Novel weight estimation equation for children with cerebral palsy in low‐resource settings: Validation in a population‐based cohort.

Aim: To validate a novel equation to estimate weight from mid‐upper arm circumference (MUAC) among children with cerebral palsy (CP) in rural Bangladesh. Method: Children with CP aged 2 to 18 years registered in the Bangladesh CP Register were randomly selected. Data on sociodemographics, Gross Motor Function Classification System level, and anthropometric measurements were extracted. Bland–Altman plots with a 95% agreement limit and Lin's concordance correlation coefficient with 95% confidence intervals (CI) were reported to measure agreement between observed and estimated weight. Percentage error was used to determinate the method's accuracy. Results: There were 497 participants with a mean age at assessment of 9 years (SD 4 years 11 months) (47.7% female). Lin's concordance correlation coefficient between the observed and estimated weights was 0.90 (95% CI 0.89–0.92). Bland–Altman plots showed a reasonable accuracy of the equation in the study cohort. The mean percentage error of the equation was 5.04%. The average difference between observed and estimated weights was −1.02 kg (SD 5.1). The differences between observed and estimated weights were significantly greater among children with weight‐for‐age, height‐for‐age, or BMI‐for‐age z‐scores less than or equal to −4. Interpretation: It is possible to predict the weight of children with CP from MUAC with sufficient accuracy. The equation can be used for populations in low‐resources and low‐ and middle‐income countries. What this paper adds: The equations predict the weight of children with cerebral palsy from their mid‐upper arm circumference reasonably accurately.The difference between observed and estimated weights ranged between 0 kg and ± 5 kg in 81.5% of children.Sex and Gross Motor Function Classification System level did not affect the accuracy of the equations.The equations were less accurate for estimating the weight of severely undernourished children. What this paper adds: The equations predict the weight of children with cerebral palsy from their mid‐upper arm circumference reasonably accurately.The difference between observed and estimated weights ranged between 0 kg and ± 5 kg in 81.5% of children.Sex and Gross Motor Function Classification System level did not affect the accuracy of the equations.The equations were less accurate for estimating the weight of severely undernourished children. [ABSTRACT FROM AUTHOR]