Association between asthma/chronic obstructive pulmonary disease overlap syndrome and healthcare utilization among the US adult population.

Asthma/chronic obstructive pulmonary disease (COPD) overlap (ACO) is a recently described phenomenon defined as the coexistence of both asthma and COPD. Both asthma and COPD are known to result in increased emergency department (ED) visits and hospitalizations, but it is unclear how the ACO population utilizes these same healthcare resources. The objective of this study was to compare healthcare utilization in the ACO population versus the general population, the asthma population and the COPD population. We conducted a pooled cross-sectional statistical analysis using the 2012-2015 National Health Interview Survey (NHIS) data. We focused on adults 18 years of age and older and excluded pregnant women. We employed an adjusted logit regression model, where the primary outcomes were dichotomous indicators on healthcare utilizations including ED visits and hospital stays. A key covariate was a four-category variable: 1) no asthma or COPD; 2) asthma only; 3) COPD only; and 4) ACO. Other covariates included age, sex, race, education level, marital status, household income level, medical insurance status, smoking status, body mass index (BMI) category, region, year and comorbidities (cancer, diabetes, hypertension, coronary heart disease and ulcer). Adults with ACO were 134%, 53% and 21% more likely to have ED visits than the general population, asthma group and COPD group, respectively. For hospital stay, the ACO group was 120% and 86% more likely to be hospitalized than the general population and the asthma group respectively. In addition, adults with ACO were 61% and 130% more likely to have asthma exacerbations and asthma-related ED visits than the asthma group. ACO is a considerable risk factor for healthcare utilization versus the general population, the asthma population and the COPD population. Future focus should be placed on the ACO population to identify ways to reduce their healthcare utilization.