Promoting adherence to treatment for tuberculosis: the importance of direct observation

Since 1993, WHO has recommended a strategy through which national govern- ments can meet their responsibility to treat patients and to prevent the spread of tuberculosis (TB). Four of the major elements of the strategy, which came to be known as DOTS, were political commitment by governments, improved laboratory services, a continuous supply of good-quality drugs, and a reporting system to document the progress (and failure) of treatment for individual pa- tients and of the programme. The fifth element, effective case management via direct observation of treatment by an independent and trained third party, was a response to decades of reports documenting the failure of patients to complete treatment. Put simply: direct observation of treatment is an integral and essential component of DOTS. WHO has reported that more than 30 million patients with TB have been treated with its five-element DOTS strategy, resulting in cure rates of > 80% and default rates of < 10%.1 WHO's re- cently announced Global Plan to Stop TB highlights the need to expand DOTS through "standardized treatment, under proper case management conditions, including directly observed treatment to reduce the risk of acquiring drug resis- tance, and support of patients to increase adherence to treatment and chance of cure".2 However, the value of the direct observation component of DOTS has been questioned in a recent systematic review, in which it was suggested that direct observation of treatment is un- necessary and disrespectful of patients.3 Both self-administered treatment and treatment observation by a family mem- ber have been proposed as acceptable alternatives. We challenge the validity of these assertions. What is the validity of trials reported to support self-administration of treatment? The random controlled trial is the gold standard to identify the effect of a single variable on patient treatment. To our knowledge, only three such trials have compared self-administered (i.e. unobserved) dosing with direct observa- tion provided by someone outside the family.4-6 All three trials reported low rates of treatment success in both arms of the study, suggesting that direct obser- vation was not implemented effectively. The reported cure rates of only 38%, 41% and 64% in the patients receiving directly-observed therapy 4-6 are far be-