Exploration of the methodological quality and clinical usefulness of a cross-sectional sample of published guidance about exercise training and physical activity for the secondary prevention of coronary heart disease

Background: Clinicians are encouraged to use guidelines to assist in providing evidence-based secondary prevention to patients with coronary heart disease. However, the expanding number of publications providing guidance about exercise training may confuse cardiac rehabilitation clinicians. We therefore sought to explore the number, scope, publication characteristics, methodological quality, and clinical usefulness of published exercise-based cardiac rehabilitation guidance. Methods: We included publications recommending physical activity, exercise or cardiac rehabilitation for patients with coronary heart disease. These included systematically developed clinical practice guidelines, as well as other publications intended to support clinician decision making, such as position papers or consensus statements. Publications were obtained via electronic searches of preventive cardiology societies, guideline databases and PubMed, to November 2016. Publication characteristics were extracted, and two independent assessors evaluated quality using the 23-item Appraisal of Guidelines Research and Evaluation II (AGREE) tool. Results: Fifty-four international publications from 1994 to 2016 were identified. Most were found on preventive cardiology association websites (n = 35; 65%) and were freely accessible (n = 50; 93%). Thirty (56%) publications contained only broad recommendations for physical activity and cardiac rehabilitation referral, while 24 (44%) contained the necessary detailed exercise training recommendations. Many were labelled as "guidelines", however publications with other titles (e.g. scientific statements) were common (n = 24; 44%). This latter group of publications contained a significantly greater proportion of detailed exercise training recommendations than clinical guidelines (p = 0.017). Wide variation in quality also existed, with `applicability' the worst scoring AGREE II domain for clinical guidelines (mean score 53%) and `rigour of development' rated lowest for other guidance types (mean score 33%). Conclusions: While a large number of guidance documents provide recommendations for exercise-based cardiac rehabilitation, most have limitations in either methodological quality or clinical usefulness. The lack of rigorously developed guidelines which also contain necessary detail about exercise training remains a substantial problem for clinicians.