Smoking and risk of death due to pulmonary tuberculosis: a case-control comparison in 103 population centers in China

OBJECTIVE: To examine the relationship between smoking and the risk of tuberculosis (TB) mortality in a large population-based case-control study in China using an alternative control group selection design. METHODS: During 1989-1991, a nationwide mortality survey was conducted of deaths among adults from 1986 to 1988. Surviving spouses or other informants provided detailed information about their own as well as the deceased person's smoking history. For the present study, all persons who died of TB at age >= 40 were used as cases, whereas all surviving spouses of deceased persons who died from causes other than those attributed to smoking were used as controls. RESULTS: It was estimated that for 22.5% of men and 6.6% of women, smoking was a contributing factor for TB deaths. Although variations in TB death rates by smoking status were not obvious before the age of 60, these differences increased substantially with age thereafter. This trend occurred in both urban and rural areas, although rural TB death rates were double those observed in urban areas. CONCLUSIONS: Tobacco smoking was associated with a large number of deaths from TB in China. The current study confirms results from previous studies about the relationship between smoking and TB mortality.