Archive for October, 2010

Stats 101 for Policymakers

It’s a problem that is easy to recognize, but hard to get around: policy isn’t made by public health epidemiologists or statisticians. In between the researchers (who have their own biases) and the policy makers is a whole industry of  interest groups and advocates. Of course, I’ve been one of those advocates at times, as has pretty much everyone who has worked in public health or politics.

Why am I thinking about this? I just read “Interpreting health statistics for policymaking: the story behind the headlines” in the Lancet (available for free here) by Neff Walker et al. The paper outlines this problem:

Estimates would be more credible if they come from technical groups that are independent of the organisations that implement programmes and advocate for funds.

Maternal mortality is much more inequitably distributed than neonatal mortality, but does that mean we should focus on it more? Of course, some of this comes down to fundamental philosophical differences concerning whether we should concentrate our health investments where they will make the most difference in terms of absolute numbers of lives saved, or where they will make the most difference in terms of reducing health care inequalities.

Statements like “Maternal mortality is 100-fold higher in many low-income countries than in high-income countries” sends a clear message with respect to inequities, but no information about the absolute magnitude of the problem. Statements more useful to decisionmakers are those that use a standard metric to provide sets of meaningful comparisons. For example, the ratio of inequity between low-income and high income countries for deaths from severe neonatal infections is far lower, at 11-fold. In absolute numbers, however, two to three times as many lives are lost to neonatal infections each year (1·4 million) in developing countries than to maternal mortality (500 000).

It’s easy to criticize HIV/AIDS advocates because they’re such, well, good advocates. Example 1:

For example, a common practice is to present an estimate at the global or regional level and then to elaborate on it by giving a specific and often unrepresentative example. HIV/AIDS advocates talking about the eff ect of AIDS on under-5 mortality often use as examples countries in southern Africa where AIDS accounts for 30–50% of deaths in under-5s. But for sub-Saharan Africa as a whole, AIDS is thought to account for less than 10% of under-5 deaths.

Example 2:

Advocates of funding for [HIV/AIDS] often quote the cumulative number of global deaths from HIV/AIDS since it was first identified. But, if historical estimates were used for other diseases, the number of HIV/AIDS deaths would be small in comparison. For example, if the same statistical procedures were applied for pneumonia as for HIV/AIDS, the cumulative deaths since 1975 would be about 60 million—almost three times the estimated cumulative deaths from AIDS in the same time period.

They end the paper with a list of recommendations for how policymakers should consider health stats coming from advocates or any other source.


10 2010

Tuskegee in Guatemala

The news that a US government study in the 1940s involved injecting Guatemalans with syphilis has been circulating, and it makes my stomach turn.

Susan Reverby — the Wellesley historian who uncovered the fiasco — has made the draft paper available on her website: “‘Normal Exposure’ and Inoculation Syphilis: A PHS ‘Tuskegee’ Doctor in Guatemala, 1946-48,” which will be published in the Journal of Policy History in January.

From the introduction:

Policy is often made based on historical understandings of particular events, and the story of the “Tuskegee” Syphilis Study (the Study) has, more than any other medical research experiment, shaped policy surrounding human subjects. The forty-year study of “untreated syphilis in the male Negro” sparked outrage in 1972 after it became widely known, and inspired requirements for informed consent, the protection of vulnerable subjects, and oversight by institutional review boards.

When the story of the Study circulates, however, it often becomes mythical. In truth the United States Public Health Service (PHS) doctors who ran the Study observed the course of the already acquired and untreated late latent disease in hundreds of African American men in Macon County, Alabama. They provided a little treatment in the first few months in 1932 and then neither extensive heavy metals treatment nor penicillin after it proved a cure for the late latent stage of the disease in the 1950s. Yet much folklore asserts that the doctors went beyond this neglect, and that they secretly infected the men by injecting them with the bacteria that causes syphilis. This virally spread belief about the PHS’s intentional infecting appears almost daily in books, articles, talks, letters, websites, tweets, news broadcasts, political rhetoric, and above all in whispers and conversations. It is reinforced when photographs of the Study’s blood draws circulate, especially when they are cropped to show prominently a black arm and a white hand on a syringe that could, to an unknowing eye, be seen as an injection.

Historians of the Study have spent decades now trying to correct the misunderstandings in the public and the academy, and to make the facts as knowable as possible. The story is horrific enough, it is argued, without perpetuating misunderstanding over what really did happen and how many knew about it. What if, however, the PHS did conduct a somewhat secret study whose subjects were infected with syphilis by one of the PHS doctors who also worked in “Tuskegee?” How should this be acknowledged and affect how we discuss historical understandings that drive the need for human subject protection?

(Emphasis added.) And later:

Ironically, though, the mythic version of the “Tuskegee” Study may offer a better picture of mid-century PHS ethics than the seemingly more informed accounts. For Public Health Service researchers did, in fact, deliberately infect poor and vulnerable men and women with syphilis in order to study the disease. The mistake of the myth is to set that story in Alabama, when it took place further south, in Guatemala.

Interestingly, the episode happened during a period of hope in Guatemalan history — one of elections and land reforms, before decades of civil war that followed our overthrow of the democratically elected government:

The United Fruit Company owned and controlled much of Guatemala, the quintessential “banana republic,” in the first half of the 20th century. When the PHS looked to Guatemala for its research in the immediate post-World War II years, it came into the country during the period known for its relative freedoms; between 1944 and the U.S. led CIA coup of the elected government in 1954, there were efforts made at labor protection laws, land reform, and democratic elections. The PHS was part of the effort to use Guatemala for scientific research as they presumed to transfer laboratory materials, skills, and knowledge to Guatemalan public health elite.

And one last tidbit:

In reporting to Cutler after he returned to the States, he explained that he had brought Surgeon General Thomas Parran up to date and that with a “merry twinkle [that] came into his eye…[he] said ‘You know, we couldn’t do such an experiment in this country.’”60

Read the whole thing.


10 2010