Psychometric properties of the Dutch WHOQOL-OLD.

BACKGROUND: To assess the internal consistency reliability and construct validity of the Dutch version of the World Health Organization Quality of Life Instrument-Older Adults Module (WHOQOL-OLD).

METHODS: The psychometric properties of the Dutch WHOQOL-OLD were examined in a cross-sectional study using a sample of 1,340 people aged 60 years or older. Participants completed a Web-based questionnaire, the 'Senioren Barometer'. Reliability was evaluated using Cronbach's alpha and corrected item-total correlations. Construct validity of the Dutch WHOQOL-OLD was evaluated with confirmatory factor analyses, and correlations within and between scales, using scales WHOQOL-BREF, Short Form Health Survey (SF-12), Tilburg Frailty Indicator (TFI), and the Emotional and Social Loneliness Scale (ESLS).

RESULTS: The reliabilities of the six WHOQOL-OLD facets or subscales were sufficient to good (.66-.91). The convergent validity of the WHOQOL-OLD was good, whereas our findings on the divergent validity of the WHOQOL-OLD were somewhat mixed. Findings corroborating the divergent validity were that the 6-factor model fitted better than the second-order factor model, and WHOQOL-OLD facets sensory abilities, past, present and future activities, death and dying, intimacy correlated more strongly with similar than dissimilar scales. Not fully supporting divergent validity were the extremely high correlations between the factors corresponding to autonomy, past, present and future activities, and social participation.

CONCLUSION: We offer Dutch healthcare and social workers an instrument with good psychometric properties for measuring quality of life in older people. Further research on interrelations between WHOQOL-OLD facets is recommended.