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

OBJECTIVE: To evaluate the added value of the use of upper arm length (UAL) along with mid-upper arm circumference (MUAC) to diagnose and estimate the prevalence of wasting in comparison to current WHO standard and other MUAC-based methods. DESIGN: UAL and usual anthropometric measurements were collected during a national cross-sectional nutritional survey. Children were classified into three upper arm length groups (UALGs): UALG1, UALG2 and UALG3 according to the following UAL limits: ≤150, 151–180 and ≥181 mm, respectively. Receiver operating characteristic curves were used to determine the best MUAC cut-off for each group using weight-for-height Z-score (WHZ) as a reference standard. Wasting prevalence, sensitivity and specificity of all diagnostic methods were compared. SETTING: This study was conducted in Mauritania. PARTICIPANTS: National representative sample of children from 6 to 59 months old. RESULTS: In total, 12 590 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 mm 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 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.