Factor structure for the frailty syndrome was consistent across Europe

Objectives: We explored the measurement properties of frailty with the goal of optimizing frailty assessment according to phenotype definition of Fried and comparing measurement properties across countries. Study Design and Setting: Data are from the Survey of Health, Ageing and Retirement in Europe (n = 27,938), a population-based study of community-dwelling adults aged >= 50 years. Frailty was specified as a unidimensional construct, and measurement invariance across the 12 countries was tested. To assess our measurement model, we used confirmatory factor analysis (CFA) and multigroup CFA to assess measurement invariance. Results: The unidimensional model fit the data well (adjusted chi(2)(48) = 82.74, P = 0.001), and the same structure was satisfactory for all countries. Inclusion of equality constraints led to significant model deterioration (adjusted chi(2)diff(88) = 995.05, P < 0.001), suggesting differences in parameters across countries. Spain was removed from further analyses, and equality constraints for Greece, Sweden, Israel, Italy, and France were not tenable. Accounting for these led to satisfactory model fit (adjusted chi(2)(113) = 414.33, P < 0.001). Significant mean frailty differences were identified. Conclusion: The relationships between the construct of frailty and indicators, although broadly constant, do vary across some countries. Furthermore, there was evidence of differing levels of frailty for the middle-aged and older populations across European countries. (C) 2014 Elsevier Inc. All rights reserved.