Impact of a multifaceted intervention to improve antibiotic prescribing: a pragmatic cluster-randomised controlled trial

Abstract

OBJECTIVES: This study sought to assess the effectiveness and return on investment (ROI) of a multifaceted intervention aimed at improving antibiotic prescribing for acute respiratory infections in primary care. DESIGN: Large-sized, two-arm, open-label, pragmatic, cluster-randomised controlled trial. SETTING: All primary care physicians working for the Spanish National Health Service (NHS) in Galicia (region in north-west Spain). PARTICIPANTS: The seven spatial clusters were distributed by unequal randomisation (3:4) of the intervention and control groups. A total of 1217 physicians (1.30 million patients) were recruited from intervention clusters and 1393 physicians (1.46 million patients) from control clusters. INTERVENTIONS: One-hour educational outreach visits tailored to training needs identified in a previous study; an online course integrated in practice accreditation; and a clinical decision support system. MAIN OUTCOME MEASURES: Changes in the ESAC (European Surveillance of Antimicrobial Consumption) quality indicators for outpatient antibiotic use. We used generalised linear mixed and conducted a ROI analysis to ascertain the overall cost savings. RESULTS: Median follow-up was 19 months. The adjusted effect on overall antibiotic prescribing attributable to the intervention was - 4.2% (95% CI: - 5.3% to - 3.2%), with this being more pronounced for penicillins - 6.5 (95% CI: - 7.9% to - 5.2%) and for the ratio of consumption of broad- to narrow-spectrum penicillins, cephalosporins, and macrolides - 9.0% (95% CI: - 14.0 to - 4.1%). The cost of the intervention was euro87 per physician. Direct savings per physician attributable to the reduction in antibiotic prescriptions was euro311 for the NHS and euro573 for patient contributions, with an ROI of euro2.57 and euro5.59 respectively. CONCLUSIONS: Interventions designed on the basis of gaps in physicians' knowledge of and attitudes to misprescription can improve antibiotic prescribing and yield important direct cost savings. TRIAL REGISTRATION: Current Controlled Trials ISRCTN24158380 . Registered 5 February 2009.