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

TY - JOUR

T1 - Effect of quitting smoking on health outcomes during treatment for tuberculosis

T2 - Secondary analysis of the TB & Tobacco Trial

AU - Siddiqi, Kamran

AU - Keding, Ada

AU - Marshall, Anna Marie

AU - Dogar, Omara

AU - Li, Jinshuo

AU - Huque, Rumana

AU - Fatima, Razia

AU - Khan, Amina

AU - Elsey, Helen

AU - Gabe, Rhian

AU - Kotz, Daniel

AU - Sheikh, Aziz

N1 - Funding Information: Funding The study was funded by the European Union Horizon 2020 research and innovation programme (680995).

PY - 2021/7/16

Y1 - 2021/7/16

N2 - Background Despite 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. Methods The 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. Results We 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. Conclusion Patients with TB who stop smoking may have better outcomes than those who don't. Health professionals should support patients in stopping smoking.

AB - Background Despite 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. Methods The 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. Results We 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. Conclusion Patients with TB who stop smoking may have better outcomes than those who don't. Health professionals should support patients in stopping smoking.

KW - smoking cessation

KW - tobacco and the lung

KW - tobacco control

KW - tuberculosis

UR - http://www.scopus.com/inward/record.url?scp=85110557785&partnerID=8YFLogxK

U2 - 10.1136/thoraxjnl-2020-215926

DO - 10.1136/thoraxjnl-2020-215926

M3 - Article

C2 - 34272336

AN - SCOPUS:85110557785

SN - 0040-6376

VL - 77

SP - 74

EP - 78

JO - Thorax

JF - Thorax

IS - 1

ER -