Abstract
Background: The Personal Wellbeing Index-Adults (PWI-A) is the most widely used instrument for measuring subjective-quality of life (QoL). The current study seeks to investigate the construct validity and reliability of the Arabic version of the PWI-A on adults with bilateral hearing impairment by comparing the single-factor solution with the two-factor solution.
Methods: A cross-sectional study was conducted at the Audio-Vestibular Medicine Unit of Alexandria University from July-2017 to January-2018. A total of 205 adults were interviewed to measure the subjective-QoL using the PWI-A instrument. Internal consistency was determined using both Cronbach’s alpha and composite reliability (CR). Validity was assessed by construct validity, including ordinal regression, ordinal exploratory factor analysis (OEFA), and ordinal confirmatory factor analysis (OCFA).
Results: The first four items of the PWI-A which are: satisfaction with living standard, health, achievements, and relationships were the most important indicators of subjective-wellbeing (Part r2 0.0547, 0.0324, 0.0361, and 0.0225, respectively). OEFA suggested that the two-factor model contributes better than the single-factor model. OCFA validated this suggested solution; (two-factor: RMSEA=0.084 (90% CI=0.01-0.14); CFI=0.964; AIC=52.64; single-factor: RMSEA=0.119 (90% CI=0.07-0.17); CFI=0.922; AIC=62.77). Good internal consistency was also presented (two-factor: Cronbach’s alpha=0.719, 0.693; single-factor: Cronbach’s alpha = 0.750).
Conclusion: The Arabic version of the PWI-A is a multidimensional scale that consists of two dimensions: the first is related to subjective-QoL, and the second is related to satisfaction with the community. Thus, it is recommended to use the short version of the PWI-A with only four items to measure subjective-QoL, as it achieved sufficient reliability and construct validity.