Directly observed therapy for treating tuberculosis

Abstract

Background: Up to half the people with tuberculosis do not complete their treatment. Thus strategies that improve adherence to treatment regimens are important.

Objectives: To compare policies of directly observed therapy with self treatment at home in people requiring treatment for clinically active tuberculosis, or requiring medication for prevention of active disease, on cure and/or treatment completion.

Search strategy: We searched The Cochrane Controlled Trials Register (Issue 3, 2002), the Cochrane Infectious Diseases Group trials register (August 2002), MEDLINE (1966 to August 2002), EMBASE (1980 to August 2002), LILACS (accessed August 2002), and reference lists of articles. We also contacted experts in the field.

Selection criteria: Randomized and quasi-randomized trials of appointed agents (health worker, community volunteer, or family member) directly observing people swallowing their antituberculous drugs compared with self treatment for tuberculosis.

Data collection and analysis: Two reviewers independently assessed the methodological quality of the trials and extracted data.

Main results: Six studies included (n=1910). Patients allocated to directly observed therapy (DOT) compared had similar outcomes in relation to cure (Relative Risk (RR) 1.06; 95% confidence interval (CI) 0.98 to 1.14); and cure plus treatment completion (RR 1.06; 95% CI 1.00 to 1.13). A stratified analysis by the appointed agent (health professional, lay health worker, or family/community member) did not detect any important differences. One study conducted in an optimal setting in which participants were given a choice of supervisor did show modest benefit (cure RR 1.13; 95% CI 1.04 to 1.24; cure plus treatment completion RR 1.11; 95% CI 1.03 to 1.18). Two trials assessed the effects of direct observation on completion of antituberculous preventive therapy in intravenous drug users in the USA. One study found no difference between DOT by an outreach nurse and routine self treatment (RR 1.02; 95% CI 0.89 to 1.18). The other study compared completion rates between participants who chose their DOT location and those receiving DOT at a community clinic and failed to demonstrate a significant difference (RR 0.88; 95% CI 0.63 to 1.23).

Reviewer's conclusions: Well conducted trials comparing a policy of directly observed therapy with self treatment at home have been carried out in low, middle, and high income countries. Studies include people on treatment or people at high risk of developing tuberculosis. The effects of direct observation on cure or treatment completion were similar to those of self-administered treatment.