title: Prevalence of nontuberculous mycobacteria in patients with bronchiectasis: a meta-analysis.
abstract: BACKGROUND
  Nontuberculous mycobacteria (NTM) have emerged as critical opportunistic pathogens of lung diseases recently. Patients with preexisting bronchiectasis are susceptible to NTM. Nevertheless, patients with preexisting bronchiectasis are susceptible to NTM but the prevalence of NTM pulmonary infection in different species and geographical areas is still not fully understood.
  
  
  METHODS
  The relevant data of the prevalence of NTM in patients with bronchiectasis were retrieved by searching the main databases such as PubMed, MEDLINE, Cochrane Library, and EMBASE. This meta-analysis was performed using Rev. Man 5.1 and Stata 11.0 software. The collected information of NTM prevalence was chosen as the effect size.
  
  
  RESULTS
  The results of the meta-analysis showed that the overall prevalence of NTM was 9.3% in patients with bronchiectasis. The further stratification of subgroup analysis indicated that the combined prevalence of NTM was higher in studies whose "sample size" was more than or equal to 100 (p = 0.002), in studies in which "time of study" was after or equal to 2002 (p < 0.001), in studies in which "participants' geographic location" was Asian (p < 0.001) and in studies whose "method of study" was retrospective (p = 0.002) as well, compared with corresponding groups.
  
  
  CONCLUSIONS
  Our findings suggested that the prevalence NTM infection is high in patients with bronchiectasis. A larger number of definitive randomized trials are still required to assess this research issue.
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Haiqing
authors.initials: H
authors.lastname: Chu
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Heping
authors.initials: H
authors.lastname: Xiao
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Zhemin
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Gui
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Sugang
authors.initials: S
authors.lastname: Gong
authors.affiliation: Department of Respiratory Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Liyun
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Radiology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China.
authors.forename: Xiwen
authors.initials: X
authors.lastname: Sun
keywords: bronchiectasis; meta-analysis; nontuberculous mycobacteria; prevalence