Lower Socioeconomic Status is Associated With Decreased Therapeutic Response to the Biologic Agents in Psoriasis Patients

February 2016 | Volume 15 | Issue 2 | Original Article | 147 | Copyright © February 2016

Eric P. Sorensen BS,ab Haitham Algzlan MD,a Shiu-chung Au MD,a Caren Garber BA,ac Kristina Fanucci BS,ac Michelle Bichchau Nguyen MD MPH,ac and Alice B. Gottlieb MD PhDac

aDepartment of Dermatology, Tufts Medical Center, Boston, MA
bUniversity of California, San Diego, School of Medicine, San Diego, CA
cTufts University School of Medicine, Boston, MA

BACKGROUND: Lower socioeconomic status is associated with poorer overall health outcomes. However, few studies have examined the impact of socioeconomic status on psoriasis.
OBJECTIVE: To examine the impact of individual socioeconomic status on systemic therapeutic outcomes amongst psoriasis patients.
METHODS: The study analyzed 156 psoriasis patients treated at the Tufts Medical Center Department of Dermatology from 2008-2014. Individual socioeconomic status was inferred from neighborhood income, defined as the percentage of households with income below the federal poverty line (% below FPL) in the patient’s census tract. The following outcomes were compared between socioeconomic groups: improvement in simple measure for assessing psoriasis activity (S-MAPA) score at 12 weeks, primary and secondary drug failure rates, and incidence of documented medication non-adherence.
RESULTS: Those patients living in relatively poorer neighborhoods (% below FPL ≤10%) experienced a significantly decreased improvement in S-MAPA score at 12 weeks of biologic treatment when compared to those in relatively richer neighborhoods (% below FPL >10%), 23.2% vs. 45.5%, P=0.021. Patients living in poorer neighborhoods also had a significantly higher rate of primary drug failure when treated with biologics (34.7% vs. 18.4%, P=0.039) and were significantly more likely to have ≥1 documented instance of medication non-adherence when treated with biologics (45.5% vs. 8.8%, P<0.001).
LIMITATIONS: Retrospective design, small sample size
CONCLUSIONS: Our study offers preliminary data that suggests lower socioeconomic status may be associated with decreased clinical response to the biologic agents, presumably through decreased medication adherence.

J Drugs Dermatol. 2016;15(2):147-153.


Psoriasis is a chronic systemic inflammatory disorder characterized by scaly, erythematous plaques with a worldwide prevalence ranging from 1-6%.1 Psoriasis has a significant negative impact on quality of life.2 For example, it may limit physical functioning due to pain related to plaques or the presence of psoriatic arthritis.3 It also substantially impacts workplace productivity due to occupational discrimination and an increased number of missed workdays.4
Psoriasis patients also suffer significant financial burden due to the chronic nature of the disease and the expensive medications often required for treatment. In particular, with the introduction of the biologic medications, patients have faced a significant increase in the costs of psoriasis treatment.5 In 2008, it was estimated that monthly direct costs, such as medical bills and prescriptions, were $614 per patient and indirect costs, such as loss of work productivity, were $229 per patient.6 Further, it has been demonstrated that these costs increase incrementally with psoriasis severity.7
In general, individuals of lower socioeconomic status demonstrate poorer health outcomes due to fewer available resources and reduced access to care.8 More specifically, in other rheumatologic disorders, low socioeconomic status has been shown to negatively impact the disease state. For example, in rheumatoid arthritis, lower socioeconomic status (SES) is associated with increased disease severity and decreased health care utilization9 and in systemic lupus erythematosus, low SES is associated with more end organ damage10 and poorer long-term survival.11 In psoriasis, while several large cross-sectional studies have found no significant difference in disease prevalence among different socioeconomic groups,12,13 there is little published research on the impact of socioeconomic status on psoriasis outcomes. The purpose of this study is to analyze the impact of individual socioeconomic status on systemic therapeutic outcomes, medication failure rates, and medication adherence amongst psoriasis patients at a major tertiary academic center.