Predictive value of different body segments to estimate height in a South African adult hospital population.

BACKGROUND AND AIMS: Height measurement is a vital component for assessing nutritional risk, and calculating dietary requirements in a clinical setting where indirect calorimetry is not available. In many patients, height cannot be measured accurately, and equations based on body segments are relied on to predict height. This study aimed to evaluate if specific body segments are better associated with height than others in a South African public hospital setting. METHODS: A descriptive cross-sectional study was conducted in three public hospitals in Bloemfontein, South Africa, on patients, 20-50 years of age, and able to stand upright without assistance to be measured by stadiometer. Spearman correlations were assessed between stadiometer height and arm-span, demi-span, ulna length, knee height, tibia length, fibula length and foot length (measured by standardised techniques). Multiple regression analysis was performed to identify the segment that is most closely associated with stadiometer height in the study population. RESULTS: The sample included 141 participants (61.7% male, median age 38.8 years; IQR: 10.1 years). All measured body segment were statistically significantly correlated with stadiometer height, the strongest association being with knee height in both males (R2:0.77) and females (R2:0.86). Foot length and ulna length had the weakest correlation with stadiometer height in males and females, respectively. Multiple regression analysis identified knee height as having the best predictive value in determining stadiometer height. Overall, measurements of lower leg segments, particularly knee height, predicted measured height better than upper body segments. CONCLUSIONS: When choosing height-prediction equations in clinical settings in populations with a high prevalence of stunting, such as South Africa, the fact that stunting affects the growth of long bones in the lower body more than in the upper body, should be considered.