Provision of social-norms feedback to general practices whose antibiotic prescribing is increasing : a national randomized controlled trial

Gold, N. and Ratajczak, M. and Sallis, A. and Saei, A. and Watson, R. and van Schaik, P. and Bowen, S. and Chadborn, T. (2022) Provision of social-norms feedback to general practices whose antibiotic prescribing is increasing : a national randomized controlled trial. Journal of Public Health, 30 (10). pp. 2351-2358. ISSN 1613-2238

Abstract

Aim: The Chief Medical Officer of England writes an annual social-norms-feedback letter to the highest antibiotic-prescribing GP practices. We investigated whether sending a social-norms-feedback letter to practices whose prescribing was increasing would reduce prescribing. Subject and methods: We conducted a two-armed randomised controlled trial amongst practices whose STAR-PU-adjusted prescribing was in the 20th–95th percentiles and had increased by > 4% year-on-year in the 2 previous financial years. Intervention practices received a letter on 1st March 2018 stating ‘The great majority (80%) of practices in England reduced or stabilised their antibiotic prescribing rates in 2016/17. However, your practice is in the minority that have increased their prescribing by more than 4%.’. Control practices received no letter. The primary outcome was the STAR-PU-adjusted rate of antibiotic prescribing in the months from March to September 2018. Results: We randomly assigned 930 practices; ten closed or merged pre-trial, leaving 920 practices — 448 in the intervention and 472 in the control. An autoregressive and moving average model of first order ARMA(1,1) correlation structure showed no effect of the intervention (β <−0.01, z = −0.50, p = 0.565). Prescribing reduced over time in both arms (β <−0.01, z = −36.36, p <0.001). Conclusions: A social-norms-feedback letter to practices whose prescribing was increasing did not decrease prescribing compared to no letter. Trial registration: NCT03582072.