INTRODUCTION
Psoriasis is a chronic inflammatory disease that affects more than 7.5 million people in the United States.1 Although psoriasis is most prevalent in whites (3.2%), African Americans often exhibit more extensive skin involvement, present with more severe variants of psoriasis, and experience greater psychological burden and impaired quality-of-life than whites.2-6 Since 2003, biologics have become increasingly popular for the treatment of moderate-to-severe psoriasis, and have resulted in higher patient satisfaction and compliance rates compared with oral, photo, or topical therapies.7,8 However, multiple studies have shown that African Americans have less access to biologics than whites.9,10 A 2015 study on the US Medicare population demonstrated that African American patients were 69% less likely to use biologics compared with white patients.11 However, the association between race and biologics has not been evaluated in a nationally representative psoriasis population. This population-based study aims to evaluate the impact of race on access to biologics among adult and pediatric psoriasis patients in the US. We hypothesized that our analysis would demonstrate racial differences in biologics access similar to previous studies.
We conducted a cross-sectional, population-based study using the Medical Expenditure Panel Survey (MEPS) national database from 2003-2018. We identified adults and children (mean age 49.36 years) with a reported diagnosis of psoriasis by the ICD-9 diagnosis code "696" or ICD-10 code "L40". Race was categorized based on the MEPS classification: white, Black, Asian or Pacific Islander, Alaska Native or American Indian, or multiple races; the latter two groups were later grouped together due to insufficient sample size. Access to an approved biologic medication for psoriasis was identified by the household-reported receipt of a prescription biologic. Multivariate logistic regression was used to investigate the association between race and access to biologics, adjusting for potential confounders including age, sex, ethnicity, insurance status, education level, poverty level, personal income, employment status, number of outpatient visits, region of care, and the Charlson Comorbidity Index.
A weighted total of 31,525,500 adult and child patients with psoriasis in the US were identified from 2003 to 2018. 87.1% self-identified as white, 6.5% self-identified as Black, 3.7% self-identified as Asian, and 2.7% self-identified as other races,
