The effect of comorbid anxiety and depressive disorders on health care utilization and costs among adolescents with asthma.

OBJECTIVE: To assess whether youth with asthma and comorbid anxiety and depressive disorders have higher health care utilization and costs than youth with asthma alone.
METHODS: A telephone survey was conducted among 767 adolescents (aged 11 to 17 years) with asthma. Diagnostic and Statistical Manual-4th Version (DSM-IV) anxiety and depressive disorders were assessed via the Diagnostic Interview Schedule for Children. Health care utilization and costs in the 12 months pre- and 6 months post-interview were obtained from computerized health plan records. Multivariate analyses were used to determine the impact of comorbid depression and anxiety on medical utilization and costs.
RESULTS: Unadjusted analyses showed that compared to youth with asthma alone, youth with comorbid anxiety/depressive disorders had more primary care visits, emergency department visits, outpatient mental health specialty visits, other outpatient visits and pharmacy fills. After controlling for asthma severity and covariates, total health care costs were approximately 51% higher for youth with depression with or without an anxiety disorder but not for youth with an anxiety disorder alone. Most of the increase in health care costs was attributable to nonasthma and non-mental health-related increases in primary care and laboratory/radiology expenditures.
CONCLUSIONS: Youth with asthma and comorbid depressive disorders have significantly higher health care utilization and costs. Most of these costs are due to increases in non-mental health and nonasthma expenses. Further study is warranted to evaluate whether improved mental health treatment and resulting increases in mental health costs would be balanced by savings in medical costs.