Abstract
<title>Abstract</title> <p> <bold>Background:</bold> The COVID-19 pandemic altered healthcare utilization and environmental exposures relevant to COPD exacerbations. This study examined temporal trends in COPD exacerbations before and after pandemic onset and whether changes differed across demographic and social risk subgroups in a diverse urban population. <bold>Methods:</bold> In this retrospective cohort study, electronic medical record data were analyzed for 45,762 patients with COPD in the Montefiore Health System from March 2018 through February 2025. Monthly exacerbation rates were assessed using interrupted time series analysis. A difference-in-differences Poisson regression quantified differential changes between pre- and post-pandemic periods across subgroups defined by sex, race and ethnicity, insurance, neighborhood income, and documented unmet social needs. <bold>Results:</bold> At pandemic onset, COPD exacerbation rates declined immediately by 44% relative to expected levels. Post-pandemic rates remained 31.8% below counterfactual projections. No significant heterogeneity was observed by sex, race and ethnicity, or insurance. In contrast, patients with at least one documented unmet social need had the greatest relative increase in post-pandemic rates compared with those without unmet needs (DiD IRR, 1.32; 95% CI, 1.07-1.62), and patients in the third income quartile had higher relative increases than the highest quartile (DiD IRR, 1.26; 95% CI, 1.04-1.52). Exacerbation burden remained higher among Medicaid (IRR, 1.54) and Medicare (IRR, 1.80) beneficiaries than among privately insured patients. Sensitivity analyses were largely consistent. <bold>Conclusion:</bold> The COVID-19 pandemic was associated with a sustained reduction in COPD exacerbation rates that remained below pre-pandemic levels five years after pandemic onset. However, post-pandemic recovery was uneven, with widening disparities among patients in the third income quartile, those insured through Medicaid or Medicare, and those with documented unmet social needs, while racial and ethnic disparities remained relatively stable. These findings underscore the need for equity-focused interventions that address socioeconomic and insurance-related barriers to reduce exacerbation disparities in diverse urban populations. </p>