Estimation of stature in adults: development and validation of a new predictive formula using the Tibiale Mediale-Sphyrion Tibiale length

Abstract Introduction: Several regression equations for estimating stature have been used by health professionals in the clinical, nutritional, and forensic practice. However, there is a lack of standardization when taking measures and further population-specific equations are needed. We aimed to develop and validate an equation to estimate stature in adult population using the International Society for the Advancement of Kinanthropometry (ISAK)-standardized measurement Tibiale Mediale-Sphyrion Tibiale (TMST) length. Methodology: A total of 188 Colombian adult women and men (23.1(4.0) years; 165.0(8.5) cm; 62.6(11.5) kg; 22.9(3.0) kg·m-2) participated in this STROBE-based cross-sectional study. Body mass, stature and TMST length were measured according to the ISAK protocol. Participants were randomly assigned to either the equation development group (n=81) or validation group (n=107). The new predictive equation of stature was derived by multiple linear regression analysis using TMST length, age and sex as predictors. Intraclass correlation coefficient (ICC) and Bland-Altman analysis were performed to assess agreement between the real and estimated stature. Results: The selected predictive equation of stature (R2=0.851; SEE=4.36 cm) did not include the age since this variable did not have statistical influence on the results: 117.156 - (6.245 x Sex) + (1.482 x TMST); sex = 0 for men and 1 for women. ICC (95%CI) of 0.851 (0.788, 0.896) was obtained. The 95% limits-of-agreement between real and estimated stature ranged from 7.00 to -10.28 cm (bias -1.64 cm). Conclusions: This new formula represents an ISAK-standardized, low-cost, and easy-to-apply method to estimate stature in population with mobility limitations (hospitalized, injured athletes, etc.) or in forensic anthropology. However, further external validation is needed.