A randomized trial comparing standard outcomes in two treatment models for substance users with tuberculosis

Abstract

Setting: Chicago Department of Public Health (CDPH), TB Control Program.

Objectives: To compare anti-tuberculosis treatment outcomes using two different types of directly observed therapy (DOT) outreach workers.

Methods: Substance users diagnosed with TB from October 1996 to July 2000 were randomized to DOT administered by either 1) CDPH personnel (standard arm) or 2) previous substance-using human immunodeficiency virus/acquired immune-deficiency syndrome outreach workers (enhanced arm). Treatment completion was physician-determined, and adherence was estimated based on risk of missed DOT appointments.

Results: Of 94 patients, 46 were randomized to the standard and 48 to the enhanced arm. The standard arm had a significantly higher risk of non-completion of treatment (39% vs. 15%, RR 2.7, 95%CI 1.2-5.8), and a significantly higher risk of missing DOT appointments (RR 2.6, 95%CI 1.4-4.8). For both outcomes, housing instability was a significant predictor in multivariate analyses.

Conclusions: TB treatment completion and adherence among substance users was improved by the enhanced intervention; the familiarity of enhanced-arm DOT workers with the patients' social norms due to their own previous substance use may have made them more effective. Successful DOT in hard-to-reach populations may require strategies that directly address the population's circumstances and utilize DOT workers who are intimately familiar with patients' life situations.