title: An international field study of the reliability and validity of a disease-specific questionnaire module (the QLQ-MY20) in assessing the quality of life of patients with multiple myeloma.
abstract: OBJECTIVE
  To test the reliability, validity and sensitivity of the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-MY24 questionnaire, designed to assess the quality of life of myeloma patients with the QLQ-C30.
  
  
  METHODS
  The study was carried out through the EORTC Quality of Life Group using clinical trials in seven countries. All trials used the QLQ-C30 and QLQ-MY24 at baseline and a follow-up timepoint.
  
  
  RESULTS
  Two hundred and forty patients participated. The questionnaires were acceptable to patients. The hypothesised scale structure (disease symptoms, side-effects, body image and future perspective) was confirmed by multi-trait scaling, internal consistency and correlation analysis. Most scales demonstrated sensitivity to change and discriminated between clinically different patients. The social support scale (4 items) was removed due to observed ceiling effects.
  
  
  CONCLUSIONS
  The final questionnaire contains 20 items, QLQ-MY20, and is a reliable and valid instrument recommended for use with the QLQ-C30 in myeloma patients.
authors.affiliation: Clinical Trials Research Unit, University of Leeds, 17 Springfield Mount, Leeds LS2 9NG, UK. k.cocks@leeds.ac.uk
authors.forename: K
authors.initials: K
authors.lastname: Cocks
authors.forename: D
authors.initials: D
authors.lastname: Cohen
authors.forename: F
authors.initials: F
authors.lastname: Wisløff
authors.forename: O
authors.initials: O
authors.lastname: Sezer
authors.forename: S
authors.initials: S
authors.lastname: Lee
authors.forename: E
authors.initials: E
authors.lastname: Hippe
authors.forename: P
authors.initials: P
authors.lastname: Gimsing
authors.forename: I
authors.initials: I
authors.lastname: Turesson
authors.forename: R
authors.initials: R
authors.lastname: Hajek
authors.forename: A
authors.initials: A
authors.lastname: Smith
authors.forename: L
authors.initials: L
authors.lastname: Graham
authors.forename: A
authors.initials: A
authors.lastname: Phillips
authors.forename: M
authors.initials: M
authors.lastname: Stead
authors.forename: G
authors.initials: G
authors.lastname: Velikova
authors.forename: J
authors.initials: J
authors.lastname: Brown
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000523:psychology*; D010349:Patient Compliance; D011446:Prospective Studies; D011788:Quality of Life; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires / Q000592:standards*