Tobacco smoking impact on tuberculosis treatment outcome: an observational study from West Africa

Both tuberculosis (TB) and tobacco smoking are preventable health hazards. Few studies have examined the relationship between TB and tobacco smoking in an African setting, where the two health burdens collide heavily. This study aimed to describe the severity of TB disease and treatment outcomes among smokers with TB compared with nonsmokers with TB in Guinea-Bissau.

We conducted a prospective follow-up study between 2003-2017 in Guinea-Bissau, enrolling adult patients with TB classified as nonsmokers or smokers. Disease severity was assessed using the Bandim TBscore. Multivariate logistic and Cox proportional hazard regressions were used to analyse treatment outcomes.

Of 1780 included patients, 385 were smokers who had smoked for a median 10 years (interquartile range [IQR] 5-20). No difference in disease severity at the time of diagnosis was observed. Smokers were not significantly more prone to a nonsuccessful treatment outcome, although a trend was seen (adjusted odds ratio [OR] 1.24, 95% confidence interval [CI] 0.91-1.70), and smokers tended to be more often lost to follow-up, but this also was not a significant finding (adjusted hazard ratio [HR] 2.09, 95% CI 0.89-4.94).

In a TB high-endemic setting with few tobacco smokers, smoking was not associated with disease severity or worse outcome, possibly because of socioeconomic confounders.