A survey of physicians show a one-third reduction in harmful outcomes to be a clinically important difference for statin therapy.

OBJECTIVE: To establish a minimal clinically important difference (MCID) for outcomes of statin therapy with physicians using a cross-sectional design. The MCID was defined as the smallest benefit of statin therapy that would result in physicians recommending it to their patients after considering potential harm and cost. STUDY DESIGN AND SETTING: A self-administered questionnaire was sent to family practitioners, internal medicine specialists, and cardiologists practicing in Hamilton. They provided an MCID of statin therapy using clinical scenarios based on 5-year risk of vascular outcomes, namely coronary death, nonfatal myocardial infarction, stroke, and coronary revascularization. RESULTS: Two hundred nine physicians participated, of which 638 were initially approached. Physicians would recommend statin therapy if it would at least reduce the relative risk of vascular events by about one-third. For patient scenarios involving a 30%, 13%, and 5% baseline risk of developing a vascular event in 5 years, physicians would recommend treatment if it would reduce the baseline risk by 31.4% (standard deviation [SD], 19.8), 34.6% (SD, 18.0), and 46.2% (SD, 24.6), respectively. CONCLUSION: Physicians were consistent in their choice of MCID for statin therapy across vascular events. They required a larger benefit of statin therapy for patients at a lower baseline risk (5%) of developing a vascular event before they would recommend treatment.