Psychometric properties of the EUROHIS-QOL 8-item index (WHOQOL-8) in a Brazilian sample

Objective: To test the psychometric properties of the EUROHIS-QOL 8-item index in a Brazilian sample. Methods: The sample consisted of 151 patients and 174 healthy controls (n=325). Several psychometric properties were tested. Results: Reliability showed good internal consistency (Cronbach's alpha = 0.81). The measure showed good discriminant validity between patients and healthy controls (mean1 = 3.32, SD1 = 0.70; mean2 = 3.77, SD2 = 0.63, t = 6.12, p < 0.001). Convergent validity showed significant correlations (p < 0.001) between the EUROHIS-QOL 8-item index and all domains of the WHOQOL-Bref (overall r = 0.47; general health r = 0.54; physical r = 0.69; psychological r = 0.62; social relationship r = 0.55; environment r = 0.55) and between the EUROHIS-QOL 8-item index and the domains of the SF-36, except for the social domain (p = 0.38). On Rasch analysis of unidimensionality, general fit measures showed adequate performance. The EUROHIS-QOL 8-item index also showed good fit on confirmatory factor analysis (CFA) (chi-square = 18.46, degrees of freedom [df] = 15; comparative fit index [CFI] = 0.99; root mean square error of approximation [RMSEA] = 0.03; goodness of fit index [gfi] = 0.99; root mean square residual [RMR] = 0.03; p = 24). Conclusion: The EUROHIS-QOL 8-item index showed good psychometric properties. It is a reliable quality of life measure that can be used in Brazilian populations.

Brazilian WHOQOL-OLD Module version: a Rasch analysis of a new instrument

OBJECTIVE: To evaluate the Brazilian version of WHOQOL-OLD Module and to test potential changes to the instrument to increase its psychometric adequacy. METHODS: A total of 424 older adults living in a city in Southern Brazil completed the WHOQOL-OLD instrument, in 2005. Rasch analysis was used to explore the psychometric performance of the scale, as implemented by the RUMM2020 software. Item-trait interaction, threshold disorders, presence of differential item functioning and item fit, were analyzed. RESULTS: Two ("death and dying" and "sensory abilities") out of six domains showed inadequate item-trait interactions. Rescoring the response scale and deleting the most misperforming items led to scale improvement. The evaluation of domains and items individually showed that the "intimacy" domain does perform well in contrast to the findings using the classical approach. In addition, the "sensory abilities" domain does not derive an interval measure in its current format. CONCLUSIONS: Unidimensionality and local independence were seen in all domains. Changes in the response scale and deletion of problematic items improved the scale's performance.

OBJETIVO: Analisar a versão brasileira do Módulo WHOQOL-OLD, indicando alterações potenciais do instrumento para aumentar a adequação psicométrica. MÉTODOS: O total de 424 idosos residentes em Porto Alegre, RS, responderam o instrumento WHOQOL-OLD em 2005. O modelo de Rasch foi utilizado para a análise do desempenho psicométrico da escala, a partir do software RUMM2020. Foram analisadas a interação item-traço, a presença de funcionamento diferencial dos itens e a adequação dos itens ao modelo de Rasch. RESULTADOS: Dois domínios ("morte e morrer" e "funcionamento do sensório") apresentaram interação item-total insuficiente. Remodelar a escala de resposta e excluir itens com pior performance resultou em melhora da escala. A análise dos domínios e itens individualmente foi capaz de indicar que o domínio "intimidade" teve boa performance, ao contrário dos resultados gerados pela abordagem psicométrica clássica. O domínio "funcionamento dos sentidos" não fornece uma medida intervalar em seu formato atual. CONCLUSÕES: Todos os domínios apresentaram unidimensionalidade e independência local. As alterações na escala de resposta e a exclusão de itens problemáticos determinaram melhora da performance da escala.