Effect of quitting smoking on health outcomes during treatment for tuberculosis: secondary analysis of the TB & Tobacco Trial

Abstract

BackgroundDespite treatment, patients with tuberculosis (TB) who smoke have poorer outcomes compared with non-smokers. It is unknown, however, if quitting smoking during the 6 months of TB treatment improves TB outcomes.MethodsThe TB & Tobacco Trial was a double-blind, placebo-controlled randomised trial of cytisine for smoking cessation in 2472 patients with pulmonary TB in Bangladesh and Pakistan. In a secondary analysis, we investigated the hypothesis that smoking cessation improves health outcomes in patients during the TB treatment course. The outcomes included an eight-point TB clinical score, sputum conversion rates, chest X-ray grades, quality of life (EQ-5D-5L), TB cure plus treatment completion rates and relapse rates. These were compared between those who stopped smoking and those who did not, using regression analysis.ResultsWe analysed the data of 2273 (92%) trial participants. Overall, 25% (577/2273) of participants stopped smoking. Compared with non-quitters, those who quit had better TB cure plus treatment completion rates (91% vs 80%, p<0.001) and lower TB relapse rates (6% vs 14%, p<0.001). Among quitters, a higher sputum conversion rate at week 9 (91% vs 87%, p=0.036), lower mean TB clinical scores (−0.20 points, 95% CI −0.31 to −0.08, p=0.001) and slightly better quality of life (mean EQ-5D-5L 0.86 vs 0.85, p=0.015) at 6 months were also observed. These differences, except quality of life, remained statistically significant after adjusting for baseline values, trial arm and TB treatment adherence rates.ConclusionPatients with TB who stop smoking may have better outcomes than those who don’t. Health professionals should support patients in stopping smoking.

Effect of a brief motivational interview and text message intervention targeting tobacco smoking, alcohol use and medication adherence to improve tuberculosis treatment outcomes in adult patients with tuberculosis: a multicentre, randomised controlled trial of the ProLife programme in South Africa

“… 47 Smoking cessation also led to better TB treatment outcomes in a secondary analysis of a large tobacco cessation trial in patients with TB in Bangladesh and Pakistan. 48 Our non-significant result for smoking-related outcomes is not consistent with findings from our previous TB study, which used a single MI session and found that the chance of sustained smoking cessation was twice as high in the MI intervention group compared with the control group, 14 although with a less stringent exhaled CO cut-off point. Evidence on the effectiveness of MI for smoking abstinence in non-TB settings has been equivocal.…”

“…Conversely, in another study in India, intensive counselling for alcohol disorders led to significantly better TB treatment outcomes in the intervention group compared with the control group 47. Smoking cessation also led to better TB treatment outcomes in a secondary analysis of a large tobacco cessation trial in patients with TB in Bangladesh and Pakistan 48. Our non-significant result for smoking-related outcomes is not consistent with findings from our previous TB study, which used a single MI session and found that the chance of sustained smoking cessation was twice as high in the MI intervention group compared with the control group,14 although with a less stringent exhaled CO cut-off point.…”

Epidemiology: the current burden of tuberculosis and its determinants

“…Furthermore, smoking is associated with delayed smear and culture conversion, along with an increased probability of cavitary lesions [87,89,90]. Recent studies have shown elevated cure rates, reduced transmissibility, and reduced TB recurrence after smoking cessation compared with persistent smokers [91][92][93].…”

Common assumptions in tobacco control that may not hold true for South-East Asia

“… 31 In recent years, there has been an increasing awareness of the role of tobacco use in inducing TB, 32 the opportunities for TB health professionals to support tobacco cessation, 31 and the improvements observed in TB outcomes as a result of stopping smoking. 33 The emphasis and investment in TB control in SEAR can be further guided to address tobacco use as a key intervention to control TB.…”