BETA and the Department of Health ran a trial to test the impact of personalised letters from Australia's Chief Medical Officer to high-prescribing GPs prompting them to consider reducing antibiotic prescribing where appropriate and safe. The most effective letter, with a graph comparing GP's prescribing behaviour to their peers, reduced antibiotic prescription by 12 per cent over six months.
Intervention start and end date: Tuesday, 6 June 2017 to Friday, 30 June 2017
BETA ethics pre-registration number: BETA-2017-012
Experimental design: Cluster randomised controlled trial with data collected monthly until the end of the intervention period (12-months).
Randomisation at the practice level. Practices matched into quintuplets using an optimal greedy algorithm based on: number of GPs in the cluster, cluster average prescription rate over the previous 12 months and the cluster SEIFA score (a measure of socioeconomic advantage/disadvantage for the geographic area containing the practice).
Intervention(s): Active interventions include sending letters about antimicrobial resistance and antibiotic prescriptions to GPs.
Control condition: No letter.
The number of antibiotic prescriptions per 1000 GP visits, measured monthly for 12 months.
Expected sample size: Planned number of clusters: 3,198. Approximately 640 clusters in each of 5 groups. Each treatment arm will contain approximately 1,330 individual GPs.
Registration number: BETA-2017-012