Psychometric Properties of the Persian Version of the Quality of Life in Early Old Age (CASP- 19)

Abstract

Background: Today, improving the quality of life for the elderly is of great importance. In addition, creating a favorable environment for the elderly has become a common concern worldwide. Objectives: The aim of this study was to assess the psychometric properties of the Persian version of quality of life (CASP- 19) in older people. Methods: The study included 200 participants. The CASP-19 quality of life instrument for older people was adapted to Persian language through a translation and translation-back procedure. Afterwards, the reliability (internal consistency and test-retest) and validity (including face validity, content validity, factor analysis, known groups, and criterion validity), through assessing the correlation between the Persian version of the CASP-19 and the SF-36, were measured. Results: Based on internal consistency (Cronbach > s α), the reliability for CASP-19 was 0.97 and for the four subscales varied from 0.93 to 0.97. Test-retest reliability (Pearson’s correlation coefficient) for the Farsi version of the CASP-19 ranged from 0.87 to 0.94. Evaluation of discriminant validity indicated the discriminant power of the CASP-19 in terms of the presence or absence of curtailment of personal autonomy. Criterion validity indicated a significant correlation between many dimensions of the CASP-19 and the SF-36. Conclusions: This study confirmed the validity of the CASP-19 in terms of construct, convergent, known groups, and face validity. Besides, it showed an acceptable internal consistency. The CASP-19 is valid for investigating the needs of the Iranian elderly.