Evaluating the impact of tuberculosis control: number of deaths prevented by short-course chemotherapy in China

Background Tuberculosis (TB) is still amongst the most important causes of human morbidity and mortality killing approximately two million people each year. Standard short-course chemotherapy (SSCC) can rapidly control illnes s and dramatically reduce the chance of death, but the impact of treatment has rarely been evaluated in these terms. Method We developed a mathematical model that makes use of routinely-collec ted data to calculate the number of deaths directly prevented by TB treatme nt (i.e. excluding those due to reduced transmission). The method was appli ed to the world's largest TB control programme covering over 500 million pe ople in 12 provinces of China. Results Counties which had been enrolled in the programme since 1991 were, by 1997, preventing at least 46% (37-56%) of the TB deaths that would other wise have occurred. If replicated across the entire TB control programme ar ea, this would amount to 30 000 (range 26 000-59 000) deaths directly preve nted each year. Conclusions Short-course chemotherapy has substantially reduced TB mortalit y in half of China. The analytical method described here could be applied t o TB control operations in many other countries, and should help to quantif y the true burden of tuberculosis alleviated by SSCC.