title: EQ-5D-5L and SF-6D Utility Measures in Symptomatic benign Thyroid Nodules: Acceptability and Psychometric Evaluation.
abstract: The aim of this study was to examine the acceptability, validity, and reliability of the EuroQoL Five-Dimension Five-Level (EQ-5D-5L) and Short-Form Six-Dimension (SF-6D) health utility measures in patients with symptomatic benign thyroid nodules.
  
  
  
  Data from a randomized controlled trial (ClinicalTrials.gov identifier: NCT02398721) of 294 patients with symptomatic benign thyroid nodules were utilized for this psychometric evaluation of health-related quality of life (HR-QOL) measurement. Three HR-QOL questionnaires-the generic 12-item Short Form Health Survey (SF-12v2), EQ-5D-5L, and SF-6D-were interviewer-administered at baseline and 2 weeks afterwards. Responses to SF-6D were transformed to SF-6D utility scores using a Hong Kong population scoring algorithm derived by standard gamble, whereas responses to EQ-5D-5L were mapped onto EQ-5D-3L response via interim mapping algorithms and then converted to EQ-5D-5L utility scores using a Chinese-specific value set. Construct validity was determined by evaluating Spearman correlation between SF-12v2 scores and utility scores. Two-week test-retest reliability was assessed using intra-class correlation coefficient.
  
  
  
  No significant (>15%) floor and ceiling effects were observed for SF-6D utility scores. The SF-6D utility scores had a moderate Spearman rank correlation with the SF-12v2 domain score providing evidence for adequate construct validity. The SF-6D utility scores showed good test-retest reliability (0.794; range 0.696-0.860). Better reliability was observed in SF-6D utility scores than in EQ-5D-5L utility scores.
  
  
  
  While the EQ-5D-5L instrument was less reproducible, the SF-6D instrument appeared to be an applicable, valid, and reliable measure in assessing the HR-QOL of Chinese patients with symptomatic benign thyroid nodules. The impact of utility score selection on the effectiveness and cost effectiveness of clinical interventions targeted to these patients needs further exploration.
  
  
  
  NCT02398721, ClinicalTrials.gov.
authors.affiliation: Department of Family Medicine and Primary Care, The University of Hong Kong, 3/F Ap Lei Chau Clinic, 161 Ap Lei Chau Main Street, Ap Lei Chau, Hong Kong. carlosho@hku.hk.
authors.forename: Carlos K H
authors.identifier: http://orcid.org/0000-0002-6895-6071
authors.initials: CKH
authors.lastname: Wong
authors.affiliation: Division of Endocrine Surgery, Department of Surgery, Queen Mary Hospital, The University of Hong Kong, 102 Pokfulam Road, Pok Fu Lam, Hong Kong. blang@hku.hk.
authors.forename: Brian H H
authors.identifier: http://orcid.org/0000-0002-9362-0086
authors.initials: BHH
authors.lastname: Lang
authors.affiliation: Department of Family Medicine and Primary Care, The University of Hong Kong, 3/F Ap Lei Chau Clinic, 161 Ap Lei Chau Main Street, Ap Lei Chau, Hong Kong.
authors.forename: Hill M S
authors.initials: HMS
authors.lastname: Yu
authors.affiliation: Department of Family Medicine and Primary Care, The University of Hong Kong, 3/F Ap Lei Chau Clinic, 161 Ap Lei Chau Main Street, Ap Lei Chau, Hong Kong.
authors.forename: Cindy L K
authors.initials: CLK
authors.lastname: Lam
mesh_terms: D000328:Adult; D000368:Aged; D001007:Anxiety / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006723:Hong Kong; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008603:Mental Health; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology / Q000523:psychology; D011594:Psychometrics; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D016606:Thyroid Nodule / Q000453:epidemiology / Q000523:psychology*