I assume that most people would agree that variation is acceptable when patients make different personal choices—for example, whether to have screening for Down’s syndrome or prostate cancer. Likewise, I take it that variation is not acceptable when compelling evidence of cost effectiveness is available. These points I take as “self-evident truths” and turn to the interesting question that relates to the acceptability of eclectic practice when the evidence is not compelling.

When I started out in practice, some clinicians recommended bed rest for threatened miscarriage while others advised women to continue with normal activities. Some mothers were encouraged to nurse their babies prone, others supine. Should mandatory compliance with one or the other practice have been imposed in each …