Reliability and validity of the questionnaire to determine the biosocial rhythms of daily living in the disabled elderly

The questionnaire to determine the biosocial rhythms of daily living in the disabled elderly was newly developed. This questionnaire was aimed to evaluate a state of synchronization of biological rhythms in the disabled elderly. Eighteen items of the questionnaire relating to the synchronization of biological rhythms were finally selected by the test-retest method that was conducted for 68 disabled elderly living in a community with a duration of one year. The factor analysis showed that the questionnaire consisted of five factors: outdoor activities, ultradian rhythms, subjective evaluation of health status, social support, and sleep habits. The cumulative contribution rate of five factors was 53.2%. Reliability of the questionnaire was confirmed by a calculation of the Equal-length Spearman-Brown coefficients ranging from 0.60 to 0.80. Regarding the construct validity of the questionnaire, results of factor analysis showed five factors that were consistent with the synchronizers known in chronobiology. The total score of the questionnaire was significantly correlated to Barthel Index score and the competence score, suggesting that it partly reflects the activities of daily living of the disabled elderly. We conclude that a new questionnaire to determine the biosocial rhythm of daily living in the disabled elderly is useful to evaluate the biosocial synchronization of the disabled elderly because of its high reliability and validity.