Examining the Relationship Between Depression and Asthma Exacerbations in a Prospective Follow-Up Study

BACKGROUND: Although depression has been linked with asthma, its relationship with asthma exacerbations, including emergency department (ED) visits and oral steroid (OS) use, has not been well documented. The aim is to investigate whether depression increases exacerbations among patients with asthma. METHOD: The study included 568 participants with asthma who were between 18 and 56 years old, were taking an inhaled corticosteroid, and participated in baseline and follow-up surveys. Surveys and medical records from a large, health system were collected as part of the Adherence Feedback for Improving Respiratory Medication Use trial. Number of ED visits and OS prescription fills for asthma were calculated for 12-month periods before and after the follow-up survey. Depression was measured using a standardized two-item instrument. Negative binomial regression and modified proportional hazards models were used. RESULTS: Among patients with asthma, those who had depression (n = 187; 32.9%) were at increased risk for an asthma-related ED visit (adjusted relative risk = 1.96, 95% confidence interval [CI] = 1.02-3.75), but not an OS fill (adjusted relative risk = 0.98; 95% CI = 0.72-1.32). Participants with depression and asthma who received psychiatric treatment via antidepressant medication (n = 126; 22.2%) or psychotherapy (n = 39; 6.9%) were more likely to have an ED visit (medication hazard ratio = 2.09, 95% CI = 1.35-3.25; psychotherapy hazard ratio = 2.07, 95% CI = 1.38-3.22). CONCLUSIONS: This study suggests a temporal relationship between depression and asthma-related ED visits. Research and practice must consider the importance of these comorbid conditions. Trial Registration ClinicalTrials.gov identifier: NCT00459368.