Validity of the Katz Index to assess activities of daily living by informants in neuropathological studies

• Autor(a) principal: Lucena Ferretti-Rebustini, Renata Eloah de
• Data de Publicação: 2015
• Outros Autores: Abaide Balbinotti, Marcos Alencar, Jacob-Filho, Wilson, Rebustini, Flavio [UNESP], Suemoto, Claudia Kimie, Goncalves Pasqualucci, Carlos Augusto, Farfel, Jose Marcelo, Paraizo Leite, Renata Elaine, Grinberg, Lea Tenenholz, Nitrini, Ricardo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S0080-623420150000600010; http://hdl.handle.net/11449/161153
• topic: Activities of Daily Living; Aging; Proxy; Psychometrics; Validation Studies

Objective: To analyze the evidences of construct validity of the Katz Index for the retrospective assessment of activities of daily living (ADL) by informants, to assist neuropathological studies in the elderly. Method: A cross-sectional study analyzed the functional ability of ADL measure by the Katz Index, of 650 cases randomly selected from the Brazilian Brain Bank of the Ageing Brain Study Group (BBBABSG) database. Sample was divided in two subsamples for the analysis (N=325, each) and then stratified according to cognitive decline assessed by the Clinical Dementia Rating Scale (CDR). Factor analyses with calculations of internal consistency and invariance were performed. Results: Factor analysis evidenced a unidimensional instrument with optimal internal consistency, in all subgroups. Goodness of fit indices were obtained after two treatments of covariance, indicating adequacy of the scale for assessing ADL by informants. The scale is invariant to cognitive decline meaning that it can be used for subjects with or without cognitive impairment. Conclusion: Katz Index is valid for the retrospective assessment of basic ADL by informants, with optimal reliability.