title: A systematic review and meta-analysis-does chronic obstructive pulmonary disease predispose to bronchopleural fistula formation in patients undergoing lung cancer surgery?
abstract: BACKGROUND
  we conducted this systematic meta-analysis to determine the association between chronic obstructive pulmonary disease (COPD) and risk of bronchopleural fistula (BPF) in patients undergoing lung cancer surgery.
  
  
  METHODS
  Literature retrieval was performed in PubMed, Embase and the Web of Science to identify the full-text articles that met our eligibility criteria. Odds ratio (OR) with 95% confidence interval (CI) served as the summarized statistics. Q-test and I(2)-statistic were used to evaluate the level of heterogeneity. Sensitivity analysis was performed to further examine the stability of pooled OR. Publication bias was detected by both Begg's test and Egger's test.
  
  
  RESULTS
  Eight retrospective observational studies were included into this meta-analysis. The overall summarized OR was 2.03 (95% CI: 1.44-2.86; P<0.001), revealing that COPD was significantly associated with the risk of BPF after lung cancer surgery. In subgroup analysis, the relationship between COPD and BPF occurrence remained statistically prominent in the subgroups stratified by statistical analysis (univariate analysis, OR: 1.91; 95% CI: 1.35-2.69; P<0.001; multivariate analysis, OR: 3.18; 95% CI: 1.95-5.19; P<0.001), operative modes (pneumonectomy, OR: 2.11; 95% CI: 1.15-3.87; P=0.016) and in non-Asian populations (OR: 2.36; 95% CI: 1.18-4.73; P=0.016). No significant impact of COPD on BPF risk was observed in Asian patients (OR: 1.48; 95% CI: 0.85-2.57; P=0.16). No significant heterogeneity or publication bias was discovered across the included studies.
  
  
  CONCLUSIONS
  Our meta-analysis indicates that COPD can significantly predispose to BPF formation in patients undergoing lung cancer surgery. Because some limitations still exist in this meta-analysis, our findings should be further verified and modified in the future.
authors: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610065, China ;
authors: Shuang-Jiang
authors: SJ
authors: Li
authors: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610065, China ;
authors: Xu-Dong
authors: XD
authors: Zhou
authors: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610065, China ;
authors: Jian
authors: J
authors: Huang
authors: Institution of Medical Statistics, West China School of Public Health, Sichuan University, Chengdu 610065, China.
authors: Jing
authors: J
authors: Liu
authors: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610065, China ;
authors: Long
authors: L
authors: Tian
authors: Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu 610065, China ;
authors: Guo-Wei
authors: GW
authors: Che
keywords: Bronchopleural fistula (BPF); chronic obstructive pulmonary disease (COPD); lung cancer surgery; meta-analysis