Directly observed therapy for treating tuberculosis

Directly observed therapy (DOT) has no quantitatively important effect on cure rates or treatment completion in people receiving treatment for tuberculosis (TB).

So concludes a systematic review of randomized controlled trials conducted in low-, middle, and high-income countries. The review is to be published in Issue 2, 2006 of The Cochrane Library.

To fight TB people need to take medication regularly for at least six months, but many people fail to complete the regimen. One approach to improving compliance has been to directly observe people as they swallow the tablets. The hope is that this would ensure that the tablets are taken regularly.

One of the problems evaluating these approaches to treating TB has been that various other forms of support are often added at the same time. Some programmes include social support, others include housing, and still others give out food tokens. In this review the Cochrane Review Authors teased out the benefit that came just from the direct observation element of the programme.

Their conclusion was stark. "Randomised controlled trials provide no assurance that the routine use of direct observation in low-income, and middle income countries improves cure or treatment completion in people with TB. Furthermore there is no rigorous evidence to support the use of direct observation for prophylaxis in people with latent TB," say the Authors.

"DOT is a controversial and expensive intervention, and there appears to be no sound reason to advocate its routine use until we understand the situation in which it may be beneficial," says lead Author Professor Jimmy Volmink, Deputy Dean of Research, Faculty of Health Sciences, Stellenbosch University, South Africa

Until that evidence is available, the authors recommend that attention is focussed on interventions that boosts patient motivation and provide incentives or support.