Cross-cultural Adaptation and Psychometric Validation of the World Health Organization Quality of Life-old Module (WHOQOL-OLD) for Persian-speaking Populations

Background: Reliable quality of life assessment is important for identification of health problems, evaluation of health interventions and planning of optimal health policies and care packages. Due to lack of a psychometrically robust measurement tool for quality of life appraisal among the Iranian older population, this study was aimed to investigate psychometric properties of the Persian version of the World Health Organization quality of life-old module (WHOQOL-OLD-P) for use on the Iranian and other Persian-speaking aged populations.

Methods: The standard translate/back-translate procedure was applied to convert the English version of the WHOQOL-OLD into Persian. The face and content validities were assessed by a panel of experts including 15 specialists in geriatrics and allied fields. The Cronbach's alpha and intra-class correlation (ICC) coefficients were estimated to assess internal validity and reliability of the translated version. Factorial structure of the WHOQOL-OLD-P was also tested using confirmatory factor analyses in a sample of 400 Persian-speaking older adults (aged 60 years of old and above) residing in the city of Yazd, the capital city of Yazd province, center of Iran.

Results: The internal consistency and reliability indices of the WHOQOL-OLD-P were in the vicinity of acceptable range (Cronbach's alpha: 0.65-0.82 and ICC: 0.90-0.98). The confirmatory factor analysis outputs confirmed the six-factor solution of the WHOQOL-OLD-P (RMSEA = 0.04, CFI = 0.94, TLI = 0.93, SRMR = 0.06).

Conclusion: The study findings support validity and reliability of the WHOQOL-OLD-P for use on Iranian and possibly other Persian-speaking older populations. Further cross-cultural and comparative multinational studies are recommended to provide more vigorous evidence about feasibility and acceptability of the translated tool in diverse and multicultural Persian-speaking communities.