Upper arm length along with mid-upper arm circumference to enhance wasting prevalence estimation and diagnosis : sensitivity and specificity in 6 to 59 month-old children.

Objective: To evaluate the added value of the use of upper arm length (UAL) along with MUAC (mid-upper arm circumference) to diagnose and estimate the prevalence of wasting in comparison to current WHO standard and others MUAC based methods. Design: We included UAL to usual anthropometric measurements during a Mauritanian national 6-59-month-old cross-sectional nutritional survey. Children were classified into 3 groups UALG1, UALG2 and UALG3 according to the following UAL limits: ≤ 150 mm, 151-180, and > 180mm respectively. We used a Receiver Operating Characteristic curve to determine the best MUAC cut-off for each group with weight-for-height Z score as a reference standard. We compared the wasting prevalence, sensitivity, and specificity, of all diagnostic methods. Findings: In total, 12 619 children were included in the study. Wasting prevalence was 16.1%, 5.0% and 12.5% when diagnosed by WHZ < -2, MUAC < 125 mm and MUAC-UALG methods respectively. Using the MUAC-UALG method increased the sensitivity for wasting diagnosis from 17.98 % with MUAC < 125 mm to 39.43% with MUAC-UALG. The specificity decreased from 97.49% with MUAC < 125 to 92.71% with MUAC-UALG. With MUAC-height Z score and MUAC < 138 mm, sensitivity was 26.04% and 69.76%and specificity were 97.40%and 75.64% respectively. Conclusion: This alternative method using MUAC measuring tape to measure UAL increases the wasting diagnosis accuracy and allows for a better estimation of wasting prevalence. This method could be used as a potential alternative method for quick surveys in emergency settings such as Corona virus disease 2019 context.