukee that customers in general are more satisfied with the performance of white men than minorities or women.

The story shows the white male researcher's picture, giving them the opportunity to do a meta-study to find out whether including the picture makes the reader more convinced of the correctness of the findings.

Thursday, July 2, 2009

Virginity misconceptions

RH Reality Check has an interview with Jessica Valenti about the role of virginity in society. The cultural criticism part of the interview addresses a complex reality with many layers, but addressing some simple facts I think she may misunderstand the evidence to some degree:

1. The social science says that sexual initiation is important, both the age and circumstances. The age of sexual initiation is associated with concrete negative health outcomes, such as increased likelihood of STDs, pregnancy, less likelihood of using condom even in subsequent relationships. In many cases women, disproportionately African-American, have early sexual initiation within coercive relationships, often with men over 18.

2. Girls and women are more vulnerable than men in many sexual contexts: getting a woman pregnant can cause financial hardship to men, but women have more immediate consequences and educational/advancement consequences. Transmission rates of STDs to women are higher than to men for many diseases. While men are more likely to have symptoms of chlamydia and gonorrhea, these diseases are more likely to have lasting consequences for women than for men, the combination of which means that a woman might have lasting consequences without ever knowing. Intimate partner violence (IPV) is more common and more severe for women than for men.

As a female statistician who was a physics major in college, I know about sexism. On the other hand, there are some gender differences that are real. I also supported Larry Summers in that debacle.

3. My impression is that virginity is a concept that Evangelical Christianity applies to both men and women, and is concerned with both equally. That's not as much my area, but it's been my impression.

Tuesday, June 30, 2009

Sweden's mandatory sex ed: a social conservative's nightmare

This is what the Evangelicals are afraid of US sex education becoming: mandatory with strawberry-flavored condoms handed out by teachers. The article also notes that tax money subsidizes sex toys sold in state-owned pharmacies.

According to the article, before the legal change "Twenty-seven percent of immigrants’ daughters are kept from participating in some school subjects." That's a large number. Does that mean boys were allowed to go?

Needless to say, the US isn't even close to being like Sweden and would never remove the option for students to opt out. Given the high rates of chlamydia and other STDs among high school students, it would be great to hand out condoms in sex ed classes, but that would never happen and if it did they would be the most boring condoms possible.

Evangelical Christianity and self-selection

Evangelical Christians have the goal that everyone within their fold adhere to norms such as abstinence from premarital sex. Clergy and active congregants adhere to the norms most of the time, but many evangelical teens have sex lives only slightly more conservative than the average American or European teenager. I've long wondered whether the reason for this discrepancy is that evangelical Christianity includes many people who, for whatever reason, are unlikely to adhere to all the norms.

Comparing religions can only be done in the spirit of "All models are wrong, but some are useful", so with that in mind I thought about religious self-selection in the context of some youtube videos making their way around some progressive Jewish blogs with enthusiasm and modern Orthodox blogs with hesitant, tepid approval, apparently spurred by an article in the Forward, a US Jewish newspaper.

This is a fantastic video of a secular Israeli girl band called "Woman of Valor" (Prov. 31) singing "Open our eyes to your Torah, cause us to cleave to your commandments, and unite our hearts in love and awe of your name" a line from the liturgy repeated over and over*. They also sing "On the rivers of Babylon" (Psalm 137) and "The angel who saved me" (Genesis 48). In the US, I would guess that this would be fairly standard evangelical Christian popular music, but in Israel it is Tel Aviv secular, performed at the Gay Pride parade, and so extremely exciting and outrageous**.

If the evangelicals are including the equivalent of the Tel Aviv secular who obviously connect to some aspect of the Bible and yet for whatever reason are not interested in some of the religious norms, programs like virginity pledges may reach only the Jerusalem religious who would abstain anyhow.


(*) It begins "That we shouldn't ever be bashful or ashamed or stumble." There's also a rap segment in the middle that isn't a text also about connecting with the divine.

(**) Comments on the video are outraged. My translation of some of them:
- If they really believed what they sung, they would dress differently and they wouldn't dance like that and they would seem even slightly like daughters of Israel. G-d should have mercy on us, what a desecration of G-d's name.

- When someone sings to open our eyes to your Torah and be caused to cleave to your commandments when she is, pardon me, half naked is really not respectful. It's like going to the synagogue to pray in a bathing suit. Does that seem right? It's like the Maimonides's example of going into a ritual bath holding an impure reptile, doing something good but in an improper manner.

- I don't understand the connection between the meaning of the text and the clothing. They say they want to be open to G-d's commandments and they are not fully dressed.

Monday, June 29, 2009

Funding transformative research

NY Times article on conservatism in science funding. To add to the chorus: it's not curing cancer or anything, but my virginity pledge research would have probably not gotten funded by NIH. I didn't expect to find that virginity pledgers would lie about having had sex, so I wouldn't have known to look for that and I wouldn't have been able to write a proper research proposal to do that.

Friday, June 26, 2009

Congratulations to North Carolina

North Carolina passed a bill mandating that 7-9th graders be taught both abstinence methods of contraception and STD prevention, and the governor is expected to sign it. This bill is different than the original proposed, which had required that all schools offer two sex ed classes that parents would choose between. This bill just allows parents to pull their children from the STD/pregnancy prevention portion of the class.

The current policy for the past 15 years has been that school districts that wish to teach birth control in school must go through a separate approval process to be able to teach birth control.

It is sad that no Republicans voted for the bill. I wonder whether there is any compromise legislation or any research that would convince Republicans to allow teaching birth control in schools.

The evidence from RAND's intervention to teach parents how to teach sex education to their adolescents finds that even with an 8 week program for these parents who volunteered to participate, the majority of parents STILL didn't teach their kids how to use condoms. And this is a group of parents cherry-picked for their motivation. Other parents would likely do worse. No matter what your ideals are about parents' duties towards their adolescents, the reality seems to be that if you want condom use to be taught, you have to put it in the schools. Or let them learn on youtube or in an STD clinic waiting room. Watching instructional videos in the waiting room of an STD clinic reduces the risk of repeat visits, after all.

Tuesday, June 23, 2009

Reformulating or rebranding abstinence

There's a vivid and interesting piece in the Nation about the abstinence movement's attempt to rebrand/reformulate itself. At times, I laughed: Jessica Valenti writes dynamically and compellingly. She raises some important points, though I don't agree with everything she says. (E.g., I think that the trend of traditional religions using feminism to promote traditionalism is complex and subtle. Her take is that "the virginity movement is ... a targeted and well-funded backlash hellbent on rolling back women's rights using modernized notions of purity, morality and sexuality.")

The central point of her article is crucial: the abstinence movement recognizes that it needs to give accurate information about contraception, which I see as a terrific coup for the cause of scientific accuracy. Perhaps the reformulation is being done with good will: they see problems with current version and honestly they want to make it better for the sake of teens' health. Or perhaps Valenti is right and this recognition is just lip service and won't change what they are actually doing, though even lip service is good.

Whether reformulation or rebranding, this change calls for vigilance. The abstinence-only movement is taking the "only" out of their label: now it's "abstinence centered" which is confusingly similar to "abstinence-plus" or "abstinence-based" which mean comprehensive sex education, so it will take an extra moment to even determine whether a curriculum intends to be comprehensive or not.

If there are inaccuracies in the new curricula, they may be more subtle. The most productive thing reproductive health community can do is make sure that what is taught in schools is accurate. Some states mandate that all sex education gets reviewed by clinicians for accuracy, but others don't. If all states established such requirements of review by medical experts, that would make it a moot point whether the abstinence movement is doing a cynical rebranding or a good will reformulation of its movement.

Utah's sex education

Utah is considering new sex education approaches. They recently changed their sex education laws to allow teaching of contraception in school sex education classes, but teachers are still apparently afraid of saying the wrong thing and getting fired, so the new sex education law is aimed at mandating teaching contraception. The Salt Lake Tribune editorial board endorsed the bill.

I spoke with a group that is helping out the legislature about ways to bridge the ever-present gap between conservative and liberal views of sex education: conservatives are afraid that teaching contraception encourages kids to have sex, and they were confused that some programs that teach birth control actually cause kids to DELAY sex. The most obvious explanation, of course, is that teens are terrific detectors of propaganda. They want to make their own decision, but they need to be given the autonomy to do so, not just told what to do. As everyone knows, to order a teen to do something without giving them alternatives risks losing the chance to influence them at all.

I also suggested that they include parents in the sex education curriculum somehow, such as through take-home assignments that adolescents complete with their parents. It's a good idea to get parents and adolescents talking about sex, and it may reassure conservatives that the role of schools and parents in sex education is complementary.

I'm excited to see what happens. Utah!

Meanwhile, Oregon just passed a new sex education bill that requires that all abstinence sex education must also include "other material and instruction on contraceptive and disease reduction measures."

Decreased contraceptive use among teens

I was pleased that the NYT editorial board highlighted the recent study by John Santelli, Mark Orr, Laura Lindberg, and Daniela Diaz about decreased use of contraception in an analysis of the Youth Risk Behavior Survey. As the media reports it, Santelli and collaborators found that fewer teens are using contraception than previous highs a few years ago, and the speculation is that the decrease is from abstinence-only sex education.

Other research certainly indicates that abstinence is one plausible explanation for the decrease in contraceptive use. The trouble is that there are many other possible explanations, but the trend data on teen sexual decisions is so poor that we'll never know which explanation is responsible for this particular decrease in contraception use. The survey used by Santelli has at most a dozen relevant questions, and any information beyond that gets lost to the mists of time.

Some teens get pregnant because they want to. It's not a question of not knowing how to use birth control; they want someone to love them or to establish themselves as adults. Other teens get pregnant because they are in coercive relationships with older men who support them financially --- perhaps especially relevant in insecure economic times --- and the men want babies. I heard a story from a Maryland public school teacher about a 14 year old girl in her class who recently got pregnant because her 20+ year old boyfriend and his mother wanted her to; the boyfriend's mother wants to take care of the baby and the girl's mother is indifferent to the situation.

These stories represent more fundamental social problems than simply inconsistent or incorrect condom use, but the current data is so poor that if one reason for the lower contraceptive use was that more girls are being coerced by older partners to get pregnant, we would have no way of knowing. Such issues of teen pregnancy are not liberal or conservative, but some conservatives are opposed to funding surveys that would collect data to better understand the issues because they are uneasy about asking questions about sex to teenagers. If they could better understand the implications of their opposition, and what a good investment it would be to understand teen pregnancy better by funding an annual survey that monitors issues exclusively relevant to teen pregnancy and STD prevention, perhaps we could start to decrease the rate of teen pregnancy.

MBAs and evangelical teens both take pledges

I was waiting for someone to make this comparison between virginity pledges and the pledges some business schools are offering to help their students not grow up to become Bernie Madoff and the subprime mortgage industry.

Truth be told, we don't know whether pledges and other one-time events affect behavior in general, but the common sense view that character is built slowly and reinforced over time would seem to prevail. We don't have as much knowledge about hidden areas of life such as sex and white collar crime, but we all know that New Year's resolutions can be helpful but not decisive.

The next stage in this comparison I'm still waiting for: a good stand-up routine comparing MBAs and evangelical teens, speculating on how you could do joint events to encourage both not having premarital sex and not becoming white collar criminals.

Friday, June 19, 2009

Forever relevant

A retrospective look at Judy Blume's Forever, a book about a couple's first love and decision to have sex. (The article was published 4 years ago, but is making the rounds again through reproductive health blogs.)

What the article does not mention is the issue of sex outside of romantic relationships which has become more normative in the past decade or two. What I like the most about this book is that having such a healthy relationship of communication portrayed in the book creates an ideal that might discourage teens from pre-relationship and non-monogamous sex. Adolescents have famously short time horizons, and will wait for marriage only extremely particular conditions and maybe not even then, but waiting for a devoted and loving girlfriend or boyfriend rather than just a sex partner may be attainable.

Obesity and "light" food

Some people have speculated that the idea of light or reduced calorie food is partially responsible for the obesity epidemic, but usually with regard to processed food with the famous ``Snackwells effect'': people eat a whole box of low fat cookies instead of 2 Oreos.

I started thinking about that after baking a cheesecake. I used this recipe from Rose Levy Birnbaum with full fat cream cheese and sour cream but no crust because I grew up without pie crusts. I never have foods like full-fat cream cheese and sour cream in the house and I felt so decadent buying them and putting them all in a bowl together, so it was with a morbid curiosity that I decided to compute the calories: 12 slices = 240 calories each, 8 servings = 350 each. If I'd used Neufchatel cheese which is an almost invisible substitution, 8 servings = 300 each.

That didn't seem like many calories, so I decided to compare a light cheesecake I'd recently heard about from the Best Light Recipe. The light recipe uses cottage cheese, yogurt, and Neufchatel cheese, so clearly they must save some calories, yet according to their calculations the cheesecake serves 12 and has 340 calories in each slice, 100 calories more than Birnbaum's recipe. Both recipes get made in a 9 inch dish. Maybe slices of the Best Recipe are marginally taller, but like glass width I'm guessing that's the type of size difference that people don't perceive readily.

So it's not just the Snackwells effect: the low-fat version doesn't even have less calories, and could have more. I've made my decision: when it comes to dessert, full fat only. The rest of the time I can scrimp and use 1 T oil when the recipe calls for 1/4 c.

Here's my calculation of the Birnbaum cheesecake calories for those who want to check my math:

  • 1 lb cream cheese, 1600 (1120 if Neufchatel cheese)
  • 1 c brown sugar, 829 (774 if white sugar)
  • 1 T cornstarch,
  • 3 eggs, 225
  • 1/2 T vanilla
  • 1/4 t salt
  • 1 lb sour cream, 900

Total calories: 2855 (2375 if Neufchatel cheese).