Tuberculosis remains the leading cause of death attributed to smoking in South Africa: results from the South African death certificate study

Background The question 'Was the deceased a smoker five years ago?' was introduced in mid-1997 on a revised South African death notification form to provide a direct estimate of tobacco attributed mortality, using a case-control method for ongoing monitoring of the tobacco epidemic. This paper updates previous reports (1999 to 2007). Methods This analysis included 772,975 deaths from 2000 to 2013, for persons 35 to 74 years with information about age, year of death, sex, province of death, educational grade, marital status, population group and smoking status (current smoker vs. not). Cases comprised deaths due to diseases expected to be associated with smoking; controls comprised deaths from selected conditions expected to be unrelated to smoking. Deaths due to HIV without TB, external causes, cirrhosis, mental disorders, maternal and perinatal conditions and diabetes were excluded. Smoking-associated relative risks were assumed to be the case/control versus smoker/ex & non-smoker odds ratios, adjusted for 5-year age group, education, province, year of death, marital status. Deaths were extrapolated to the NBD national annual estimates for 2012. Results Smoking-associated relative risks were highest for lung and upper aero-digestive cancers and COPD amongst the white and coloured (mixed race) populations reflecting their relatively higher smoking prevalence. When extrapolated to NBD estimates for 2012, smoking-attributable deaths accounted for approximately 14 329 out of 284 949 total deaths in persons aged 35 - 74 years (5%). Tuberculosis remains the leading cause of smoking-attributable deaths (approx 24%) followed by COPD (approx 19%) and lung cancer (approx 17%). Conclusions Different population groups in South Africa are at different stages of the tobacco epidemic and ongoing monitoring by population group is required. The cause profile of smoking-attributable mortality in South Africa differs from that in developed countries and suggests that tobacco cessation should be incorporated into the South African TB programme.