P185 - POTENTIAL OF ALTERNATIVE ARM MEASUREMENTS TO PREDICT HEIGHT OF ADULT AMBULATORY PATIENTS

P185

POTENTIAL OF ALTERNATIVE ARM MEASUREMENTS TO PREDICT HEIGHT OF ADULT AMBULATORY PATIENTS

R. Blaauw^1,*, T. M. Esterhuizen², F. Blankenberg¹

¹Human Nutrition, ²Epidemiology and Biostatistics, Stellenbosch University, Cape Town, South Africa

Rationale: Alternative height prediction techniques are needed because infirmity or physical impairment may limit the ability to obtain accurate height measurements. This study aimed to evaluate and compare alternative methods to measure or predict the height of ambulatory adult patients in relation to the reference test (gold standard-stature measured by a vertical stadiometer).

Methods: The diagnostic accuracy study recruited 221 adult inpatients who were able to stand upright without assistance. Stadiometer Height (SH) (reference test) was compared with the following index tests: Half Arm Span (HAS), Total Arm Span (TAS), Demi span (DS) and Ulna Length (UL). Standardised methodology and conversion formulae were used. The reference and index tests were compared via paired t-tests and correlation analysis. Agreement between methods was assessed by Bland-Altman (BA) plots and reported as mean difference (MD) and limits of agreement (upper limit ; lower limit).

Results: The study population, mean age 39.9±13.54 years, majority females (n=119, 52,9%), had a mean height, measured through stadiometer height, of 164.52±8.46cm. This differed significantly (p<0.001) from height obtained through HAS (170.51±10.46cm); TAS (171.06±10.3cm); UL (169.91±7.52cm), but not significantly from DS (164.23±7.26cm, p=0.553). Strong correlations were found between the reference test and index tests (HAS r=0.88; TAS r=0.90; UL r=0.80; DS r=0.61). BA plots showed good agreement for DS with stadiometer height (MD=0.28cm, 14.10;-13.54), with large bias and imprecision for HAS (MD=-6cm, 4.29;-16.28); TAS (MD=-6.62cm, 1.89;-15.13) and UL (MD=-5.41cm, 4.72;-15.55).

Conclusion: Although DS measurements showed the smallest bias compared to reference test, the large limits of agreement indicate poor precision. The other tests produced inaccurate results.

Disclosure of Interest: None declared