PS3-20 APPLICABILITY AND PSYCHOMETRIC EVALUATION OF UTILITY AND CANCER-SPECIFIC HEALTH-RELATED QUALITY OF LIFE MEASURES IN PATIENTS WITH INCIDENTAL THYROID NODULES

Tuesday, June 14, 2016
Exhibition Space (30 Euston Square)
Poster Board # PS3-20

Carlos King Ho Wong, PhD, Department of Family Medicine and Primary Care, The University of Hong Kong, Hong Kong Island, Hong Kong and Brian Hung Hin Lang, MD, Department of Surgery, The University of Hong Kong, Hong Kong Island, Hong Kong
Purpose: The aim of this study was to examine the acceptability, validity and reliability of utility measures and cancer-specific health-related quality of life (HRQOL) in Chinese patients diagnosed with incidental thyroid nodules.

Method(s): Data from a randomized controlled trial (ClinicalTrials.gov Identifier: NCT02398721) of 314 patients diagnosed with incidental thyroid nodules were utilized for this psychometric evaluation of HRQOL measurement. Three HRQOL questionnaires, cancer-specific Functional Assessment of Cancer Therapy-general (FACT-G) and generic 12-item Short Form Health Survey (SF-12v2) and 6-item Short Form Health Survey (SF-6D), were administered through face-to-face interviews at both baseline and 2-week after baseline. Responses to SF-6D were transformed to SF-6D utility scores using Hong Kong standard gamble value set. Construct validity was determined by evaluating the extent to overlap SF-12v2 dimensions across HRQOL instruments by Spearman rank correlation. Internal consistency and 2-week test-retest reliability was assessed using Cronbach’s α coefficient and intra-class correlation coefficient, respectively.

Result(s): No significant (>15%) floor and ceiling effects were observed for FACT-G subscale and total scores. The SF-6D utility scores and FACT-G subscale scores had a moderate Spearman rank correlation with the corresponding SF-12v2 domain score that conceptually measures the similar construct providing evidence for adequate construct validity. Internal consistency of the FACT-G subscales and total scales were acceptable (α: 0.639-0.850) for all subscales aside from the Emotional well-being subscale (α: 0.581). The HRQOL and utility scores showed excellent test-retest reliability (range: 0.758-0.858).

Conclusion(s): The SF-6D utility score and cancer-specific FACT-G questionnaire appears to be a valid and reliable measure to assess the HRQOL of Chinese patients diagnosed with incidental thyroid nodules, and thus evaluate the treatment response to those patients.