I argue that advancing “second-generation” or mechanistic causal knowledge of individual outcomes requires a comprehensive research programme that uses a variety of different methods in addition to the ones described in the paper under discussion. I also highlight that environment-focused approaches can be as instrumental in identifying potential phenotypic causes as gene-focused approaches.

Over the past decade, a series of studies have found that physicians-in-training who work extended shifts are at increased risk of experiencing motor vehicle crashes, needlestick injuries, and medical errors. In response to public concerns and a request from Congress, the Institute of Medicine conducted an inquiry into the issue and concluded in 2009 that resident physicians should not work for more than 16 consecutive hours without sleep. They further recommended that the Centers for Medicare & Medicaid Services and the (...) Joint Commission work with the Accreditation Council for Graduate Medical Education to ensure effective enforcement of new work hour standards.The IOM's concerns with enforcement stem from well-documented non-compliance with the ACGME's 2003 work hour rules, and the ACGME's history of non-enforcement. In a nationwide cohort study, 84% of interns were found to violate the ACGME's 2003 standards in the year following their introduction. (shrink)