Association not causation.

摘要

In the article by Shalev et al, the authors improperly draw causal inferences from observational connections between statin therapy compliance and survival. Historically, associations of drug use and compliance with favorable health outcomes can depart from causal findings, not only in magnitude but also in direction (recall the hormone therapy "data" on cardiac events and dementia). Lower cognitive function (whether or not promoted by worse health) as well as lower conscientiousness portend both lower statin therapy compliance and greater mortality. In addition, unfavorable health factors predict risk of statin adverse effects,which are in turn linked to noncompliance, and do so disproportionately with high-potency statins. This forges a further link between lower compliance and higher mortality that is statin specific-and greater with high-dose statin use-but not attributable to statin therapy benefits. Creatine phos-phokinase and liver function test results are inadequate to exclude statin adverse effects associated with non-compliance, which are commonly gastroenterological and neurological.