Validação de equações para estimativa de peso em idosos hospitalizados e institucionalizados

Abstract

INTRODUCTION: Having the elderlies body weigh measure is extreme important, not only for nutritional evaluation, but also to other clinical situations as medicine dose calculi, ventilatory volume among others. However, It is not Always possible to obtain, because patient related issues (as immobility syndrome that is relatively common in the elderly population) and resources issues (absence of a scale or bed body weight measurements dispositive). Rosa, in her theses developed eight equations to estimate body weight in the Brazilian hospitalized elderlies, evolving from one to eight measurements. However, they were not validated. Objective: To validate body weight estimative equations in the elderlies. Methods: For that, was realized as cross-sectional study from diagnostic accuracy. Participated at the study hospitalized and institutionalized elderlies. The variable investigated were: age, gender, measured weight (scale), estimated weight (obtained from 20 different equations) and anthropometric measurements (height, knee height, demi spam, head truncus length, arm length, abdominal circumference, arm , thigh, calf, fist, hip, thorax, neck and waist circumference, subscapular , abdominal and tricciptal fold that are on the 20 equations that are going to be analyzed). The data were digitized on Excel and then analyzed with SPSS software version 21.0. To statistic analyzes. On the descriptive stage, the variables were presented per frequency (Absolut and relative), medium, standard deviation and minimum and maximum values. To analyze the relation between weight obtained by the equations were used the Intraclass correlation coefficient and it’s respective confidence interval (CI 95%). The matching pattern between the measurements was classified according to Fleiss-Cohen in null homogeneity (CCI < 0,31) , mediocre ( CCI 0,31-0,51), medium ( CCI > 0,51 – 0,71) , good (CCI > 0,71 -0,91) and excellent ( CCI > 0,91-1,0). The equations with (1) ICC> 0.710, (2) IC95% with lower distance between the lower and upper limits were considered applicable, and (3) smaller mean difference and smaller amplitude of the concordance limit in the Bland Altman plot. Results: Were analyzed 191 elderlies between 60-98 year, most institutionalized ( n=110), female ( n=113) and that could walk ( n=114). In the hospitalized elderlies, the Intraclass correlation coefficient (confidence interval 95% CI= 95% medium difference= d) from Rosa’s equations from I to VIII in relation to the measured body were, 0,817 (IC95%=0,730-0,879; d=0,63), 0,856 (IC95%=0,773-0,909; d=-1,89), 0,921 (IC95%=0,880-0,948; d=-0,43), 0,934 (IC95%=0,899-0,957; d=-0,48), 0,942 (IC95%=0,912-0,963; d=-0,12), 0,926 (IC95%=0,835-0,962; d=-2,08), 0,941 (IC95%=0,899-0,964; d=-1,34) e 0,950 (IC95%=0,899-0,964; d=1,12). In the institutionalized elderlies the coefficients (IC95%, difference from the media) were respectively, 0,831 (IC95%=0,452-0,957; d=-5,56), 0,832 (IC95%=0,547-0,920; d=5,04), 0,891 (IC95%=0,393-0,962; d=5,12), 0,972 (IC95%=0,951-0,983; d=1,38), 0,974 (IC95%=0,946-0,986; d=1,56), 0,994 (IC95%=0,375-0,984; d=4,08), 0,893 (IC95%=-0,13- 0,973; d=6,56) e 0,896 (IC95%=-0,012- 0,974; d=6,48). Conclusion: All the eight body weight estimative equations of Rosa's obtained a good to excellent classification in hospitalized and institutionalized elderly, with the IV and V equations showing the best performance in both scenarios. Finally, it is recommended to use the equation IV because it involves a minor number of anthropometric measures.