Knowledge about dietary fibres (KADF): development and validation of an evaluation instrument through structural equation modelling (SEM)

Objectives: Because there is scientific evidence that an appropriate intake of dietary fibre should be part of a healthy diet, given its importance in promoting health, the present study aimed to develop and validate an instrument to evaluate the knowledge of the general population about dietary fibres. Study design: The present study was a cross sectional study. Methods: The methodological study of psychometric validation was conducted with 6010 participants, residing in ten countries from 3 continents. The instrument is a questionnaire of self-response, aimed at collecting information on knowledge about food fibres. For exploratory factor analysis (EFA) was chosen the analysis of the main components using varimax orthogonal rotation and eigenvalues greater than 1. In confirmatory factor analysis by structural equation modelling (SEM) was considered the covariance matrix and adopted the Maximum Likelihood Estimation algorithm for parameter estimation. Results: Exploratory factor analysis retained two factors. The first was called Dietary Fibre and Promotion of Health (DFPH) and included 7 questions that explained 33.94 % of total variance ( = 0.852). The second was named Sources of Dietary Fibre (SDF) and included 4 questions that explained 22.46% of total variance ( = 0.786). The model was tested by SEM giving a final solution with four questions in each factor. This model showed a very good fit in practically all the indexes considered, except for the ratio 2/df. The values of average variance extracted (0.458 and 0.483) demonstrate the existence of convergent validity; the results also prove the existence of discriminant validity of the factors (r2 = 0.028) and finally good internal consistency was confirmed by the values of composite reliability (0.854 and 0.787). Conclusions: This study allowed validating the KADF scale, increasing the degree of confidence in the information obtained through this instrument in this and in future studies.

Measuring attachment to life in old age: the Portuguese version of the Positive Valuation of Life Scale (Positive VOL)

Purpose This study aims to present the psychometric properties of the Portuguese version of the Positive Valuation of Life Scale (Lawton et al. in J Aging Ment Healt 13:3–31, 2001). Method Sample included 207 community-dwelling elders (129 women; MAge = 77.2 years, SD = 7.5). The data collection included the translated and adapted Portuguese version of Positive Valuation of Life Scale, Life Satisfac- tion Index Z, Meaning in Life Questionnaire and Geriatric Depression Scale. Results From exploratory factor analysis, two factors emerged, existential beliefs and perceived control, ex- plaining 49 % of the total variance. Both factors were positively related with meaning in life and life satisfaction and negatively related with depression (p\0.05). The values obtained for internal consistency for the total scale and for each subscale were good (a [ 0.75). Conclusion The Portuguese version of Positive VOL Scale represents a reliable and valid measure to capture the subjective experience of attachment to one’s life. The two-factor structure is an update to Lawton’s previous work and in line with findings obtained in the USA (Dennis et al. in What is valuation of life for frail community-dwelling older adults: factor structure and criterion validity of the VOL, Thomas Jefferson University, Center for Applied Research on Aging and Health Research, 2005) and Japan (Nakagawa et al. in Shinrigaku Kenkyu 84:37–46, 2013). Future research is required to investigate VOL predictors and the potential changes toward the end of the life span.

Validação do questionário Roma III para o diagnóstico de dispepsia funcional em adultos portugueses

Introdução: A validação de instrumentos é essencial na investigação epidemiológica, especialmente para a definição consensual de caso e comparação de resultados. Atualmente, o instrumento mais utilizado para identificar a dispepsia funcional é o questionário Roma III, o qual não se encontra validado para a população portuguesa. Objetivos: Validar o questionário Roma III para dispepsia funcional em adultos Portugueses. Métodos: O questionário foi traduzido seguindo as recomendações de Roma III. Um total de 166 indivíduos responderam ao questionário. A identificação da categoria dispepsia funcional em adultos baseou-se em um ou mais sintomas dos 4 sintomas que a escala permite avaliar através de 6 itens. A consistência interna, reprodutibilidade e análise de conteúdo foram avaliados com recurso ao SPSS 23.0. Resultados: O coeficiente de alfa de Cronbach no total dos 18 itens avaliados foi de 0.89. Para a categoria dispepsia funcional (avaliada através de 6 itens) foi de 0.76 e o alfa de Cronbach com base em itens padronizados foi de 0.85. Conclusões: validamos, para Portugal, o Questionário Roma III para o diagnóstico de doenças gastrointestinais funcionais, designadamente para a categoria dispepsia funcional em adultos. Estes resultados sugerem que este instrumento será útil para a investigação na população Portuguesa.