Background: Cross-culturally adapted questionnaires may not be comparable to their original version. Objects: To examine concurrent validity of two health-related quality of life (HRQOL) instruments for the Korean versions of EuroQOL-5 Dimension (EQ-5D) and the abbreviated version of the World Health Organization Quality of Life (WHOQOL-BREF) instrument. Methods: A total of 139 cancer survivors from two rehabilitation institutes was recruited. All participants were registered for palliative rehabilitation care. Both instruments were concurrently administered by health care providers following the second bout of the rehabilitation cares. Rasch partial credit model and Spearman’s correlation analysis were used to investigate: 1) dimensionality, 2) hierarchical item difficulty, and 3) concurrent validity using correlations between two instruments. Results: For the WHOQOL-BREF, all items except negative feeling, pain, dependence of medical aid, were found to be acceptable, while all items of EQ-5D were acceptable. There was an evidence of negative correlations between EQ-5D and 4 domains of WHOQOL-BREF. Two correlations were strong (EQ-5D vs. physical health domain, ρ = –0.610, 95% CI = –0.716 to –0.475) and moderate (EQ-5D vs. psychosocial domain, ρ = –0.402, 95% CI = –0.546 to –0.236). Other two correlations were weak (EQ-5D vs. social relationship and environmental domains, ρ = –0.242, 95% CI = –0.401 to –0.075 and ρ = –0.364, 95% CI = –0.514 to –0.207, respectively). Item difficulty calibrations of the two measurements were ranged from –0.84 to 0.86 for the EQ-5D and –1.07 to 1.06 for the WHOQOL-BREF. Conclusion: The study provides some supports for the concurrent validity of the two Korean versions of HRQOL instrument, with evidences of weak to strong correlations between the EQ- 5D and four domains of the WHOQOL-BREF applied to various cancer survivors. Additionally, the cancer survivors appeared to have more of a tendency to view the EQ-5D items as being slightly more challenging than the WHOQOL-BREF items.

Background: Although the original version of the health-related quality of life (HRQOL) questionnaires are found to be acceptable, the cross-culturally adapted versions may not be comparable to their original version. Objects: To examine dimensionality and construct validity of two Korean versions of the brief version of the World Health Organization Quality of Life (WHOQOL-BREF) and EuroQOL-5 dimension (EQ-5D) questionnaires. Methods: A total of 77 cancer survivors undergoing palliative rehabilitation programs from two rehabilitation institutes was recruited from April 16, 2018 to June 26, 2019. The WHOQOL- BREF and the EQ-5D were filled out by the various cancer survivors following a particular session of rehabilitation programs. The scores were analyzed with Winsteps Rasch analysis computer program using the rating scale model. Rasch fit statistics were used to determine the dimensionality and the item difficulty calibrations of WHOQOL-BREF and EQ-5D. Results: All items except two, negative feeling, need treatment function and pain prevent activity (mean square [MnSq] = 2.42, 1.82 and 2.51, respectively), were found to be acceptable, while two items of the EQ-5D, anxiety/depression and self-care, were misfit (infit MnSq = 1.65 and 0.38, respectively). Item difficulty calibrations of WHOQOL-BREF match person ability measures (i.e., HRQOL) fairly well. However, the person ability distribution showed obvious ceiling effects for EQ-5D. All items of EQ-5D were appeared to be less challenged in comparison with those of WHOQOL-BREF. Conclusion: Item-level analysis using the Rasch model supports the quality of culturally adapted items used to measure the HRQOL one exception; that is, whether or not to include misfit items as part of the HRQOL measurements. Additionally, cancer survivors undergoing palliative rehabilitation programs appear to have more of a tendency to view the EQ-5D items as being more challenging than the WHOQOL-BREF.

목적 : EuroQoL (EQ-5D)를 이용하여 나이관련황반변성 (age-related macular degeneration, AMD) 환자 들의 삶의 질을 평가하고자 하였다. 방법 : 2008~2012년도 국민건강영양조사 자료를 이용하였으며, 안과 검진을 받은 40세 이상 총 18007명을 대상으로 하였다. 나이관련황반변성은 무산동 안저촬영을 통하여 초기(early)와 후기(late)로 분류하였다. 건강관련 삶의 질은 ‘EQ-5D’ 척도를 사용하여 다섯 가지(운동능력, 자기관리, 평소활동, 통증·불편, 불안·우울)로 측정하였고, 공변량을 보정한 다중 로지스틱 회귀분석을 시행하여 나이관련 황반변성과 건강관련 삶의 질의 연관성을 평가하였다. 결과 : 나이관련 황반변성 환자들의 평균 나이는 초기와 말기에서 각각 64.98±0.39세와 65.97±1.35세로 대조군 (54.31±0.14세)에 비하여 유의하게 높았다(p<0.001). 초기 나이관련황반변성의 경우 연령, 성별, 거주지, 교육, 직업, 흡연, 음주, 운동, 비만, 당뇨, 그리고 고혈압을 보정한 후에도 대조군에 비해 불안·우울을 느끼는 위험이 1.42배(95% 신뢰구간: 1.051.93) 높았으며, 후기 나이관련황반변성의 경우 연령, 성별, 교육, 직업, 흡연, 그리고 고혈압을 보정한 후에도 대조군에 비해 자기관리에 어려움을 느낄 위험이 3.74배(95% 신뢰구간: 1.0214.07) 높았다. 결론 : 나이관련황반변성은 건강관련 삶의 질과 연관성이 있었으며, 나이관련황반변성이 환자들의 시력뿐만 아니라 건강과 복지와 같은 더 넓은 범위에 영향을 미칠 수 있으므로 안과적 치료와 함께 정신적인 지지가 중요할 것으로 생각된다.