BACKGROUND: Several systematic reviews suggest that intermittent pulmonary tuberculosis (TB) chemotherapy is effective, but intensity (daily versus intermittent) and duration of rifampicin use (intensive phase only versus both phases) have not been distinguished. In addition, the various outcomes (success, failure, relapse, and default) have only selectively been evaluated.
METHODS: We conducted a meta-analysis of proportions using all four outcomes as multi-category proportions to examine the effectiveness of WHO category 1 TB treatment regimens. Database searches of studies reporting treatment outcomes of HIV negative subjects were included and stratified by intensity of therapy and duration of rifampicin therapy. Using a bias-adjusted statistical model, we pooled proportions of the four treatment outcome categories using a method that handles multi-category proportions.
RESULTS: A total of 27 studies comprising of 48 data sets with 10,624 participants were studied. Overall, treatment success was similar among patients treated with intermittent (I/I) (88%) (95% CI, 81-92) and daily (D/D) (90%) (95% CI, 84-95) regimens. Default was significantly less with I/I (0%) (95% CI, 0-2) compared to D/D regimens (5%) (95% CI, 1-9). Nevertheless, I/I relapse rates (7%) (95% CI, 3-11) were higher than D/D relapse rates (1%) (95% CI, 0-3).
CONCLUSION: Treatment regimens that are offered completely intermittently versus completely daily are associated with a trade-off between treatment relapse and treatment default. There is a possibility that I/I regimens can be improved by increasing treatment duration, and this needs to be urgently addressed by future studies.