At-risk registers integrated into primary care to stop asthma crises in the UK: cluster randomised controlled trial with economic evaluation

BACKGROUND: A regional trial indicated that implementing at-risk asthma registers in primary care could reduce hospital admissions. This national study assessed whether the intervention lowered asthma crisis events. METHODS: This cluster randomised trial involved 275 UK primary care practices. The intervention included identifying at-risk patients, staff training, a clinical decision support system alerting practice staff to patients' at-risk status to facilitate prompt and opportunistic care, and ongoing support. Control practices continued with standard care. Patients (n=10 945) were included if identified as at-risk, unless they declined data sharing. Routine data linked across care settings captured asthma-related crisis events (hospitalisations, accident and emergency visits or death), asthma care indicators and healthcare costs over 12 months. RESULTS: Complete data were available from 185 practices (6207 patients), with exclusions mainly due to record linkage issues. Crisis events occurred in 7.2% of control versus 6.3% of intervention patients (OR 0.82, 95% CI 0.66 to 1.03, p=0.09). Individual components of the composite outcome showed similar, non-significant reductions. The use of systemic corticosteroids for asthma attacks had an OR of 1.18 (95% CI 0.99 to 1.41, p=0.07); personalised asthma action plans, OR 1.05 (95% CI 0.78 to 1.42, p=0.74); inhaler technique assessments, OR 1.13 (95% CI 0.93 to 1.38, p=0.23). Economic analysis estimated the intervention was cost-effective, with average annual National Health Service costs £306 lower in the intervention group. CONCLUSION: This trial did not provide sufficient evidence to show that the establishment and integration of at-risk registers for asthma in primary care reduces asthma-related crisis events for people with at-risk asthma, but there was some indication of benefit. TRIAL REGISTRATION NUMBER: ISRCTN95472706.