Validation of Height-for-Age and BMI-for-Age Z-scores Assessment Using Android-Based Mobile Apps

The WHO's standards for analysis and presentation of anthropometric data is widely recognized as the best system. This study was aimed to assess the agreement of calculation of height-for-age and BMI-for-age Z-scores according to WHO growth charts using of two randomly selected mobile apps in two cohorts of European and Asian subjects. In 1,347 adolescents aged 13 to 17 years, boys and girls, living in St. Petersburg, Northwest of the Russia (European cohort, 663 subjects) and Nukus, Uzbekistan (Asian cohort 684 subjects) measured body weight and stature. Each child's height-for-age Z-score and BMI-for-age Z-scores were calculated based on WHO Child Growth Standards PC version WHO AntroPlus software and mobile applications. It was performed a Blend-Altman analysis to assess the consistency of Z-scores calculated using WHO AntroPlus software and two mobile apps. The results of the evaluation of the consistency of height-for-age and BMI-for-age Z-scores obtained using WHO AntroPlus software and mobile applications showed that Android-based mobile applications systematically overestimate Z-scores. However, this error is much smaller than any clinically significant deviations of the physical development evaluation parameters both in the European and Asian cohort volunteers. Thus, it can be claimed that it is possible to use Android-based mobile applications for growth monitoring and BMI and WHO AntroPlus software for children from 5 to 19. This is especially relevant to the need for «field» monitoring of children's growth and development performed by general practitioners visiting patients at home.