When science news isn’t new

The Herald (from the Telegraph) says People with divorced parents are at greater risk of strokes, study finds

The study is here and the press release is here. It uses 2022 data from a massive annual telephone survey of health in the US, the Behavioral Risk Factor Surveillance System, “BRFSS” to its friends.

Using BRFSS means that the data are representative of the US population, which is useful.  On the other hand, you’re limited to variables that can be assessed over the phone.  That’s fine for age, and probably fine for parental divorce.  It’s known to be a bit biased for BMI and weight. The telephone survey doesn’t even try to collect blood pressure, cholesterol, or oral contraceptive use, all known to be risk factors for stroke.  And if you call people up on the phone and ask if they’ve ever had a stroke, you tend to miss the people whose strokes were fatal or incapacitating (about a quarter of people die immediately or within a year if they have a stroke).

Still, the researchers collected some useful variables to try to adjust away the differences between people with and without divorced parents.  As usual, we have to worry about whether they went too far — for example, if the mechanism was via diabetes or depression, then adjusting for diabetes or depression would induce bias in the results.

This sort of research can be useful as a first step, to see if it’s worth doing an analysis using more helpful data from a study that followed people up over time — either a birth cohort study or a heart-disease cohort study.  It’s interesting as initial news that there’s a relationship — though you also might think adverse effects of divorce would get smaller in recent decades as divorce became less noteworthy.

All this is background for my main point.  While looking for links to published papers, I found that one of the same researchers had done the same sort of analysis with the BRFSS data from 2010 and published it in 2012. They found a stronger association twelve years ago than now.  I don’t know about you, but I would have appreciated this fact being in the press release and in the news story.