Tuberculosis

Directly Observed Therapy for Tuberculosis No Better than Self-Administration

People who self-administered drugs to treat tuberculosis (TB) and those receiving directly observed therapy (DOT) had similar outcomes, according to a meta-analysis of 10 studies described in the July 2013 issue of Clinical Infectious Diseases. 

Tuberculosis treatment can last for several months, and people who fail to complete a course of therapy can develop drug resistance and infection others. Many public health programs around the world have adopted directly observed therapy, in which healthcare provider, social workers, or others watch to see that patients take their drugs as directed. While this is resource-intensive and inconvenient for patients, DOT is widely thought to improve adherence and lead to better outcomes.

Jotam Pasipanodya and Tawanda Gumbo from the University of Texas Southwestern Medical Center performed a meta-analysis of prospective studies conducted between 1965 and 2012, looking at microbiological treatment failure, relapse, and acquired drug resistance among adults with pulmonary TB using directly observed versus self-administered short-course therapy.

Results 

• The researchers identified 10 studies -- 5 randomized and 5 observational -- that met selection criteria.
• Altogether, these studies included 8774 patients allocated to DOT and 3708 allocated to self-administered therapy.
• 1.5% of patients using DOT experienced microbiological treatment failure, compared with 1.7% of those using self-administration, not a significant difference.
• Relapse rates were 3.7% vs 2.3%, respectively, also not significant.
• Rates of acquired drug resistance were 1.5% vs 0.9%, respectively, again not significant.
• The pooled risk differences for treatment failure, relapse, and drug resistance between DOT and self-administration were 0.0, 0.01, and 0.0, respectively, indicating essentially no difference.

Based on these findings, the study authors concluded, "DOT was not significantly better than [self-administered therapy] in preventing microbiologic failure, relapse, or [acquired drug resistance] in evidence-based medicine. Resources should be shifted to identify other causes of poor microbiologic outcomes."

"We found that defaulting [treatment interruption or discontinuation] rates were indeed reduced by DOT," they elaborated in their discussion. "However, despite the poorer defaulting rates on [self-administered therapy], we found no difference in microbial failure, [acquired drug resistance], or relapse, between DOT and [self-administered therapy]."

"We speculate that the DOTS program is associated with a large infusion of resources such as upgrade in expertise and a reliable supply of drugs, and that the regular contact with a patient further provides a higher level of support apart from direct supervision of therapy, which would lead to apparent improvement in outcomes in retrospective studies, independent of DOT," they continued.

"Our findings should not be read as questioning the entire DOTS program, but are limited to supervision of patients swallowing pills," they added. "It may be that requiring patients to frequently come and pick up their medicines or to be observed swallowing their pills could actually impose economic hardships in some parts of the world, leading to microbiologic failure."

6/13/13

Reference

JG Pasipanodya and T Gumbo. A Meta-Analysis of Self-Administered vs Directly Observed Therapy Effect on Microbiologic Failure, Relapse, and Acquired Drug Resistance in Tuberculosis Patients. Clinical Infectious Diseases 57(1):21-31. July 2013.