Effect of an Individualized Audit and Feedback Intervention on Rates of Musculoskeletal Diagnostic Imaging Requests by Australian General Practitioners: A Randomized Clinical Trial

Abstract

Importance: Audit and feedback can improve professional practice, but few trials have evaluated its effectiveness in reducing potential overuse of musculoskeletal diagnostic imaging in general practice.

Objective: To evaluate the effectiveness of audit and feedback for reducing musculoskeletal imaging by high-requesting Australian general practitioners (GPs).

Design, setting, and participants: This factorial cluster-randomized clinical trial included 2271 general practices with at least 1 GP who was in the top 20% of referrers for 11 imaging tests (of the lumbosacral or cervical spine, shoulder, hip, knee, and ankle/hind foot) and for at least 4 individual tests between January and December 2018. Only high-requesting GPs within participating practices were included. The trial was conducted between November 2019 and May 2021, with final follow-up on May 8, 2021.

Interventions: Eligible practices were randomized in a 1:1:1:1:1 ratio to 1 of 4 different individualized written audit and feedback interventions (n = 3055 GPs) that varied factorially by (1) frequency of feedback (once vs twice) and (2) visual display (standard vs enhanced display highlighting highly requested tests) or to a control condition of no intervention (n = 764 GPs). Participants were not masked.

Main outcomes and measures: The primary outcome was the overall rate of requests for the 11 targeted imaging tests per 1000 patient consultations over 12 months, assessed using routinely collected administrative data. Primary analyses included all randomized GPs who had at least 1 patient consultation during the study period and were performed by statisticians masked to group allocation.

Results: A total of 3819 high-requesting GPs from 2271 practices were randomized, and 3660 GPs (95.8%; n = 727 control, n = 2933 intervention) were included in the primary analysis. Audit and feedback led to a statistically significant reduction in the overall rate of imaging requests per 1000 consultations compared with control over 12 months (adjusted mean, 27.7 [95% CI, 27.5-28.0] vs 30.4 [95% CI, 29.8-30.9], respectively; adjusted mean difference, -2.66 [95% CI, -3.24 to -2.07]; P < .001).

Conclusions and relevance: Among Australian general practitioners known to frequently request musculoskeletal diagnostic imaging, an individualized audit and feedback intervention, compared with no intervention, significantly decreased the rate of targeted musculoskeletal imaging tests ordered over 12 months.

Trial registration: ANZCTR Identifier: ACTRN12619001503112.

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.

Figure 2.. Overall Rates of Musculoskeletal Diagnostic Imaging Requests and Changes in Percentile Rank Over Time

Corresponding model-based mean cumulative rates with standard deviations from baseline to 6, 12, and 18 months are reported in Table 2. See eFigure 1 in Supplement 2 for rates with 95% confidence intervals.