Regional Differences in Hospitalizations among Patients Admitted with Chronic Obstructive Pulmonary Disease.

Objective: Extreme temperatures negatively impact pulmonary function. This study explored whether the variability in ambient temperatures across disparate geographic regions in the United States was associated with differences in hospital outcomes for patients admitted with chronic obstructive pulmonary disease (COPD).

Methods: Using the 2016-2019 National Inpatient Sample database, we compared adults hospitalized with COPD in the US Northeast with those in the US South. We conducted multivariable regression analyses to study outcomes, including mortality, resource utilization, and posthospital discharge disposition.

Results: From 2016 to 2019, 463,830 (30.1%) patients were admitted with COPD in the Northeast and 1,078,930 (69.9%) in the South. The lowest hospitalization rates for COPD were observed in both regions during the hottest months (July and August). Those in the Northeast had higher adjusted odds of in-hospital mortality (adjusted odds ratio: 1.1 [95% confidence interval {CI} 1.0-1.2]; P = 0.03) and a lower likelihood of being discharged to home after the hospitalizations (adjusted odds ratio: 0.63 [95% CI 0.61-0.65]; P < 0.01]) compared with patients hospitalized in the South. Patients in the Northeast had longer hospital stays (adjusted mean difference: +0.19 days; 95% CI 0.13-0.25; P < 0.01) and incurred greater hospital charges compared with patients in the South (adjusted mean difference: $3728; 95% CI 1840-5616; P < 0.01).

Conclusions: Patients hospitalized with COPD in the Northeast had worse clinical outcomes and greater resource utilization than in the South. These findings, coupled with the higher admission rates during colder months, raise questions about the influence of colder ambient temperatures on COPD exacerbations.