title: Validity and reliability of the SF-36 questionnaire in patients on the waiting list for a kidney transplant and transplant patients.
abstract: OBJECTIVE
  The aim of this study is to explore the validity and reliability of the health-related quality of life SF-36 questionnaire in patients undergoing renal replacement therapy.
  
  
  METHODS
  A multicenter descriptive transversal study was carried out in Galicia, Spain, with patients undergoing renal replacement therapy. The tool used to measure the health-related quality of life was the authorized Spanish version of the 'SF-36' generic health questionnaire. The internal consistency of this survey was determined by means of interscale correlations and Cronbach's alpha statistic. Validity was examined with a principal component exploratory factor analysis with Varimax rotation.
  
  
  RESULTS
  A total of 213 patients waiting for a kidney transplant and 72 recipients with a functioning renal transplant were studied. All the interscale correlations were positive and significant. The overall statistical value for Cronbach's alpha was equal to 0.91 (95% CI: 0.91-0.94) and in all domains this value ranged from 0.7 to 0.92. The factor analysis identified 8 factors that explain 66.6% of the variance, 5 of which consisted of the same structure as 5 factors (domains) of the theoretical model.
  
  
  CONCLUSIONS
  The SF-36 questionnaire is also a reliable and valid tool when used to measure the quality of life of patients undergoing renal replacement therapy.
authors.affiliation: Juan Canalejo Hospital, A Coruña, Spain. immaculada.gomez.besteiro@sergas.es
authors.forename: M Inmaculada
authors.initials: MI
authors.lastname: Gómez-Besteiro
authors.forename: M Isolina
authors.initials: MI
authors.lastname: Santiago-Pérez
authors.forename: Angel
authors.initials: A
authors.lastname: Alonso-Hernández
authors.forename: Francisco
authors.initials: F
authors.lastname: Valdés-Cañedo
authors.forename: Pablo
authors.initials: P
authors.lastname: Rebollo-Alvarez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D014850:Waiting Lists