Increased Prevalence of Psychiatric Disorders and Health Care-Associated Costs Among Patients With Moderate-to-Severe Psoriasis

August 2011 | Volume 10 | Issue 8 | Original Article | 843 | Copyright © August 2011


Abstract
Objective: To characterize the prevalence of psychiatric disorders in patients with moderate-to-severe psoriasis and compare health care costs between patients with and without psychiatric comorbidities.
Methods: In a retrospective, matched case-control study, data for services from nearly 75 health care plans in the United States (U.S.) were collected from PharMetrics Patient Centric Database using International Classification of Diseases, Ninth Revision Clinical Modification codes, identifying a total of 39,855 adults with moderate-to-severe psoriasis (n=7,971) and without (controls; n=31,884). Patients with psoriasis had at least one psoriasis health care claim and received at least one medical/prescription treatment claim within two consecutive years. Psychiatric comorbidities and treatments among patients and controls were determined by claims. Annual inpatient, outpatient, emergency room, and prescription costs for those with and without psoriasis and those with and without psychiatric disorders were compared.
Results: Patients had significantly higher prevalence of anxiety (6.9% versus 4.4%), depression (9.2% versus 5.3%), bipolar disorder (1.1% versus 0.5%), or delirium (0.3% versus 0.1%; P<0.05) than controls (others P<0.0001). Significantly higher proportions of patients with psoriasis received antidepressants (6.1% versus 0.9%), anxiolytics (5.0% versus 0.8%), or antipsychotics (5.9% versus 0.9%) compared with controls (each P<0.0001). Total health care costs for patients with psoriasis (US $11, 369.47) were significantly higher than for controls ($3,427.60; P<0.001). Psoriasis patients with psychiatric disorders had significantly higher health care costs ($17,637.66) than those without psychiatric disorders ($10,362.80; P<0.001).
Conclusion: The prevalence of psychiatric disorders is higher in patients with moderate-to-severe psoriasis than in controls. Annual health care costs are higher in psoriasis patients with psychiatric disorders than in those without psychiatric disorders.

J Drugs Dermatol. 2011;10(8):843-850.

INTRODUCTION

Psoriasis is a chronic, immune-mediated, inflammatory skin disease that affects approximately 3% of the population in the United States (U.S.),1 or 6.4 million people.2 Recently, more emphasis has been placed on the psychological and social impact of the disease, which has previously been primarily classified as a skin disorder.
The effect of psoriasis on individuals' health-related quality of life is significant,3-5 especially for those between 18 and 45 years of age, a time when many patients are highly involved in their professional careers, family responsibilities, and so lives.6 A survey of members of the National Psoriasis Foundation found that of the approximately 6,000 patients with severe psoriasis, 79 percent stated that psoriasis had a negative impact on their lives.5 The negative effect of psoriasis on quality of life is comparable to that reported by individuals with cancer, arthritis, hypertension, heart disease, diabetes and depression.7
Depression is a common comorbidity in patients with psoriasis. 4,8,9 Approximately 15 percent of individuals with psoriasis reported having depression,10 and in one study, approximately 34 percent had mild or moderate-to-severe depression, as