Economic burden of psoriasis compared to the general population and stratified by disease severity

Objective: To evaluate health care utilization and costs for patients with psoriasis vs. the general population and by psoriasis severity. Research design and methods: Claims data were analyzed for adult patients with >= 1 diagnosis of psoriasis and continuous enrollment during the year of 2003 (case sample). A control sample was matched 2: 1 on baseline demographic characteristics to the case sample. Case samples were further stratified by psoriasis severity based on treatment patterns. Outcomes were compared descriptively and by a multivariate two-part model to evaluate differences between the case vs. control groups and by psoriasis severity. Main outcome measures: Outcomes included health care resource utilization and health care costs. Results: A total of 56,528 patients with psoriasis met the inclusion criteria. Patients with psoriasis had significantly greater total health care resource utilization, total medical resource utilization, and total drug utilization vs. the control sample (p < 0.0001). Compared with control patients, patients with psoriasis had significantly greater total health care costs ($5529 vs. $3509), including greater medical costs ($3925 vs. $2687) and drug costs ($1604 vs. $822; all p < 0.0001). Patients with moderate to severe psoriasis (n=5248) had greater total health care costs vs. patients with mild psoriasis (n=51,280) ($10,593 vs. $5011), including greater medical costs ($5854 vs. $3728) and drug costs ($4738 vs. $1283; all p < 0.0001). Multivariate analyses confirmed the increased utilization and costs in all comparisons. Limitations: The study limitations included limited generalizability of the findings beyond the study population, classification of disease severity based on treatment instead of clinical measures, and exclusion of out-of-pocket costs and indirect costs in the study. Conclusions: Patients with psoriasis incur greater health care resource utilization and costs compared with the general population. Psoriasis severity is positively associated with increased health care resource utilization and costs.