title: Quality of life in cancer patients in South Asia: psychometric properties of the Sinhala version of the EORTC QLQ-C30 in cancer patients with heterogeneous diagnoses.
abstract: BACKGROUND
  The European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30) was evaluated for its psychometric properties in a sample of cancer patients from the culturally distinct South Asian subcontinent, which accounts for a significant proportion of the global cancer burden.
  
  
  METHODS
  Psychometric testing assessed the hypothesised scale structure, internal consistency, content and construct validity, and acceptability of the Sinhala version of the QLQ-C30 independently in two heterogeneous groups of cancer patients at pretreatment (N = 489) and during treatment (N = 343).
  
  
  RESULTS
  Qualitative feedback from an expert panel assessing content validity recommended measuring family support during illness as an additional, culturally-relevant dimension of health-related quality of life (HRQL). Compliance was high (100%), with little missing data (0.11%). Multitrait scaling results supported the scale structure of the QLQ-C30, with the exception of the cognitive functioning scale, which was also the only scale that did not meet the 0.70 internal consistency criteria in either sample. Interscale correlations were of a moderate size, with conceptually related scales showing higher correlations. All scales were able to discriminate clearly between pre- and current treatment patients (P < 0.01), although results were less consistent when comparing groups formed on the basis of age and disease stage.
  
  
  CONCLUSIONS
  Overall psychometric results confirmed the QLQ-C30 as a reliable and valid questionnaire for assessing HRQL of cancer patients in Sri Lanka.
authors.affiliation: Epidemiology Unit, Ministry of Health, No 231, De Saram Place, Colombo 10, Sri Lanka. hja@unimelb.edu.au
authors.forename: Harindra
authors.initials: H
authors.lastname: Jayasekara
authors.forename: Lalini C
authors.initials: LC
authors.lastname: Rajapaksa
authors.forename: Neil K
authors.initials: NK
authors.lastname: Aaronson
mesh_terms: D000328:Adult; D000368:Aged; D001208:Asia; D003430:Cross-Sectional Studies; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis*; D011594:Psychometrics; D011788:Quality of Life; D011795:Surveys and Questionnaires