101. A new look at the WHOQOL as health-related quality of life instrument among visually impaired people using Rasch analysis
- Author
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Vijaya K. Gothwal, Srinivas Marmamula, and Gullapalli N Rao
- Subjects
Adult ,Male ,medicine.medical_specialty ,Psychometrics ,Visually impaired ,Health Status ,Visual impairment ,Visual Acuity ,India ,Vision, Low ,Dysfunctional family ,World Health Organization ,Physical medicine and rehabilitation ,Quality of life ,Sickness Impact Profile ,Surveys and Questionnaires ,medicine ,Humans ,Reliability (statistics) ,Aged ,Health related quality of life ,Rasch model ,Public health ,Public Health, Environmental and Occupational Health ,Reproducibility of Results ,Middle Aged ,humanities ,Cross-Sectional Studies ,Quality of Life ,Female ,medicine.symptom ,Psychology ,Visually Impaired Persons ,Clinical psychology - Abstract
To examine the psychometric characteristics of the World Health Organization Quality of Life instrument—modified Indian version (modified WHOQOL) and its subscales in adults with visual impairment (VI) using Rasch analysis. Cross-sectional data were of people aged ≥40 years with VI (n = 1,333) who responded to the modified WHOQOL in the Andhra Pradesh Eye Disease Study, India. Rasch analysis was used to explore the instrument and its subscales for key indices such as measurement precision by person separation reliability, PSR (i.e., discrimination between strata of participants’ health-related QOL [HRQOL], recommended minimum value 0.8), unidimensionality (i.e., measurement of a single construct), and targeting (i.e., matching of item difficulty to participants’ HRQOL). Rasch-guided iterative approach including category re-organization to enable threshold ordering and item deletion to overcome multidimensionality resulted in a unidimensional 9-item WHOQOL and a 6-item level of independence (LOI) subscale with adequate PSR (0.81 and 0.82, respectively). Targeting was sub-optimal for both (−1.58 logits for WHOQOL and −2.55 logits for the subscale). Remaining subscales were dysfunctional. The WHOQOL and LOI subscale can be improved and shortened, and the Rasch-revised versions are likely to assess the HROQL of VI patients best because of their brevity, reliability, and unidimensionality.
- Published
- 2012