Drug Utilization Patterns and Adherence in Patients on Systemic Medications for the Treatment of Psoriasis: A Retrospective Comparative Cohort Study

Publication date: Available online 5 July 2018

Source: Journal of the American Academy of Dermatology

Author(s): Erica D. Dommasch, Moa P. Lee, Cara J. Joyce, Elizabeth M. Garry, Joshua J. Gagne

Abstract

Background

Non-adherence to systemic treatments for psoriasis leads to treatment failure and increased healthcare utilization.

Objective

Examine drug utilization patterns and adherence for new users of systemic medications for psoriasis.

Methods

We conducted a retrospective comparative cohort study using a large US health insurance claims database including psoriasis patients who were new users of acitretin, adalimumab, etanercept, methotrexate, and ustekinumab. Adherence was measured using proportion of days covered (PDC) dichotomized as adherent (≥0.80) or non-adherent (<0.80). Odds ratios (ORs) and 95% confidence intervals (CIs) comparing adherence to each exposure (acitretin, adalimumab, etanercept, and ustekinumab) to the referent (methotrexate) were estimated via logistic regression, with pairwise 1:1 propensity score (PS) matching to adjust for potential confounders.

Results

22,742 patients were new users of systemic medications. Compared to methotrexate, we report greater adherence among users of adalimumab, etanercept, and ustekinumab [PS-matched OR (95% CI) = 2.24 (2.05, 2.45), 1.77 (1.63, 1.92), and 2.54 (2.24, 2.87), respectively], and lower adherence among new users of acitretin [0.57 (0.50, 0.63)].

Limitations

Unable to evaluate reasons for discontinuation.

Conclusions

We report greater adherence in new users of biologics when compared to methotrexate. Further research is needed to understand overall low adherence to systemic medications for psoriasis.