BackgroundAssessing quality of life (QOL) in elderly needs specific instruments. The Older People’s Quality of Life Questionnaire (OPQOL-35) is one of the common tools that used for measuring quality of life in elderly populations. The questionnaires contains 35 items tapping into eight domains including life overall, health, social relationships and participation, independence, control over life and freedom, home and neighborhood, psychological and emotional well-being, financial circumstances, culture and religion. This study aimed to translate and validate the OPQOL-35 in Iran.MethodsForward-backward procedure was applied to translate the original questionnaire from English into Persian. Then following qualitative face and content validity, a sample of elderly people completed the questionnaire. In order to evaluate the construct validity, exploratory and confirmatory factor analyses was performed. Subsequently, convergent and divergent validity of the factors were evaluated. Reliability was evaluated by performing internal consistency analysis and Intraclass Correlation Coefficients (ICC).ResultsIn all 500 older people completed the questionnaire. The mean age of participant was 68.92 (SD = 6.97) years, and mostly were males (66.6%). The result of exploratory factor analysis showed 8 factors with Eigen values of greater than one, which explained 67.4% of the variance observed. Confirmatory factor analysis showed acceptable fit indexes for the data [Comparative Fit Index (CFI) = 0.92, Minimum Discrepancy Function by Degrees of Freedom divided (CMIN/DF) = 2.832, Root Mean Square Error of Approximation (RMSEA) = 0.067]. The convergent and divergent validity did not support three latent factors (Life overall, Independence, control over life, freedom and Psychological and emotional well-being). Convergent and divergent validity shown that construct fulfilled for the health, social relationships and participation, home and neighborhood, financial circumstances, culture and religion latent factors, however the results did not support the convergent and divergent validity for three latent factors (Life overall, Independence, control over life, freedom and Psychological and emotional well-being). Cronbach’s alpha coefficient for the subscales ranged from 0.65–0.95. Test-retest reliability (ICC) of the questionnaire with two weeks interval were ranged from 0.88–0.95 indicating a good range of reliability.ConclusionThe findings suggest that the Iranian version of OPQOL-35 is a valid measure for assessing quality of life in elderly populations in different settings.Electronic supplementary materialThe online version of this article (10.1186/s12955-018-1002-z) contains supplementary material, which is available to authorized users.

BackgroundAttitudes to the aging process are affected by the individual’s sociocultural background. The measurement of this important concept among older people in various societies requires the use of tools that are able to demonstrate both reliability and validity.ObjectiveThe objectives of this study were to translate and validate the Attitudes to Aging Questionnaire (AAQ) and investigate its psychometric features among Iranian older people.MethodsIn this methodological study, the Farsi version of the AAQ was validated among 400 Iranian older adults who were members of citizen clubs in an urban area of Iran. Content, face and construct (exploratory factor analysis) validities of the AAQ were assessed. In addition, its reliability was assessed in terms of internal consistency and stability. For discriminant validity, the discriminant power of the AAQ in terms of gender and education levels was evaluated. Criterion validity showed a significant correlation between the most subscales of the AAQ and the Short Form 36 (SF-36) and World Health Organization Quality of Life (WHOQOL) questionnaires. Descriptive and inferential statistics were used for data analysis.ResultsThe exploratory factor analysis confirmed the construct validity of the AAQ. The result of the test–retest reliability with a 2-week interval was satisfactory and reported as r=0.90 (p<0.001). The Cronbach’s alpha coefficient was reported as 0.75 for the whole instrument and 0.85–0.93 for its dimensions. There were associations between the AAQ subscales, SF-36 quality of life (r=0.56, p<0.001) and WHOQOL-BREF (r=0.78, p<0.001), indicating an appropriate convergent validity. The ability to discriminate between male and female participants and those with lower and higher education levels was demonstrated, thus lending support to claims for adequate known-group validity.ConclusionThe Farsi version of the AAQ showed favorable validity and reliability. Therefore, it can be used for assessing attitudes toward aging among older adults.