Not all guidelines are created equal

A recent CMAJ editorial drew attention to the potential for conflicts of interest to influence the development of clinical guidelines.1 While we share your concerns, we wanted to register our disagreement with the CMAJ editorialist's conclusion that the only way to reduce potential conflicts of interest is to mandate that guideline panels consist only of non-experts. We believe strongly that clinical expertise in a particular area is necessary to properly interpret evidence related to that area.

We believe that the best solution to the dilemma raised by your editorialist is to ensure that guideline panels develop a transparent system of checks and balances that ensures both the integrity of the process and the quality of the recommendations made. To that end, we would like to point out that the hypertension recommendations produced by the CHEP are developed annually by experts from a variety of disciplines, none of whom are paid for their CHEP activities, and the following steps are taken to minimize potential biases:

1. An independent steering committee (consisting of representatives of the Canadian Hypertension Society, Blood Pressure Canada, the Heart and Stroke Foundation of Canada, the Public Health Agency of Canada, the College of Family Physicians of Canada, the Canadian Council of Cardiovascular Nurses, and the Canadian Pharmacists Association) oversee the process.

2. Clinical experts work with a Cochrane librarian to systematically identify and review the evidence in each topic area, and a central review committee of 4 methodologists reviews all of the evidence and recommendations prepared by these clinical experts. While clinical experts may receive funding from the pharmaceutical industry for advisory panels, consultantships, or speakers bureaus, the members of the central review committee explicitly do not.

3. All draft recommendations that are developed by the clinical experts for that topic and the central review committee to meet pre-specified levels of evidence are presented to and debated by the Recommendations Task Force of CHEP (44 unpaid volunteers with academic and clinical expertise in hypertension).

4. The potential conflicts of interest of all members are identified, disclosed in writing and distributed at the consensus conference, and members with significant conflicts of interest are asked to abstain from votes on recommendations related to their potential conflicts.

5. Only those draft recommendations supported by 70% or more of the Recommendations Task Force members are subsequently accepted.

6. Although CHEP does receive funding from multiple sources to cover the costs of developing and disseminating the guidelines, the largest single financial sponsor of CHEP activities in 2005 was the Public Health Agency of Canada.

Although the CMAJ editorial suggests that more expensive antihypertensive therapies have been recommended over less expensive alternatives in Canada, we feel it important to point out that diuretics have been recommended as first-line drug therapy for hypertension in every iteration of the Canadian national hypertension recommendations over the past three decades (including a period when international guideline panels had recommended against them). Indeed, in our listing of appropriate choices for first-line therapy, thiazide diuretics are the only drug class assigned a grade A recommendation.2 Further, the percent increase in prescriptions for diuretics has increased dramatically and more than the increases for angiotensin-converting enzyme inhibitors or calcium channel blockers since the CHEP program started.3