Validation of portable ultrasonic stadiometers in adults

Abstract

Background: Over the past two decades, alternatives to measuring standing stature using portable devices based on innovative technologies have been explored. This study aimed to assess the validity of three portable ultrasonic stadiometers for measuring unstretched standing stature in comparison to a portable floor-standing mechanical stadiometer in Brazilian adults.

Methods: Cross-sectional study carried out with a convenience sample of 115 individuals (51.3 % women) with a mean age of 31.5 ± 9.3 years and able to stand independently. The portable ultrasonic stadiometers Avanutri®, Balmak® and Inbody® were compared to the portable mechanical floor-standing stadiometer Avanutri®, which was treated as a reference, to measure unstretched standing stature. Differences between mechanical and ultrasonic stadiometers were analyzed by paired-sample t-tests with 95 % confidence intervals (95 % CI). Furthermore, the equivalence level was assessed using the Two One-Sided Test (TOST) procedure.

Results: Statistically equivalent absolute mean differences were observed in the comparative analysis between the stadiometers. The Avanutri® and Balmak® ultrasonic stadiometers produced significant systematic bias of 0.79 cm (95%CI: 0.471; 1.116) and 0.40 cm (95%CI: 0.084; 0.715), respectively. The Inbody® ultrasonic stadiometer produced a systematic bias of -0.03 cm (95%CI: -0.291; 0.229), below the 1 mm limit.

Conclusion: The Inbody® portable ultrasonic stadiometer demonstrated validity for accurately measuring standing stature in Brazilian adults.

Keywords: Anthropometry; Body height; Nutritional assessment; Stature; Ultrasonic device.