Case-mix-adjusted benchmarking of musculoskeletal outcomes and opioid prescribing in English primary care: a prospective cohort study

Objectives

To quantify provider-level variation in musculoskeletal (MSK) health outcomes, consultation experience and opioid prescribing in general practice using a validated case-mix-adjustment model, and to evaluate the feasibility of applying Achievable Benchmark of Care (ABC) and funnel plots to derive performance benchmarks.

Design

Prospective observational cohort study.

Setting

30 general practices across 13 primary care networks within a defined geographical region in England, UK (primary care).

Participants

1875 adults aged ≥18 years consulting general practice with non-inflammatory MSK pain between September 2021 and July 2022 who consented to data linkage. Of these, 1317 (70%) completed 3-month follow-up. Patients with inflammatory arthritis were excluded.

Interventions

None.

Primary and secondary outcome measures

Primary outcome was 3-month change in Musculoskeletal Health Questionnaire (MSK-HQ; range 0–56, higher scores better) score. Secondary outcomes were patient-reported poor consultation experience and opioid prescribing within 14 days of consultation. Multivariable case-mix models included demographic and clinical variables. Provider-level variation was assessed using funnel plots. ABC methodology defined achievable benchmarks based on top-performing providers.

Results

Mean unadjusted 3-month MSK-HQ improvement was 4.9 points. After case-mix-adjustment, the weighted mean improvement was 4.8 points, with provider-level adjusted gains ranging from 3.0 to 5.7 points. ABC benchmarks were 5.7 points for MSK-HQ improvement, 4.4% for poor experience and 19.6% for opioid prescribing. Case-mix-adjustment altered provider rankings compared with crude analyses. Funnel plots identified two providers exceeding the 95% control limit for opioid prescribing; no outliers were observed for MSK-HQ.

Conclusions

Case-mix-adjusted benchmarking of MSK care in general practice is feasible: combining case-mix models, ABC benchmarks and funnel plots offers a transparent framework for provider comparison. The low baseline response rate, which varied between networks, means the variation observed should be interpreted cautiously rather than as an assessment of individual providers.

Trial registration number

ISRCTN18132064.