A comparison of ultrasonic and mechanical stadiometry

Validation of portable ultrasonic stadiometers in adults

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.

Comparing the accuracy of an ultrasound height measurement device with a wooden measurement board among children aged 2-5 years in rural Lao People's Democratic Republic: A methods-comparison study

BACKGROUND

Height is a key component of nutrition assessments in children from limited-resource settings. This study aimed to assess whether handheld digital ultrasound devices for measuring children's height provide comparable accuracy to traditional measurement boards, which are bulky and difficult to transport.

METHODS

We trained 12 health workers to measure the standing height of 222 children aged 2-5 years in rural Lao People's Democratic Republic using both the ultrasound device and measurement board. The Bland-Altman method was used to depict limits of agreement and potential bias. We reported the technical error of measurement (TEM) for precision and accuracy, then assessed these results against the Standardized Monitoring and Assessment for Relief and Transition (SMART) Manual 2.0 and the WHO Multicentre Growth Reference Study (MGRS).

RESULTS

The average difference between the ultrasound and board measurements was 0.096 cm (95% limits-of-agreement: 0.041cm, 0.61cm) with a systematic bias of 0.1cm (95% confidence interval: 0.067cm, 0.134cm), suggesting the ultrasound measurements were slightly higher than those from the board. The ultrasound and board TEMs for precision were 0.157cm and 0.091cm respectively. The accuracy TEM was 0.205cm. All TEMs were within SMART and WHO MGRS limits.

CONCLUSION

The ultrasound device is comparable to the measurement board among standing Lao children aged 2-5 years for precision and accuracy TEMs but showed a bias of 0.1cm. Further studies are required to assess whether calibration can minimise this bias and determine the ultrasound's accuracy on recumbent length for infants and younger children.

Portable digital devices for paediatric height and length measurement: A scoping review and target product profile matching analysis

BACKGROUND

Routine anthropometry of children, including length/height measurement, is an essential component of paediatric clinical assessments. UNICEF has called for the accelerated development of novel, digital height/length measurement devices to improve child nutrition and growth surveillance programs. This scoping review aimed to identify all digital, portable height/length measurement devices in the literature or otherwise available internationally. We also assessed identified devices against the UNICEF Target Product Profile (TPP) to identify those of highest potential for clinical and public health use.

METHOD

We searched four databases (Medline, Embase, CINAHL and Global Health) and the grey literature between 1st January 1992 and 2nd February 2023. We looked for studies or reports on portable, digital devices for height or length measurement in children up to 18 years old. Citations were screened independently by two reviewers, with data extraction and quality assessment performed in duplicate and disagreements resolved. Devices were evaluated and scored against the 34 criteria of the UNICEF TPP.

RESULTS

Twenty studies describing twelve height/length measurement devices were identified, most of which used prospective validation designs. Additional devices were found in the grey literature, but these did not report key performance data so were not included. Across the twelve devices, only 10 of 34 UNICEF criteria on average could be fully assessed. Six met UNICEF's ideal accuracy standard and one device met the minimum accuracy standard. The Leica DistoD2 device scored highest (41%), followed by Autoanthro in a controlled environment (33%) and GLM30 (32%). These devices may be high potential for further assessment and development, though further research is required.

CONCLUSION

While 12 portable, digital devices exist for child height/length measurement, insufficient data are available to fully assess whether they meet the industry's needs. Although some devices show promise, further research is needed to test the validity of these devices in varying contexts, and continued development and commercialization will be important to improve reliability and precision of these devices for widespread use.

Reliability and Validity of an Ultrasonic Device for Measuring Height in Adults

BACKGROUND

The ultrasonic stadiometer was originally developed as a device to measure and monitor children's height. However, an ultrasonic stadiometer (InLab S50; InBody Co., Seoul, Korea) was used to measure adults' height in the 2018 Korea Community Health Survey (KCHS). This study was conducted to assess the reliability and validity of the InLab S50 in adults.

METHODS

The study subjects were 120 adults (reliability test, n=20; validity test, n=100) who had visited a health screening center. The intra- and inter-rater reliabilities of InLab S50 were assessed using the intraclass correlation coefficient (ICC). The agreement between InLab S50 and an automatic stadiometer (HM-201; Fanics, Busan, Korea) was assessed using Pearson's correlation coefficient and Bland-Altman analysis.

RESULTS

The intra- and inter-rater reliabilities of the InLab S50 were excellent (ICC=0.9999 and 0.9998, respectively). The correlation coefficient of the height measured by the two measurement devices was very high (r=0.996). The difference (Δheight [HM-201-InLab S50]) was -0.15±0.78 cm (95% limit of agreement [LOA], -1.69 to 1.38). After excluding the values outside 95% LOA, the difference was further reduced to -0.05±0.59 cm (95% LOA, -1.20 to 1.10).

CONCLUSION

This study showed that the InLab S50 is a reliable and valid device for the measurement of adults' height. Therefore, we think that InLab S50 could be used to measure adults' height in household health surveys such as the KCHS.

The accuracy of historical height loss for the detection of vertebral fractures in postmenopausal women

Historical height loss (HHL) can be calculated as the difference between a patient's tallest recalled height (TRH) and the current measured height (MH). We have examined the accuracy of HHL as a clinical test for the detection of prevalent vertebral fractures. Subjects were postmenopausal women aged 50 or older who had been referred for specialist assessment of osteoporosis risk (n=323; average age 66.0+/-9.2 years; range 50-92 years). MH was determined using a wall-mounted stadiometer. The presence of prevalent vertebral fractures was assessed by radiographic morphometry, with fracture defined as a vertebral height ratio<0.8. The positive likelihood ratio (LR+) for fracture was relatively flat until HHL>6.0 cm. With HHL from 6.1 to 8.0 cm, the LR+ was 2.8 [95% confidence interval (95%CI), 1.3, 6.0]. When HHL was >8.0 cm, the LR+ was 9.8 (95% CI, 3.0, 31.8). The area under the receiver operating characteristics curve for the ability of HHL to detect fracture was 0.66 (95% CI, 0.59, 0.72). At HHL>6.0 cm, sensitivity was 30% (95% CI, 22, 37%), and specificity was 94% (95% CI, 90, 97%). The positive predictive value was relatively low across a range of theoretical prevalence, rising above 80% only at very high prevalence rates (>50%). In contrast, the negative predictive value was high at the prevalence rates seen in most clinical practice, and dropped below 80% only when the prevalence exceeded 25%. This study shows that HHL<or=6.0 cm rules out prevalent vertebral fracture with a high degree of accuracy; patients with HHL>6.0 cm should have spine radiographs to examine for the presence of vertebral fractures.