# Quantifying the evidence and burden of smoking behaviour on tuberculosis incidence among adult population: a systematic review and meta-analysis

## TL;DR

This study finds that smoking significantly increases the risk of tuberculosis in China, suggesting that smoking cessation could help reduce TB incidence.

## Contribution

A meta-analysis showing a strong link between smoking and tuberculosis incidence, with implications for public health strategies in China.

## Key findings

- Smokers have a 1.77 times higher odds of TB incidence compared to non-smokers.
- Hazard ratios show smokers have a 2.39 times higher risk of TB.
- The study links smoking to worsened TB outcomes and suggests pandemic-related factors may have increased smoking-related TB risks.

## Abstract

Tuberculosis (TB) remains a major public health challenge in China and worldwide, with smoking being a key modifiable risk factor. Given China’s large population and rising smoking rates, this paper aims to examine the link between smoking and TB incidence.

We systematically searched six databases from inception for studies reporting smoking exposure, TB outcomes, and smoker-non-smoker comparisons. Two reviewers independently screened records, extracted data, and assessed bias. We analysed smoking-TB associations using random-effects meta-analysis of odds ratios (ORs) and hazard ratios (HRs).

We included 17 studies reporting ORs and 7 studies reporting HRs in the quantitative synthesis. The pooled OR for TB incidence among smokers compared with non-smokers was 1.77 (95% confidence interval (CI) = 1.29–2.43), indicating a statistically significant increase in risk of TB. For studies reporting hazard ratios, the pooled estimate was 2.39 (95% CI = 1.28–4.45), showing a significant association between smoking and increased TB incidence.

Both active and passive smoking significantly elevate the risk of TB and worsen its outcomes in China. Our result indicate that COVID-19 pandemic may have indirectly exacerbated smoking-related risks through disruptions to TB services, heightened psychosocial stress, and shifts in smoking behaviours, with potential implications for TB risk and outcomes. Thus, integrating smoking cessation strategies into TB programmes, focusing on heavy smokers in especially high-prevalence areas, and raising public awareness could enhance efforts to prevent and control TB worldwide.

PROSPERO: CRD420251070123.