Quantifying sustained health system benefits of primary care-based integrated disease management for COPD: a 6-year interrupted time series study.

BACKGROUND: Severe exacerbation of chronic obstructive pulmonary disease (COPD) is a trajectory-changing life event for patients and a major contributor to health system costs. This study evaluates the real-world impact of a primary care, integrated disease management (IDM) programme on acute health service utilisation (HSU) in the Canadian health system. METHODS: Interrupted time series analysis using retrospective health administrative data, comparing monthly HSU event rates 3 years prior to and 3 years following the implementation of COPD IDM. Primary outcomes were COPD-related hospitalisation and emergency department (ED) visits. Secondary outcomes included hospital bed days and all-cause HSU. RESULTS: There were 2451 participants. COPD-related and all-cause HSU rates increased in the 3 years prior to IDM implementation. With implementation, there was an immediate decrease (month 1) in COPD-related hospitalisation and ED visit rates of -4.6 (95% CI: -7.76 to -1.39) and -6.2 (95% CI: -11.88, -0.48) per 1000 participants per month, respectively, compared with the counterfactual control group. After 12 months, COPD-related hospitalisation rates decreased: -9.1 events per 1000 participants per month (95% CI: -12.72, -5.44) and ED visits -19.0 (95% CI: -25.50, -12.46). This difference nearly doubled by 36 months. All-cause HSU also demonstrated rate reductions at 12 months, hospitalisation was -10.2 events per 1000 participants per month (95% CI: -15.79, -4.44) and ED visits were -30.4 (95% CI: -41.95, -18.78). CONCLUSIONS: Implementation of COPD IDM in a primary care setting was associated with a changed trajectory of COPD-related and all-cause HSU from an increasing year-on-year trend to sustained long-term reductions. This highlights a substantial real-world opportunity that may improve health system performance and patient outcomes.