Wednesday, March 19, 2014

Why conflicting guidelines can be good for patients

Many of the best-read posts on Common Sense Family Doctor have voiced my strong opinions regarding guidelines. After I left my position as a staffer for the U.S. Preventive Services Task Force in November 2010, it was three years before I was tapped for another guideline post, this time at the American Academy of Family Physicians. Recently I joined the AAFP's Commission on Health of the Public and Science, which formulates guidance for family physicians on a variety of topics, including clinical preventive services. My appointment coincided with the release of two high-profile guidelines on high blood pressure and cholesterol.

For most of my career in family medicine, nearly all physicians followed the same guidelines to manage these common risk factors for cardiovascular disease: JNC 7 and ATP 3, expert panels convened by the U.S. National Heart, Lung, and Blood Institute. After the JNC 7 blood pressure guideline was published in 2003, waiting for the release of the next iterations of these guidelines was like waiting for Godot. Then, in an abrupt move that was seen by some as wanting to avoid a public uproar similar to that caused by the 2009 USPSTF guideline on mammography, the NHLBI announced last year that it would no longer sponsor guideline development, and instead leave the process of translating evidence into recommendations to professional medical societies.

The result has been a fracturing of the longstanding primary care and subspecialist consensus on what to do for patients with high blood pressure and cholesterol. The new cholesterol guideline, published under the auspices of the American College of Cardiology and American Heart Association, quickly came under fire for recommending that clinicians base treatment decisions on a relatively untested cardiovascular risk calculator that could lead to a surge in statin prescriptions for older adults with normal cholesterol levels. In contrast, the hypertension panel elected to skip organizational endorsement and publish their guideline directly in JAMA. "JNC 8" endorsed looser blood pressure targets for older adults and rejected stricter targets for adults with diabetes and chronic kidney disease. Dissension within the panel became public when five members published a "minority report" that argued against abandoning the goal of a systolic blood pressure under 140 in older adults. As of this writing, it's not clear which medical groups will endorse or reject the new guidelines.

There has been much hand-wringing about the potential negative impact of conflicting guidelines. Whose guideline should doctors follow? How do we explain to our patients why guideline recommendations differ? When I worked for the federal government, these kinds of concerns engendered not-so-subtle pressure to "harmonize" or "align" existing discrepancies between official guidelines, such as those on screening for HIV and hepatitis B and C. Now, the USPSTF and the Centers for Disease Control and Prevention concur on whom to screen for these infections, but to align their new recommendations, the Task Force arguably lowered its evidence bar and drew conclusions from a weak literature base. The same thing seems to have happened in lung cancer screening, where USPSTF recommendations for annual CT scans in heavy smokers harmonized with guidelines from oncology, radiology and pulmonology groups but were later rejected for "insufficient evidence" by the AAFP (note: though I agree with this call, I was not involved in the AAFP's decision process).

Sure, it's easier for everyone when guidelines agree on what to recommend for a particular patient in a particular situation. But when “reaching alignment" is simply a euphemism for one guideline group exerting political pressure on others to fall into line, that isn't good for medicine or for patients. After all, it wasn't so long ago when medical groups marched in virtual lock-step to recommend menopausal hormone therapy to reduce the risk of heart attacks and strokes, and to lower blood glucose levels as close to "normal" as possible in patients with type 2 diabetes. Both of these recommendations now appear to have done much more harm than good. Patients' interests would have been better served if at least one guideline group had had the courage to jump off the bandwagon.