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.
Outcome(s)
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