Risk factors for asthma-related healthcare use: longitudinal analysis using the NHI claims database in a Korean asthma cohort.

Abstract

BACKGROUND: Though insurance claims data are useful for researching asthma, they

have important limitations, such as a diagnostic inaccuracy and a lack of

clinical information. To overcome these drawbacks, we used the novel method by

merging the clinical data from our asthma cohort with the National Health

Insurance (NHI) claims data. METHODS AND RESULTS: Longitudinal analysis of

asthma-related healthcare use from the NHI claims database, merged with data of

736 patients registered in a Korean asthma cohort, was conducted for three

consecutive years from registration of the cohort. Asthma-related asthma

healthcare referred to outpatient and emergency department visits,

hospitalizations, and the use of systemic corticosteroids. Univariate and

multivariate logistic regression analysis was used to evaluate risk factors for

asthma-related healthcare. Over three years after enrollment, many patients

changed from tertiary to primary/secondary hospitals with a lack of maintenance

of inhaled corticosteroid-based controllers. An independent risk factor for

emergency visits was a previous history of asthma exacerbation. In

hospitalizations, old age and Asthma Control Test (ACT) score variability were

independent risk factors. An independent risk factor for per person cumulative

duration of systemic corticosteroids was the FEV1 (Forced expiratory volume in

one second)%. The use of systemic corticosteroids was independently associated

with being female, the FEV1%, and ACT score variability. CONCLUSION: We found

that old age, being female, long-standing asthma, a low FEV1%, asthma

brittleness, asthma drug compliance, and a history of asthma exacerbation were

independent risk factors for increased asthma-related healthcare use in Korea.