Agreement of body weight of older adults measured on digital chair scale and mechanical platform scale

Abstract

Objective The aim of the study was to evaluate the agreement between the weight of older adults measured on a chair scale and a platform scale. Methods This is a cross-sectional study. We evaluated 131 older adults (?60 years old), walk-in patients, admitted to a university hospital. Weight was measured on a digital chair scale model MS5811 (Charder® brand) and after on a mechanical platform scale (Filizola® brand). For the agreement analysis, the intraclass correlation coefficient and the Bland-Altman plot were used. Results Most of the sample consisted of males individuals (57.3%; n= 75). The average age was 70.47±7.59 years (60-96 years old). Measured by both methods, weight showed normal distribution. The average weight measured was 67.99±14.03 kg on the chair scale and 68.04±14.02 kg on the platform scale. The intraclass correlation coefficient of weight measured by the two methods was 1.00 (IC95%=1.00-1.00; p<0.001). In the Bland-Altman plot, the mean bias for the weight measured on the chair scale and the platform scale was 0.049 (IC95%=-0.011 to 0.110; p=0.1084). Conclusions The agreement between the weight measured on a chair scale and on a platform scale was almost excellent. Thus, the chair scale can be used as an alternative method of measuring weight, especially in the older adults with postural instability, mobility restrictions or immobility syndrome.