Excess Mortality and Risk Factors for Mortality Among a Cohort of TB Patients from Rural South India

Objectives: To estimate the excess general mortality among tuberculosis (TB) patients in a rural area (Tiruvallur) and identify risk factors for TB-related mortality.

Setting: The study population consisted of all TB patients aged >or=15 years who were registered under the Revised National Tuberculosis Control Programme (RNTCP) during the years 2000 to 2003 at Velliyur TB unit (TU) in south India.

Design: This is a retrospective cohort study of 3405 patients treated under the DOTS strategy, followed up from the date of start of treatment till the date of interview (for the survivors) or the date of death (for those who died).

Results: There were 2710 (79.6%) survivors and 695 (20.4%) deaths. The excess general mortalities for the cohort, expressed as standardised mortality ratio (SMR), was 4.2 (95%CI 3.9-4.5). High SMR values were obtained for patients belonging to the 15-44 years age group (12.1), patients on Category II regimen (9.3), treatment failures (9.1) and defaulters (7.8). The adjusted hazards ratios (aHR) were high for patients aged 45-59 years (1.9), >or=60 years (3.1) and with incomplete treatment due to default or failure (6.4).

Conclusion: TB is one of the main causes of mortality in the younger age group. Among TB patients, the major risk factors for mortality are old age (>or=45 years) and incomplete treatment.