title: Baseline pulmonary function and quality of life 9 years later in a middle-aged Chinese population.
abstract: OBJECTIVE
  This research examined the association of baseline pulmonary function with future quality of life (QOL).
  
  
  METHODS
  We collected baseline pulmonary function data in 1993 and 1994, and assessed QOL using the Chinese 35-Item Quality of Life Instrument in 2002 in a cohort of 1,356 participants. We used Pearson correlation analysis, multivariate analysis of variance, and multivariate linear regression analysis to assess the relationship between pulmonary function and QOL.
  
  
  RESULTS
  The baseline percentage of age- and height-predicted FEV1 (FEV1%) was significantly correlated with the resurvey total QOL score (r = 0.126, p < 0.001) and with QOL scores for the general (r = 0.074, p = 0.006), physical (r = 0.085, p = 0.002), independence (r = 0.178, p < 0.001), and psychological (r = 0.064, p = 0.018) domains but not with the social and environmental domains after adjusting for age and sex. These associations were weaker for the percentage of age- and height-predicted FVC. Multiple linear regression showed that the above associations were independent of baseline and resurvey smoking status. Inclusion of respiratory symptoms in the model reduced the regression coefficients from 0.82 to 0.41 for the total QOL score and from 1.43 to 0.94 for the independence domain score, for a 10% change in FEV1%. The age- and sex-adjusted mean total QOL scores were 78, 76, 76, and 69, respectively (p < 0.001), for the groups of normal, symptomatic only, impaired pulmonary function only, and both symptomatic and impaired pulmonary function. This trend was also significant for the general, physical, independence, and psychological domain scores.
  
  
  CONCLUSIONS
  Impaired baseline pulmonary function has a significant negative impact on QOL in later life that is independent of age, sex, height, and smoking status and is largely mediated through the development of chronic respiratory symptoms.
authors.affiliation: Department of Epidemiology, Cardiovascular Institute and Fu Wai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, #167, Beilishi Rd, Xicheng, Beijing, 100037, People's Republic of China.
authors.forename: Gaoqiang
authors.initials: G
authors.lastname: Xie
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Shi
authors.forename: Beifan
authors.initials: B
authors.lastname: Zhou
authors.forename: Puhong
authors.initials: P
authors.lastname: Zhang
authors.forename: Yangfeng
authors.initials: Y
authors.lastname: Wu
mesh_terms: D002681:China; D005260:Female; D005541:Forced Expiratory Volume; D006306:Health Surveys; D006801:Humans; D008171:Lung Diseases / Q000503:physiopathology / Q000523:psychology; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012129:Respiratory Function Tests; D013147:Spirometry / Q000379:methods; D014797:Vital Capacity