Biologic Treatment of Psoriasis and Tuberculosis Testing: A Retrospective Analysis

Background: Current recommendations for biologic use in psoriasis recommend baseline TB screening with IGRA. Studies have found in low TB prevalence countries that TB conversion occurs at low rates in those utilizing biologic therapies. Objectives: To evaluate utilization and cost effectiveness of TB testing in patients with psoriasis being treated with biologics. Methods: We retrospectively queried a national commercial claims database (Truven Health MarketScan) from 1/1/2014 to 12/31/2018 to investigate the use of TB screening and disease prevalence among patients with psoriasis being treated with a biologic agent. Inclusion criteria consisted of psoriasis disease status, continuous utilization of a biologic for one year prior and three years after the first biologic claim; and no claims for TB within the year prior to starting the biologic. Results: 3,421 patients with psoriasis and concurrent biologic treatment use were included in the study. 84.7% (2,897) had a baseline TB test within 15 months prior to first claim of biologic use. Baseline tests were primarily IGRA (75.8%, n=2,195) with PPD tests only being used in 24.2% (n = 702) of patients. Total cost for baseline TB test in the cohort amounts to $738,117. TB was diagnosed in 4.1% (n = 147) patients and TNF-α inhibitors was the most frequently prescribed biologic. Conclusions: The majority of patients diagnosed with psoriasis had a claim for baseline TB testing. Current recommendations surrounding biologics and TB screening should take into account the high cost of baseline TB testing and the low rate of TB prevalence among patients on biologics.