Weighing Vietnamese children: how accurate are child weights adjusted for estimates of clothing weight?

Children who are weighed for growth monitoring are frequently clothed, especially in the cold weather. Health workers commonly estimate and subtract the weight of these clothes, but the accuracy of these estimates is unknown. We assessed the accuracy of child weights adjusted for estimated clothing typical of hot, cold, and extremely cold ambient temperatures. Trained field workers weighed a sample of 212 children 6 to 42 months old from the ViSION project, adjusted the weights using a job aid describing the weights of common clothing by season and age, and then weighed the clothing to calculate the actual clothing and child weights. Fieldworker estimates of the weight of the clothing that children wore during weighing were remarkably good. In nearly all cases (207 of 212; 97.7%), the difference between the estimated and actual clothing weight was less than the precision of the child scales (+/- 50 g), and most (181 of 212; 84.5%) were within 25 g. Thus, the calculated child weights were, in fact, equivalent to the actual child weights. Using simulations, we found that improperly accounting for clothing weight can overestimate weight-for-age by 0.1 to 0.4 Z score. Accurate weights are possible, even under adverse conditions. Our training methods, clothing album, and job aid might benefit nutrition research and programming in Viet Nam as well as settings with colder climates.