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 .