Abstract
Objective: To examine the psychometric characteristics of the brief version of the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire in rural-community-dwelling older people in Taiwan using Rasch analysis. Methods: This is a cross-sectional study. A total of 1200 subjects aged 65 years were recruited to complete the 26-item WHOQOL-BREF. Scale dimensionality, item difficulty, scale reliability and separation, item targeting, item-person map, and differential item functioning (DIF) were examined. Results: The four WHOQOL-BREF scales (physical capacity, psychological well-being, social relationships, and environment) were found to be unidimensional and reliable. The item-person map for each domain indicated that the spread of the item thresholds sufficiently covered the latent trait continuum being measured. However, gaps in content coverage were identified in the social domain. Analyses of the DIF revealed that one psychological item (body image) exhibited DIF across the two age groups (old-old vs. young-old) and that two social items (sexual activity and friends' support) displayed DIF across genders and the two age groups. Conclusions: Rasch analysis is a comprehensive method of psychometric evaluation of the WHOQOL-BREF and identifies areas for improvements. Three items displaying age-related DIF (body image, sexual activity, and friends' support) may potentially cause biased health-related QOL assessments, and their impacts on scores should be carefully examined.
Original language | English (US) |
---|---|
Pages (from-to) | 605-618 |
Number of pages | 14 |
Journal | Quality of Life Research |
Volume | 18 |
Issue number | 5 |
DOIs | |
State | Published - Jun 2009 |
Funding
Acknowledgments This study was supported by the National Health Research Institutes (NHRI-EX98-9805PI and NHRI-EX95-9204PP), China Medical University (CMU96-225), and the National Science Council (NSC93-2320-B-039-013 and NSC95-2314-B-038-008) of Taiwan, Republic of China. We are most grateful to all of the subjects who participated in this study.
Keywords
- Health-related quality of life
- Item response theory
- Older people
- Rasch model
- WHOQOL-BREF
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health