Validity of the dimensional scale of social support of the Medical Outcomes Study adapted to Portuguese in the study pro-health

Estudos sobre a import??ncia de rede e apoio social nos desfechos em sa??de t??m sido desenvolvidos nos ??ltimos 30 anos. Rede social ?? definida como o grupo de pessoas com as quais o indiv??duo mant??m contato ou alguma forma de v??nculo social. Apoio social refere-se ?? funcionalidade da rede social (apoio emocional, apoio material entre outros). O presente estudo d?? continuidade ?? avalia????o das propriedades psicom??tricas da escala de apoio social utilizada em um estudo de coorte de trabalhadores de uma universidade p??blica no Rio de Janeiro - Estudo Pr??-Sa??de por meio da avalia????o de sua validade de constructo atrav??s da an??lise fatorial confirmat??ria. Essa investiga????o baseia-se nos dados de 4030 participantes obtidos na primeira fase desse estudo (1999), onde um question??rio multidimensional foi utilizado. Nesse foi inclu??da a escala de apoio social elaborada para o Medical Outcomes Study (MOS), que foi adaptada para o portugu??s, no ??mbito do estudo. Foi realizada a an??lise fatorial confirmat??ria com o intuito de avaliar os modelos com tr??s, quatro e cinco fatores quanto ao ajuste, validade convergente e validade discriminante. (...)Studies about the importance of social support on health outcomes have been developed since 30 years. Social network is defined as a group of people which a person has contact with or any kind of social connections. Social support is related to the functionality of the social network. The present study continues the psychometric testing of the social support scale, used in a cohort of public university servents of Rio de Janeiro - Pr??-Sa??de Study ??? through evaluation of the construct validity using the confirmatory factor analysis. This investigation was based on information about 4030 participants in the first stage of the study (1999), which a multidimensional instrument was used. In this study, it was included the social support scale of the Medical Outcomes Study (MOS), which was adapted to Portuguese, in the study???s environment. The confirmatory factor analysis was used to test the three, four and five factors models adjustment, the convergent and discriminant validity. The estimation method used was the WLSMV (robust weighted least squares) recommended to models with multivariate non-normal distributed indicators which is the case of the categorical indicators of the MOS social support scale. The fit indices used were the CFI (comparative fit index), the TLI (Tucker Lewis index), the RMSEA (root mean square error of approximation), the ???? statistic, and the WRMR ((weighted root mean square residual). The statistic program used was the Mplus. The four factor model was the one which presents the best goodness-of-fit measures (CFI=0,897; TLI=0,987). However, the residuals were high (RMSEA=0,131; WRMR=3,727), indicating a poor adjust. The convergent validity was good, presenting values above 0,50 of extracted variance and values above 0,70 of composed reliability in all dimensions. Only the material dimension presented good discriminant validity. In conclusion, nevertheless the four factor model presented some vantages compared with the other models, it is necessary implement changes to improve the adjust of the model. This modifications are related to itens exclusion, and not only about the dimentions addiction, which is suggested through insufficient results of the discriminant validity of that model - highly correlations in the ???information??? and ???emotional??? dimensions. A scale with a smaller numbers of itens should improve the measurements of social support and bring news conclusions in the investigations about the importance of social support in the social determinants and wellness