title: [Quality of life as a time-dependent covariable in cox regression analysis and its application].
abstract: OBJECTIVE
  To present a statistical method for combined evaluation of the quality of life and survival time and to study some issues in its application.
  
  
  METHODS
  Based on Cox regression model, quality of life was used as a time-dependent covariable in analysis of the influence factors for the effectiveness of detoxification in 212 drug addicts.
  
  
  RESULTS
  The influence factors entered the regression equation were ways of detoxification for drug abusers, marital status, mode of drug abuse, frequency of detoxification, maternal educational level, maternal occupation, family atmosphere and help and encourage from their relatives and friends, with their hazard ratios of 0.673, 1.315, 1.319, 0.867, 1.120, 1.318, 0.724 and 1.150, respectively.
  
  
  CONCLUSIONS
  Combined statistical analysis of quality of life and survival time was a better method for the evaluation of the effectiveness of detoxification and its influence factors, which depended mainly on their mother's qualification, family atmosphere, mode and length of drug abuse, etc.
authors.affiliation: Department of Health Statistics, Kunming Medical College, Kunming 650031.
authors.forename: C
authors.initials: C
authors.lastname: Wan
authors.forename: J
authors.initials: J
authors.lastname: Fang
authors.forename: Z
authors.initials: Z
authors.lastname: He
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: He
mesh_terms: D006801:Humans; D016016:Proportional Hazards Models; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D019966:Substance-Related Disorders / Q000523:psychology / Q000628:therapy; D011795:Surveys and Questionnaires; D016019:Survival Analysis