Validity and accuracy of the Guedes Tool for the evaluation of informal social support for older adults

Abstract

The objective of the present study was to confirm the validity of the Guedes Tool, an instrument for assessing informal social support (ISS) for older adults, and to estimate its accuracy. Confirmatory factor analysis (CFA) was performed with the CFI and RMSEA indexes and the chi-square relationship (X2) with degrees of freedom (gl). For the analysis of accuracy, the area under the ROC curve, sensitivity ​​(S) and specificity (SP) values, positive predictive value (PV+), negative predictive value (PV-) and the Younder’s J Index (J) were verified to confirm the best cut-off point. Data collection was carried out with older adults from Natal and metropolitan region in 2018. The inclusion criteria were: be 60 years old or older, with preserved cognitive levels. Two hundred and six older adults participated in the CFA study and 197 participated in the accuracy analysis. The estimates of the indexes evaluated in the CFA were: X2/gl =1.33, RMSEA=0.04 (95% CI 0.025-0.054) and CFI=0.91. The ROC curve obtained an area of ​​0.78 (CI95: 0.72-0.85; p<0.001) for the determination of older adults with low ISS. The highest value J was 0.44 for a score ≤34, with an S value of 59.76% and an SP value of 84.96%. The instrument presented a well-adjusted model with four dimensions, according to CFA criteria. It had a good area under the ROC curve and good to moderate S and SP values for the cutoff value of 34 points or less, for the diagnosis of insufficient ISS. Good PV+ and PV- indicators confirmed the desirable levels of accuracy of the tool.

Keywords:
Social Support; Health of the Elderly; Validation Study; Factor Analysis; Statistical; Data Accuracy