In Against Health: How Health Became the New Morality (Biopolitics, Medicine, Technoscience, and Health in the 21st Century) , there's an essay "Against Global Health?" by Vincanne Adams.
The introduction was a bit of a slog, but I think the point was that if "health" is defined as something which can and should be given to people regardless of what they think in the matter, the results can be presumptuous.
While she may be overly invested in the way things are usually done, she brings up some disquieting points about the ways insisting on double-blind tests can go wrong. For example, she mentions a project to evaluate training in safe infant delivery techniques in Tibet which was scuttled because not enough women were dying to get a good power calculation.
She describes experiments which are done in isolated communities because that's where the researchers can be reasonably sure that the subjects don't have alternative sources of care which would foul up the double-blinding. This does seem like a drunk and lamp post problem.  More generally, the concern is that actual care is delayed in the search for perfect information. Admittedly, it's hard to be sure about how to balance searching for information with taking action, but it strikes me as a problem that's worth some thought rather than just assuming that double-blinding is a reliable improvement.
 Is there a standard LW term for searching where it's easy to search rather than where the answer is likely to be?