Economic and Comorbidity Burden Among Patients with Moderate-to-Severe Psoriasis

BACKGROUND: Previous studies demonstrated substantial economic and comorbidity burden associated with psoriasis (PsO) before biologics were available. Biologics have changed PsO treatment paradigms and potentially improved patient outcomes. There is a need to reassess the economic and comorbidity burden of PsO in the biologic era. OBJECTIVE: To compare the prevalence of comorbidities, health care resource utilization, and costs between moderate-to-severe PsO patients and demographically matched controls. METHODS: Adults aged 18-64 years with at least 2 PsO diagnoses (ICD-9-CM code 696.1) were identified in the OptumHealth Reporting and Insights claims database from January 2007 to March 2012. Moderate-to-severe PsO patients were identified as those receiving ≥ 1 systemic therapy or phototherapy during the 12-month study period following the index date (randomly selected date after the first PsO diagnosis). Controls were free of PsO and psoriatic arthritis (PsA) and were matched 1:1 with PsO patients on age, gender, and geographic region. All patients had at least 12 months of continuous enrollment after the index date. Selected comorbidities, medication use, all-cause health care utilization, and costs were compared between PsO patients and controls. Multivariate regression models were performed to examine the association between PsO and selected comorbidities, medication use, and health care costs and utilization, adjusting for demographics, index year, insurance type, and other comorbidities. Odds ratios (ORs) were reported for any medication use, hospitalization, emergency room visit, and outpatient visit, and incidence rate ratios (IRRs) were reported for the number of medications filled. Adjusted cost differences between PsO patient and controls were also estimated. RESULTS: A total of 5,492 matched pairs of moderate-to-severe PsO patients and controls were selected, with a mean age of 47.6 years and 55.5% of patients being male. PsO patients were significantly more likely to have most of the comorbidities examined, with the top 3 most common in both groups being hyperlipidemia (33.3% vs. 27.3%), hypertension (32.8% vs. 23.5%), and diabetes (15.8% vs. 9.7%). Compared with controls, PsO patients were more likely to have any medication filled (OR = 27.5) and had more distinct number of prescription medications (IRR = 2.1; both P < 0.01). PsO patients were more likely to have any inpatient admission (OR = 1.3), emergency room visit (OR = 1.3), and outpatient visit (OR = 29.3; all P < 0.01). PsO patients also incurred significantly higher total, pharmacy, and medical costs (adjusted annual costs differences: $18,960, $13,990, and $3,895 per patient, respectively; all P < 0.01) than controls. CONCLUSIONS: Compared with PsO- and PsA-free controls, moderate-to-severe PsO patients were more likely to have selected comorbidities and higher health care utilization and costs.