Timing of default from tuberculosis treatment: a systematic review

To provide a systematic assessment of the timing of default from tuberculosis (TB) treatment which could help to quantify the potential contribution of new shorter duration TB drugs to global TB control.

We performed a systematic review following QUOROM guidelines. MEDLINE was searched from 1998 to the present using the terms TB and default or drop-out or compliance or adherence and therapy. A total of 840 articles were returned. A further detailed manual review selected 15 randomized trials and observational studies that reported timing of drop-out and focused on developing countries.

The selected studies comprised randomized controlled trials, retrospective record reviews, and qualitative assessments and spanned 10 countries. Both directly observed treatment (DOT) and non-DOT programs were represented. Thus results were highly heterogeneous and not statistically aggregated. Data suggest, but do not conclude, that the majority of defaulters across the studies completed the 2-month intensive phase of treatment.

There is insufficient high-quality comparable information on the timing of default from TB treatment to permit any firm conclusions on trends in default. However, a substantial proportion of defaulters appear to leave treatment in the later stages of the current 6-month regimen, suggesting that new TB chemotherapeutic agents which can reduce the length of treatment have the potential to improve global TB treatment success rates.