[Precision and accuracy of body weight assessment in hospitalized adults].
BACKGROUND
Body weight (BW) is widely used to evaluate and manage clinical situations therefore assessment errors can influence the ichosen therapies.


OBJECTIVE
To assess the variability in values of BW obtained by using different equipment (weight scales).


METHODS
A cross sectional study was performed to assess BW of 360 adult patients in eight units including clinical and surgical specialties Three types of scales were used: a portable domestic model and a fixed platform model, both from the units and a portable digital model previously calibrated and used as standard reference equipment. Self-reported weight (SRW) was also compared to weight assessed with the reference equipment. The values were compared trough paired-samples t-test using SPSS software.


RESULTS
The difference between weights assessed by the reference equipment and SRW was 445+/-3.359 g (P=0.015), it was -182+/-2.323 g (P=0.140) for portable domestic scales and 137+/-2.412 g (P=0.218) for platform fixed scales. Values obtained from SRW, portable domestic scales and fixed platform scales were strongly correlated to the mean value of weight assessed by the reference equipment (r=0.973, r=0.987 and r=0.986, respectively). Nevertheless, considering analyses of each patient, errors of magnitude greater than 500 g occurred in 78.8% of SRW, 80.6% of the portable domestic scales and 40% of the fixed platform scales.


CONCLUSIONS
In general, the scales tested were neither accurate nor precise for measuring BW, considering the percentage of error in the evaluation of each patient and the variability observed.
Beghetto
Mariur Gomes
MG
Hospital de Clínicas de Porto Alegre, Porto Alegre, RS.
Assis
Michelli Cristina Silva de
MC
Luft
Vivian Cristine
VC
Mello
Elza Daniel de
ED
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001835:Body Weight; D001837:Body Weights and Measures / Q000295:instrumentation*; D003430:Cross-Sectional Studies; D006760:Hospitalization; D006801:Humans; D008875:Middle Aged; D015203:Reproducibility of Results