A comprehensive study of the direct and indirect costs of adult asthma.

BACKGROUND Asthma is a common and costly health condition, but most estimates of its economic effect have relied on secondary sources with limited condition-specific detail. OBJECTIVE We sought to estimate the magnitude of direct and indirect costs of adult asthma from the perspective of society. METHODS We used cross-sectional survey data from an ongoing community-based panel study of 401 adults with asthma originally derived from random samples of northern California pulmonologists, allergist-immunologists, and family practitioners to assess health care use for asthma, to assess purchase of items to assist with asthma care, and to measure work and other productivity losses. Unit costs derived from public-use and proprietary data sources were then assigned to the survey items. RESULTS Total per-person annual costs of asthma averaged $4912 US dollars, with direct and indirect costs accounting for $3180 US dollars (65%) and $1732 US dollars (35%), respectively. The largest components within direct costs were pharmaceuticals ($1605 US dollars [50%]), hospital admissions ($463 US dollars[15%]), and non-emergency department ambulatory visits ($342 US dollars [11%]). Within indirect costs, total cessation of work accounted for $1062 US dollars (61%), and the loss of entire work days among those remaining employed accounted for another $486 US dollars (28%). Total per-person costs were $2646, $4530, and $12,813 US dollars for persons self-reporting mild, moderate, and severe asthma, respectively (P <.0001, 1-way ANOVA). CONCLUSION Asthma-related costs are substantial and are driven largely by pharmaceuticals and work loss.