First Field Test of an Innovative, Wider Tape to Measure Mid-Upper Arm Circumference in Young Laotian Children.

Abstract

Measurements of mid-upper arm circumference (MUAC) may result in measurement error due to incorrect placement along the arm or tight pulling of tape. To reduce the risk of these measurement errors, a new wider tape was developed. To compare the measurement agreement and precision and the ease of use of the standard and wide MUAC tapes. Mid-upper arm circumference was measured in 814 children aged 9 to 32 months with both tapes. The midpoint of the upper arm was measured with the standard tape and estimated with the wide tape. Standardization sessions were implemented to assess intra- and interobserver precision. Mid-upper arm circumference with the wide MUAC tape was significantly larger than the standard tape (mean [standard deviation]: 14.3 [1.0] cm vs 13.9 [1.0] cm; P < .001), resulting in a consistent bias of +0.41 cm. Forty-six (5.7%) children were identified with low MUAC <12.5 cm by standard tape compared with 10 (1.2%) by the wide tape ( P <.001). Because a new tape could be reproduced by correcting for this bias, we corrected measured results by subtracting 0.41 cm and mean MUAC by tape type was no longer significantly different. Intra- and interobserver technical error of measurement suggested a better precision with the wide MUAC tape. Despite simplifying the measurement by approximating the midpoint of the upper arm, the wide MUAC tape tended to have better precision than the standard MUAC tape. However, there was a consistent measurement bias of +0.41 cm in mean MUAC. This first field test yielded promising results and led to further product adjustments.