Mid-upper arm circumference tapes and measurement discrepancies: time to standardise
This is a summary of the following paper: Rana R, Barthorp H, McGrath M et al, et al (2021). Mid-upper arm circumference tapes and measurement discrepancies: time to standardize product specifications and reporting. Global Health: Science and Practice, 9(4): 1011. Available at: https://doi.org/10.9745/GHSP-D-21-00273
Community-based management of acute malnutrition has been revolutionary in increasing the coverage of treatment for wasting in children 6-59 months of age. Early and effective case identification at the community-level through the measurement of mid-upper arm circumference (MUAC) taken with MUAC tapes has been critical to this success.
Alerted by programming experiences in Ethiopia, this article demonstrates how using MUAC tapes of different designs produces different measurements. In comparing two commonly used MUAC tapes, a 2 mm error was found, which excludes 27% of “true” cases with a true MUAC of less than 115 mm. Consequently, using tapes of different thicknesses without accounting for these in the tape design, introduces a systematic bias in case identification. This may impact whether or not a child is eligible for treatment, potentially excluding at-risk children from receiving care. In addition, since research does not currently report on the MUAC tapes used, this may have implications on the validation of current thresholds used to identify malnutrition.
In a call to action, the authors make a number of recommendations to ensure common design specifications and standardised reporting, to ensure all eligible at-risk children have an equal chance of being identified for timely, appropriate treatment. These include: (1) using a fixed thickness of MUAC tape; (2) shifting of the ruler to account for different thicknesses should they be used; (3) incorporating calibration checks as standard practice when MUAC tapes are used; (4) documenting which tapes are used in all future work; and (5) a broader examination of the potential implications of these findings for current MUAC thresholds.