Reliability of Measurements Performed by Community-Drawn Anthropometrists from Rural Ethiopia

Undernutrition is an important risk factor for childhood mortality, and remains a major problem facing many developing countries. Millennium Development Goal 1 calls for a reduction in underweight children, implemented through a variety of interventions. To adequately judge the impact of these interventions, it is important to know the reproducibility of the main indicators for undernutrition. In this study, we trained individuals from rural communities in Ethiopia in anthropometry techniques and measured intra- and inter-observer reliability.We trained 6 individuals without prior anthropometry experience to perform weight, height, and middle upper arm circumference (MUAC) measurements. Two anthropometry teams were dispatched to 18 communities in rural Ethiopia and measurements performed on all consenting pre-school children. Anthropometry teams performed a second independent measurement on a convenience sample of children in order to assess intra-anthropometrist reliability. Both teams measured the same children in 2 villages to assess inter-anthropometrist reliability. We calculated several metrics of measurement reproducibility, including the technical error of measurement (TEM) and relative TEM. In total, anthropometry teams performed measurements on 606 pre-school children, 84 of which had repeat measurements performed by the same team, and 89 of which had measurements performed by both teams. Intra-anthropometrist TEM (and relative TEM) were 0.35 cm (0.35%) for height, 0.05 kg (0.39%) for weight, and 0.18 cm (1.27%) for MUAC. Corresponding values for inter-anthropometrist reliability were 0.67 cm (0.75%) for height, 0.09 kg (0.79%) for weight, and 0.22 kg (1.53%) for MUAC. Inter-anthropometrist measurement error was greater for smaller children than for larger children.Measurements of height and weight were more reproducible than measurements of MUAC and measurements of larger children were more reliable than those for smaller children. Community-drawn anthropometrists can provide reliable measurements that could be used to assess the impact of interventions for childhood undernutrition

Reliability of measurements performed by community-drawn anthropometrists from rural Ethiopia.

BackgroundUndernutrition is an important risk factor for childhood mortality, and remains a major problem facing many developing countries. Millennium Development Goal 1 calls for a reduction in underweight children, implemented through a variety of interventions. To adequately judge the impact of these interventions, it is important to know the reproducibility of the main indicators for undernutrition. In this study, we trained individuals from rural communities in Ethiopia in anthropometry techniques and measured intra- and inter-observer reliability.Methods and findingsWe trained 6 individuals without prior anthropometry experience to perform weight, height, and middle upper arm circumference (MUAC) measurements. Two anthropometry teams were dispatched to 18 communities in rural Ethiopia and measurements performed on all consenting pre-school children. Anthropometry teams performed a second independent measurement on a convenience sample of children in order to assess intra-anthropometrist reliability. Both teams measured the same children in 2 villages to assess inter-anthropometrist reliability. We calculated several metrics of measurement reproducibility, including the technical error of measurement (TEM) and relative TEM. In total, anthropometry teams performed measurements on 606 pre-school children, 84 of which had repeat measurements performed by the same team, and 89 of which had measurements performed by both teams. Intra-anthropometrist TEM (and relative TEM) were 0.35 cm (0.35%) for height, 0.05 kg (0.39%) for weight, and 0.18 cm (1.27%) for MUAC. Corresponding values for inter-anthropometrist reliability were 0.67 cm (0.75%) for height, 0.09 kg (0.79%) for weight, and 0.22 kg (1.53%) for MUAC. Inter-anthropometrist measurement error was greater for smaller children than for larger children.ConclusionMeasurements of height and weight were more reproducible than measurements of MUAC and measurements of larger children were more reliable than those for smaller children. Community-drawn anthropometrists can provide reliable measurements that could be used to assess the impact of interventions for childhood undernutrition

Intra-anthropometrist reliability for repeated measurements of 84 children in rural Ethiopia.

<p>Reliability calculations are shown separately for each of the 3 measurers in the study, and also using aggregated data from all 3 measurers.</p><p>TEM = technical error of measurement; %TEM = relative TEM; ICC = intraclass correlation coefficient; MUAC = middle upper arm circumference.</p

Inter-anthropometrist reliability of height measurements compared to length measurements.

<p>Inter-anthropometrist reliability of height measurements compared to length measurements.</p

Terminal digit preference.

<p>The proportion of recorded measurements with each of the 10 possible terminal digits, shown for height (white) and MUAC (grey) measurements for (A) anthropometrist 1 and (B) anthropometrist 2. Error bars represent 95% confidence intervals, accounting for the clustered study design.</p

Reproducibility of scales in field conditions.

<p>Graphs show (A) the 9.0 kg test weight and (B) the 4.5 kg test weight, over the 10 days of the study. The 2 different scales are depicted in black or grey, and the 2 different test weight sets are depicted as dashed or solid lines. Test weights were measured after every 10^th child of the day, represented as a hash mark on the x-axis. Discontinuities in the lines indicate that the anthropometry team examined less children than the other team.</p

Inter-anthropometrist reliability for repeated measurements of 89 children, stratified by quartile of measurement.

<p>TEM = technical error of measurement; %TEM = relative TEM.</p

Inter-observer reliability for simultaneous measurements of 594 children in rural Ethiopia.

<p>TEM = technical error of measurement; %TEM = relative TEM; ICC = intraclass correlation coefficient; MUAC = middle upper arm circumference.</p

Inter-anthropometrist reliability for repeated measurements of 89 children in rural Ethiopia.

<p>TEM = technical error of measurement; %TEM = relative TEM; ICC = intraclass correlation coefficient; MUAC = middle upper arm circumference.</p

Bland-Altman plots depicting intra-anthropometrist agreement.

<p>Plots shown for measurements of (A) height, (B) weight, and (C) middle upper arm circumference in 84 children aged 0–5 years in a community-based study in Ethiopia. The solid horizontal line represents the mean percent difference between the measurements, and the dashed lines represent the 95% limits of agreement.</p