Drivers of Healthcare Costs Among the Costliest Patients With Psoriasis Over Three Years in a United States Health Plan

July 2017 | Volume 16 | Issue 7 | Original Article | 651 | Copyright © July 2017


April W. Armstrong MD MPH,a Yang Zhao PhD,b Vivian Herrera PhD,b Yunfeng Li PhD,b Tim Bancroft PhD,e Michael Hull MS,c and Aylin Altan PhDd

aUniversity of Southern California, Los Angeles, CA bHealth Economics and Outcomes Research, Novartis Pharmaceuticals Corporation, East Hanover, NJ cHealth Economics and Outcomes Research, Optum, Eden Prairie, MN dOptum Labs, Eden Prairie, MN

Abstract

OBJECTIVE: To compare patients with psoriasis by cost level over 3 years.

METHODS: Psoriasis patients in a large US health plan in 2011-2013 were identified. Four groups were created by healthcare costs excluding biologics: patients having top 10% of costs in all 3 years (Top), top 10% in 2 of 3 years (High), bottom 90% in 2 of 3 years (Medium), and bottom 90% in all 3 years (Bottom). Comorbidities, utilization, and costs between groups were compared.

RESULTS: The study included 18,653 patients: 514 (3%), 805 (4%), 2,443 (13%), and 14,891 (80%) patients in the Top, High, Medium, and Bottom groups, respectively. Significantly more patients in the Top vs Bottom group had diabetes (31.1% vs 9.4%), cardiovascular disease (26.5% vs 4.3%), psoriatic arthritis (25.7% vs 10.7%), depression (27.8% vs 6.9%), and anxiety (22.0% vs 7.9%) in 2011 (all P less than 0.05). Patients in the Top group had more unique 2011 prescriptions (17.7 vs 6.6; P less than 0.001) than the Bottom group, but similar biologic use (22.4% vs 21.6%). Patients in the Top, High, Medium, and Bottom groups had mean 2011 total costs of $68,913, $40,575, $24,292, and $8,815, and contributed to 14%, 13%, 23%, and 51% of the overall costs, respectively. Mean total costs increased 14-18% over time for all groups. Although mean 2011 total costs for patients in the Top group were 7.8 times of those in the Bottom group, psoriasis-related costs were less disparate ($8,716 vs $4,541). Compared with patients in the Bottom group, those in the Top group were more likely to have any 2011 hospitalization (36.8% vs 2.6%; psoriasis-related: 11.1% vs 0.7%) or emergency visit (50.8% vs 20.8%; psoriasis-related: 3.9% vs 1.0%).

CONCLUSION: The costliest patients with psoriasis had significantly higher prevalence of comorbidities, prescription fills, inpatient and emergency utilization, but not biologic medication use or biologic costs.

J Drugs Dermatol. 2017;16(7):651-658.

INTRODUCTION

Psoriasis is a prevalent, chronic, debilitating, immune-mediated condition, affecting about 3.2% of the population (7.5 million) in the United States (US).1 Psoriasis is significantly associated with cardiovascular conditions (hypertension, dyslipidemia, myocardial infarction, coronary artery disease), and has been shown to be an independent risk factor for developing cardiovascular disease and metabolic conditions (diabetes mellitus, obesity, and metabolic syndrome).2-13 Because patients often experience psychosocial stigma and impaired health-related quality of life (HRQOL), they also have increased rates of anxiety and depression.14-17 Additionally, psoriasis imposes a substantial cost to healthcare systems as well as individuals.18-19 Psoriasis has traditionally been treated with topical corticosteroids, phototherapy, and systemic medications, such as corticosteroids, and methotrexate.20 Treatment with biologic medications has become increasingly common since 2002. Biologics incur significantly higher costs relative to other treatment options, and over one-third of patients treated with existing biologics experience dose escalation.21 Some studies have found biologic medications to be a substantial (50-67%) component of medical costs.22-24 However, in a previous study by this group, the use and costs attributable to biologic medications did not differ significantly between patients incurring the highest 10% of total costs excluding biologics and those having the bottom 90% of costs. No known studies have examined the characteristics of patients who are consistently the most costly over time; such information can help both physicians and payers make informed decisions in psoriasis management. The objective of this study was to use a large US healthcare database to examine resource utilization, costs, and demographic and clinical characteristics among US psoriasis patients whose healthcare services were consistently highest over a 3-year period.

METHODS

Data Source and Sample

This retrospective study utilized administrative healthcare claims data from the Optum Research Database (ORD), including