title: Estimation of health-related-quality of life depends on which utility measure is selected for patients with carpal tunnel syndrome.
abstract: METHODS
  Cross-sectional.
  
  
  BACKGROUND
  Carpal tunnel syndrome (CTS) refers to the compression neuropathy of the median nerve at the wrist.
  
  
  OBJECTIVE
  To establish the interinstrument reliability, convergent construct validity, and the levels of agreement of health utility indexes 2 and 3 (HUI-2 and HUI-3), EuroQol 5-dimensions (EQ-5D), EuroQol-visual analog scale (EQ-VAS) and to determine the difference of these utility measures based on age and gender in patients with carpal tunnel syndrome.
  
  
  METHODS
  Seventy-four patients with a confirmed diagnosis of carpal tunnel syndrome completed the 3 questionnaires and EQ-VAS a month before surgery. Demographic characteristics were reported. Intraclass correlation coefficients were used to assess relative interinstrument reliability. Pearson correlation coefficients (r) were used to establish convergent construct validity. Bland-Altman plots and t tests were used to describe the levels of agreement between the 4 utility measures. A 2-way analysis of variance was performed to determine the effect of age and gender on the utility measures; HUI-2, HUI-3, and EQ-5D.
  
  
  RESULTS
  The intraclass correlation coefficients were 0.85 for HUI-3 vs HUI-2 and 0.80 for HUI-2 vs EQ-VAS. Pearson correlation coefficients ranged from 0.60 to 0.89; HUI-3 vs HUI-2: 0.89, and HUI-3 vs EQ-5D: 0.60. One-sample t test demonstrated significant differences between HUI-3 vs HUI-2, HUI-3 vs EQ-5D, and HUI-3 vs EQ-VAS measures, with mean differences of -0.12, -0.15, and -0.14, respectively. A 2-way analysis of variance test controlling for age and gender indicated neither as predictors of outcome scores.
  
  
  CONCLUSIONS
  The HUI-3 vs HUI-2 and HUI-2 vs EQ-VAS demonstrated excellent interinstrument relative reliability measures. The HUI-3 vs HUI-2 displayed very strong convergent construct validity measures, and strong validity measures were established between the remaining utility measures. In addition, the pair-wise utility comparisons demonstrated minimal bias between HUI-2 vs EQ-5D, HUI-2 vs EQ-VAS, and EQ-VAS vs EQ-5D measures.
  
  
  CONCLUSIONS
  N/A.
  
  
  METHODS
  N/A.
authors.affiliation: School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada. Electronic address: nazarigs@mcmaster.ca.
authors.forename: Goris
authors.initials: G
authors.lastname: Nazari
authors.affiliation: School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Joy C
authors.initials: JC
authors.lastname: MacDermid
authors.affiliation: Division of Plastic Surgery, MacHANd, McMaster Medical Centre/Hamilton Health Sciences, Hamilton, Ontario, Canada.
authors.forename: James
authors.initials: J
authors.lastname: Bain
authors.affiliation: Division of Plastic Surgery, St. Joseph's Healthcare, Hamilton, Ontario, Canada.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Levis
authors.affiliation: Division of Plastic Surgery, MacHANd, Hamilton, Ontario, Canada.
authors.forename: Achilleas
authors.initials: A
authors.lastname: Thoma
keywords: Carpal tunnel syndrome; Euro-Qol; Health utility indexes; Health-related quality of life