Cluster randomised controlled trial to compare three methods of promoting secondary prevention of coronary heart disease in primary
Authors: M. Moher
Journal: BMJ (2001)

<h3>Abstract</h3> <b>Objective:</b> To assess the effectiveness of three different methods of promoting secondary prevention of coronary heart disease in primary care. <b>Design:</b> Pragmatic, unblinded, cluster randomised controlled trial. <b>Setting:</b> Warwickshire. <b>Subjects:</b> 21 general practices received intervention; outcome measured in 1906 patients aged 55-75 years with established coronary heart disease. <b>Interventions:</b> Audit of notes with summary feedback to primary health care team (audit group); assistance with setting up a disease register and systematic recall of patients to general practitioner (GP recall group); assistance with setting up a disease register and systematic recall of patients to a nurse led clinic (nurse recall group). <b>Main outcome measures:</b> At 18 months9 follow up: adequate assessment (defined) of 3 risk factors (blood pressure, cholesterol, and smoking status); prescribing of hypotensive agents, lipid lowering drugs, and antiplatelet drugs; blood pressure, serum cholesterol level, and plasma cotinine levels. <b>Results:</b> Adequate assessment of all 3 risk factors was much more common in the nurse and GP recall groups (85%, 76%) than the audit group (52%). The advantage in the nurse recall compared with the audit group was 33% (95% confidence interval 19% to 46%); in the GP recall group compared with the audit group 23% (10% to 36%), and in the nurse recall group compared with the GP recall group 9% (−3% to 22%). However, these differences in assessment were not reflected in clinical outcomes. Mean blood pressure (148/80, 147/81, 148/81 mm Hg), total cholesterol (5.4, 5.5, 5.5 mmol/l), and cotinine levels (% probable smokers 17%, 16%, 19%) varied little between the nurse recall, GP recall, and audit groups respectively, as did prescribing of hypotensive and lipid lowering agents. Prescribing of antiplatelet drugs was higher in the nurse recall group (85%) than the GP recall or audit groups (80%, 74%). After adjustment for baseline levels, the advantage in the nurse recall group compared with the audit group was 10% (3% to 17%), in the nurse recall group compared with the GP recall group 8% (1% to 15%) and in the GP recall group compared with the audit group 2% (−6% to 10%). <b>Conclusions:</b> Setting up a register and recall system improved patient assessment at 18 months9 follow up but was not consistently better than audit alone in improving treatment or risk factor levels. Understanding the reasons for this is the key next step in improving the quality of care of patients with coronary heart disease. <h3>What is already known on this topic</h3> Effective preventive care of patients with any chronic disease requires planned and quality assured follow up on the basis of an up to date register Strategies for changing clinical practice in primary care have been of limited effectiveness <h3>What this study adds</h3> Setting up a coronary heart disease register for a practice substantially increases follow up and adequate assessment of patients at risk Improved assessment and follow up does not necessarily improve clinical outcome Follow up by nurses is as effective as, and may be more effective than, follow up by doctors Patients are being followed up and adequately assessed without the recommended preventive drugs being prescribed