Monday, December 2, 2013

New statin guidelines and other notable medical reversals

- Kenny Lin, MD, MPH

The recently published American College of Cardiology / American Heart Association cholesterol treatment guideline, which updates the National Heart, Lung, and Blood Institute's Adult Treatment Panel III recommendations that have guided clinicians for more than a decade, has generated controversy for several reasons: primary care groups did not participate in development of the guideline; several panelists had financial conflicts of interest; its cardiovascular risk calculator may substantially overestimate risk in certain populations; and the lowered risk threshold for prescribing medication, if adopted worldwide, could potentially result in more than a billion people taking statin drugs. American Family Physician will provide readers with concise summaries and critical analyses of the ACC/AHA guideline in future issues.

Family physicians who have grown comfortable with ATP III's "treat to target" paradigm for cholesterol management were likely surprised by the new guideline's "fire and forget" approach, which advises prescribing fixed doses of statins based on cardiovascular risk assessments and not routinely rechecking cholesterol levels. The latter approach is more consistent with the evidence from randomized controlled trials, but this change is, nonetheless, a significant reversal of an established medical practice. Although such reversals are surprisingly common, they can be unsettling to clinicians.

In an editorial in the December 1st issue of AFP, Drs. Caroline Wellbery and Rebecca McAteer review reasons for other dramatic reversals such as hormone replacement therapy and tight glucose control in diabetes, which include poor design and small size; focus on disease-oriented evidence, application of findings to nonstudy populations; unidentified harms; and economic factors. They have several related suggestions to help physicians avoid pitfalls associated with currently accepted practices that may be vulnerable to later reversal:

To minimize the dizzying impact of changing recommendations, physicians should focus on patient-oriented evidence, and not be distracted by disease-oriented evidence. Physicians should become familiar with the basic principles of good research, and avoid drawing premature conclusions from observational studies or studies with design flaws. Physicians should also recognize the pharmaceutical industry's influence on research studies and practice recommendations.