ESTIMATION OF CURE, RELAPSE AND SUCCESS RATES OF SHORT-COURSE CHEMOTHERAPY IN THE TREATMENT OF PULMONARY TUBERCULOSIS : A META-ANALYSIS

摘要

The success of tuberculosis control programmes depends on many factors, especially on cure and relapse rates following anti- tuberculosis treatment. Studies of success rate of Short Course Chemotherapy (SCC) in the treatment of pulmonary tuberculosis are many; as operational research studies or Randomised Controlled Trials (RCTs). Here, we have considered RCTs because of their; robustness. However, there are only 29 RCTs in the world wherefrom the success of SCC of 6-9 months' duration in the treatment of pulmonary tuberculosis can be judged. Among these RCTs, a considerable variation in the sample sizes, ranging from 159 to 1040 was observed. The cure rates obtained varied from 84% to 95%'across the studies, while 95% confidence intervals gave the lower bound as 79%. Similarly, relapse rates varied from 1% to 16%. In our study, an attempt has been made to make a global estimate of cure, relapse and success rates of SCC , through meta-analysis of the eligible RCTs. There was heterogeneity among the RCTs on each of these rates (p<0.001). After correction for heterogeneity, the estimated cure rate was 97.7% (95% confidence interval(CI), 96.5% to 98.8%), the relapse rate was estimated to be 6.1% (95% CI, 4.0% to 8.2%), and the success rate was estimated as 91.5% (95% CI, 88.7% to 94.4%). Resistance to one or more drugs contributed 24% of the estimated relapse rate which suggests that surveillance activity on drug resistant tuberculosis should be undertaken.