title: Development and validation of the general module of the system of quality of life instruments for chronic diseases and its comparison with SF-36.
abstract: BACKGROUND
  Quality of life (QOL) for patients is now a worldwide concern, but there are few specific instruments developed by modular approach to measure outcomes in chronic diseases.
  
  
  OBJECTIVE
  This study aimed to develop and validate the System of Quality of Life Instruments for Chronic Diseases--General Module (QLICD-GM).
  
  
  METHODS
  Based on the World Health Organization's definition of QOL and programmed decision procedures, the QLICD-GM was developed using focus group discussions, pilot tests of 201 cases, and field tests of 620 cases representing seven different chronic diseases. The number of items in the final version was reduced to 30 from a 73-item pool, and the psychometric properties of the scale were evaluated by indicators, such as validity and reliability coefficients, standardized response mean, and statistical methods of correlational analysis, t-tests, and structural equation modeling.
  
  
  RESULTS
  Correlational and structural equation model analyses confirmed good construct validity with root mean square error of approximation of 0.0606, nonnormed fit index of 0.941, and comparative fit index of 0.947. Test-retest reliability coefficients for all domains and facets were higher than 0.70, with a range of 0.71-0.92, and the internal consistency alphas for most domains and facets were higher than 0.65 (ranging from 0.52 to 0.89). All domains and overall scores of the QLICD-GM had a statistically significant change after treatment, with moderate effect size.
  
  
  CONCLUSIONS
  The QLICD-GM has good validity, reliability, and better responsiveness compared with the SF-36® Health Survey and can be used as the general module for chronic diseases.
authors.affiliation: School of Humanities and Management, Guangdong Medical College, Dongguan, Guangdong, People's Republic of China. wanchh@hotmail.com
authors.forename: Chonghua
authors.initials: C
authors.lastname: Wan
authors.forename: Xin
authors.initials: X
authors.lastname: Tu
authors.forename: Susan
authors.initials: S
authors.lastname: Messing
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Li
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yang
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.forename: Yuping
authors.initials: Y
authors.lastname: Yang
authors.forename: Jiahua
authors.initials: J
authors.lastname: Pan
authors.forename: Zengfen
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease / Q000523:psychology*; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires