Objectives: 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.
Methods: 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.
Results: 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.
Conclusions: 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.