Cost-Effectiveness of IMPRovE: A Multicomponent Intervention to Increase Adherence to Guideline Recommendations for the Diagnosis and Management of Work-Related Mental Health Conditions in General Practice.

PURPOSE: To evaluate the cost and cost-effectiveness of a multicomponent intervention to increase general practitioners' (GPs) adherence to guideline recommendations for diagnosis and management of work-related mental health conditions (the Guideline). METHODS: Economic evaluation from Australian health system and societal perspectives based on data from a pragmatic hybrid III parallel cluster randomised controlled trial (IMPRovE) that ran from December 2020 to December 2022. RESULTS: The IMPRovE intervention generated a statistically significant improvement in GP adherence scores of 0.98 on 0 to 9 scale (95%CI: 0.38 to 1.58). We found no evidence for a significant between-group difference in total quality-adjusted life days (QALDs) per patient to trial-end (adjusted mean difference: -1.9, 95%CI: -24.2 to 20.3), productivity gains per patient to trial-end (adjusted mean difference: $5,818, 95%CI: -$12,346 to $23,982), or total health sector costs per patient to trial-end (adjusted mean difference: -$2,703, 95%CI: -$6,025 to $620). Under conservative assumptions, we find a significant between-group difference in total health sector cost per GP (adjusted mean difference: -$14,278, 95%CI: -$21,358, -$7,198). For improving GP adherence to the Guideline, we can be 95% confident that the IMPRovE intervention is more cost-effective than waitlist control from a health system perspective (when we set aside productivity gains). This remains the case even when improvements in GP adherence carry zero value. CONCLUSION: The IMPRovE intervention is likely to be more cost-effective than waitlist control for increasing GP adherence to Guideline recommendations. We were unable to draw strong conclusions regarding the cost-effectiveness of the IMPRovE intervention for improving patient outcomes. TRIAL REGISTRATION: ACTRN12620001163998, November 2020.