Construct validity of the Questionnaire for Older Senior Citizens based on a confirmatory factor analysis: A study during the period of self‐restraint to prevent the spread of coronavirus disease 2019.

Aim: This study aims to clarify the construct and criterion‐related validity of the Questionnaire for Older Senior Citizens (QO) during the COVID‐19 pandemic. Methods: This cross‐sectional study was conducted in Japan between November 11, 2020 and January 10, 2021. Of the 1645 (63.5%) older adults who responded, data from 900 participants were analyzed. First, we conducted an exploratory factor analysis (EFA) among older‐older adults (aged ≥75 years) and extracted the factors. Next, we conducted a confirmatory factor analysis (CFA) using structural equation modeling. We also conducted this analysis among younger‐older adults (aged ≥65 and <75 years) using the same model. Moreover, we compared each item of the QO with frailty status. Results: Results of the EFA revealed six factors: social conditions and lifestyle, subjective conditions, cognitive functions, physical activity, oral functions, and physical functions. The results of the CFA were as follows: comparative fit index (CFI) = 0.971, adjusted goodness of fit index (AGFI) = 0.978, root mean square error of approximation (RMSEA) = 0.018, and standardized root mean square residual (SRMR) = 0.030. The results among the younger‐older adults were as follows: CFI = 0.880, AGFI = 0.940, RMSEA = 0.037, and SRMR = 0.048. Many QO items were significantly associated with frailty (P < 0.05). Conclusions: Among the older‐older adults group, the model used for the QO has sufficient suitability and construct validity; among the younger‐older adults group, there also is sufficient questionnaire suitability. Moreover, the QO has criterion related validity with frailty. Geriatr Gerontol Int 2021; 21: 1018–1025. [ABSTRACT FROM AUTHOR]