title: Validation of the Korean version of the thyroid cancer-specific quality of life questionnaire.
abstract: OBJECTIVE
  The increasing incidence of thyroid cancer worldwide has drawn attention to the needs for assessing and managing health-related quality of life (HRQoL) of thyroid cancer survivors. We conducted this study to validate the Korean version of the thyroid cancer-specific quality of life (THYCA-QoL) questionnaire.
  
  
  METHODS
  Data obtained from 227 thyroid cancer survivors were analyzed using standard validity and reliability analysis techniques. Reliability was assessed by measuring internal consistency via Cronbach α coefficient, and validity was assessed by determining the Pearson correlation coefficient between the THYCA-QoL questionnaire and the following relevant assessment tools: the European Organization for Research and Treatment of Cancer QLQ-C30 (EORTC QLQ-C30), the Korean version of Brief Fatigue Inventory (BFI-K), the Korean version of Brief Encounter Psychosocial Instrument (BEPSI-K), Goldberg Short Screening Scale for Anxiety and Depression, and a nine-item Patient Health Questionnaire (PHQ-9). A multitrait scaling analysis was performed to assess each item's convergent and discriminant validity.
  
  
  RESULTS
  The reliability of the THYCA-QoL questionnaire was confirmed by Cronbach α coefficients for multiple-item scales which ranged from 0.54 (sensory) to 0.82 (psychological). Except for a single item (sexual interest), the questionnaire's validity was established by significant correlation observed between scales in the THYCA-QoL questionnaire and scales used in other assessment tools. A multitrait scaling analysis confirmed that all scales met the recommended psychometric standards.
  
  
  CONCLUSIONS
  The Korean version of the THYCA-QoL questionnaire is a reliable and valid assessment tool that can be used in combination with the EORTC QLQ-C30 to assess the HRQoL of thyroid cancer survivors in Korea.
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Youjin
authors.initials: Y
authors.lastname: Jeong
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Jaekyung
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Ah-Leum
authors.initials: AL
authors.lastname: Ahn
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Oh
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Hee-Kyung
authors.initials: HK
authors.lastname: Oh
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Dong-Yung
authors.initials: DY
authors.lastname: Cho
authors.affiliation: Department of Family Medicine, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Hyuk-Jung
authors.initials: HJ
authors.lastname: Kweon
authors.affiliation: Department of Family Surgery, Research Institute of Medical Science, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Kyoung Sik
authors.initials: KS
authors.lastname: Park
keywords: Korea; Quality of life; Thyroid neoplasms; Validity