title: Long-acting beta-agonists reduce mortality of patients with severe and very severe chronic obstructive pulmonary disease: a propensity score matching study.
abstract: BACKGROUND
  Long-acting beta-agonists were one of the first-choice bronchodilator agents for stable chronic obstructive pulmonary disease. But the impact of long-acting beta-agonists on mortality was not well investigated.
  
  
  METHODS
  National Emphysema Treatment Trial provided the data. Severe and very severe stable chronic obstructive pulmonary disease patients who were eligible for volume reduction surgery were recruited at 17 clinical centers in United States during 1988-2002. We used the 6-10 year follow-up data of patients randomized to non-surgery treatment. Hazard ratios for death by long-acting beta-agonists were estimated by three models using Cox proportional hazard analysis and propensity score matching were measured.
  
  
  RESULTS
  The pre-matching cohort was comprised of 591 patients (50.6% were administered long-acting beta-agonists. Age: 66.6 ± 5.3 year old. Female: 35.4%. Forced expiratory volume in one second (%predicted): 26.7 ± 7.1%. Mortality during follow-up: 70.2%). Hazard ratio using a multivariate Cox model in the pre-matching cohort was 0.77 (P = 0.010). Propensity score matching was conducted (C-statics: 0.62. No parameter differed between cohorts). The propensity-matched cohort was comprised of 492 patients (50.0% were administered long-acting beta-agonists. Age: 66.8 ± 5.1 year old. Female: 34.8%. Forced expiratory volume in one second (%predicted) 26.5 ± 6.8%. Mortality during follow-up: 69.1%). Hazard ratio using a univariate Cox model in the propensity-matched cohort was 0.77 (P = 0.017). Hazard ratio using a multivariate Cox model in the propensity-matched cohort was 0.76 (P = 0.011).
  
  
  CONCLUSIONS
  Long-acting beta-agonists reduce mortality of severe and very severe chronic obstructive pulmonary disease patients.
authors.affiliation: Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Japan. nobuyuki_horita@yahoo.co.jp
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Horita
authors.forename: Naoki
authors.initials: N
authors.lastname: Miyazawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Ryota
authors.initials: R
authors.lastname: Kojima
authors.forename: Naoko
authors.initials: N
authors.lastname: Kimura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kaneko
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
mesh_terms: D000318:Adrenergic beta-Agonists / Q000627:therapeutic use*; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D057216:Propensity Score; D016016:Proportional Hazards Models; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy* / Q000401:mortality*; D012307:Risk Factors; D012720:Severity of Illness Index; D016019:Survival Analysis; D015996:Survival Rate
chemical_list: D000318:Adrenergic beta-Agonists