The Alzheimers Association’s International Conference is underway in London which might explain an uptick in reports on Alzheimer's in the popular media. There are reports in the Washington Post, NPR, BBC, Medscape, even Yahoo food. These reports all share a salient quality; the reporting is based on clinical abstracts  rather than the actual papers or datasets. Do these media reports clarify or confuse? Consider two abstracts.
Kaiser Permanente, a large California based health system, looked at records for 6,284 patients, including their health data at mid-life. They compared the findings of dementia with the infant mortality of the patient’s birth state. High infant mortality (HIM) was coded as a binary value where a yes represented one of the top 10 states. There was no association between HIM and dementia in white patients, but a significant association for blacks. The authors concluded:
“In a cohort of elderly individuals, Blacks born in states with the highest levels of race specific infant mortality rates had 40% increased risk of dementia, though all individuals subsequently moved to California. Early life conditions may contribute to racial inequalities in dementia incidence and needs to be further investigated.”
Is it fair to report the conclusion? Could the data be impacted by the sample size, after all, they looked at five times more whites than blacks? Why treat HIM as yes, no – would the results have been different if HIM was a gradient? We don’t know. Were there morbidities and confounders that differed significantly between the groups? We do not know.
A longitudinal study (Wisconsin Registry for Alzheimer's Prevention – WRAP) examined relationships between lifetime stress and cognition among African American and non-Hispanic white adults.The authors write,
”Even within a small, highly-educated sample, African Americans report experiencing more stressful events and exacerbated stressor-associated cognitive dysfunction, with each reported experience equivalent to more than four years of cognitive aging.”
What a great quote, especially since each stressful event results in a seemingly dramatic cognitive aging. What is not mentioned, is once again the sample size. While the abstract proclaims 1,320 participants only 82 were African-American (6.2% of the entire study group) with more stressful lives and cognitive decline. Perhaps that is why the adverse effects were “attenuated” when the whole group was analyzed. And as with the other study, there is no information on the characteristics of the groups or the validation for the Lifetime Stress Index used to quantify stress. Is this fair reporting or click bait?
In another Caveat Lector way, consider the opening line for the web page presenting these abstracts,
“A series of studies reported at the 2017 Alzheimer's Association International Conference (AAIC 2017) in London confirm racial inequities…”
Inequity is about fairness and justice; it has strong cultural connotations. The studies report on differences, perhaps cultural or genetic or some combination of events we may never fully appreciate. But using the word inequity belies a cultural agenda that represent a conflict of interest in how results are discussed. These abstracts are designed for media consumption, whether they shed light or shadow is lost in the need to report. Science journalism slights its consumers, the readers, when it relies on abstraction by authors rather than primary sources.
 By their nature, these sorts of clinical abstracts are preliminary reports that haven’t been published nor undergone peer review. Certainly, this is a fact that should be mentioned in any reporting.