Figure 1. Participant Flow.

GP indicates general practitioner.

^aThe trial captured all eligible high-requesting GPs and practices. The median practice size was 1 (IQR, 1-2) for all groups. The 2666 randomized clusters are more than the number of practices reported in the statistical analysis plan (n = 2271) and include 395 practices randomized more than once due to an address classification administrative error that occurred in July 2019, prior to randomization, and that was detected during the data cleaning. See text and eAppendix 3 in Supplement 2 for details.

^bPractices were excluded if all GPs from the practice were excluded. A patient consultation was defined as professional attendance by a GP for which benefits are paid under the Australian Medicare Benefits Schedule.

^cGeneral practitioners were excluded from the per-protocol analysis if they (1) had their audit and feedback reports returned undelivered; (2) were allocated to receive audit and feedback on a second occasion but requested not to receive a second report (and were not mailed the second report); (3) were allocated to receive audit and feedback on a second occasion but did not make any musculoskeletal imaging requests during the audit period of November 8, 2019, to March 7, 2020; or (4) were allocated to receive audit and feedback on a second occasion but had fewer than 333 patient consultations during the 4-month audit period of November 8, 2019, to March 7, 2020, so calculating their percentile for rate of imaging requests was not reliable and therefore it was not reported on the second occasion.