Smoking cessation to prevent death and tuberculosis recurrence after treatment: A prospective cohort study with a seven-year follow-up in China

Although there is consistent evidence that smoking is a risk factor associated with tuberculosis (TB), whether smoking cessation improves treatment outcomes and reduces the risk of TB recurrence remains understudied. We conducted a prospective cohort study with a seven-year follow-up in China. We recruited newly-diagnosed TB patients and classified them as non-smokers, ex-smokers, and current smokers. Current smokers were invited to participate in a smoking cessation intervention programme. We used a Cox proportional hazards model to assess the risk of death among TB patients and the risk of recurrence among successfully treated patients. In total, 634 (79.2%) patients completed anti-TB treatments and 115 (14.4%) patients died. We confirmed the existence of a dose-response relationship between smoking frequency and the risk of TB recurrence (the slope of the fitted line >0; P