Costs of asthma among US working adults.

Objectives: To evaluate the effect of asthma on direct and indirect costs among US working adults.

Study Design: A case-control retrospective analysis was conducted. Data between January 1, 2003, and December 31, 2006, among patients aged 18 to 64 years with vs without asthma were extracted from MarketScan Research Databases. Patients with chronic obstructive pulmonary disease or emphysema were excluded, and all patients were required to have 12-month continuous enrollment before and after the index date. Outcomes included direct medical costs, the number of absence days, the number of short-term disability days, and associated indirect costs.

Methods: Patients with asthma were propensity score-matched to patients without asthma using nearest neighbor 1:1 with caliper. Subsequent multivariate analysis was conducted on matched samples to examine the marginal effect of asthma on direct and indirect costs.

Results: A total of 13,379 patients with asthma were propensity score-matched to 13,379 patients without asthma; in each cohort, 3453 patients had absence eligibility, and 8497 patients had short-term disability eligibility. Direct costs for patients with asthma were $3762, and indirect costs were $4572. Compared with the matched cohort without asthma, patients with asthma had $1785 higher direct medical expenditures (P <.001). Incremental indirect costs were $191 for absenteeism (P = .007) and $172 for short-term disability (P<.001).

Conclusions: Compared with patients without asthma, patients with asthma experience significantly higher direct medical costs and, although modest, significantly higher work loss. Treatments or interventions that prevent or reduce asthma symptoms may have a beneficial effect on medical costs and work absenteeism.