Paediatric weight estimation by staff during initial assessment
Research type
Research Study
Full title
The estimation of paediatric weight by emergency department staff, and a comparison with existing weight estimation strategies; a prospective study
IRAS ID
350747
Contact name
Laura Edwards
Contact email
Sponsor organisation
University of Nottingham
Duration of Study in the UK
0 years, 2 months, 1 days
Research summary
The estimation of paediatric weight is frequently performed in emergency departments when patients are too unwell to allow for objective measurement using scales. There are multiple proposed strategies for this, generally using the patient's age, height/length, or objective/subjective measures of body habitus. All published strategies have weaknesses, and none are perfectly accurate.
Paediatric staff are experienced in measuring patients' weights, and we suspect they may be more accurate in estimating patient weights than published formulae.
Staff will estimate patients' weights prior to weighing them, or reviewing any prior weights. We will capture this and patient's age and assess triage staff accuracy in weight estimation in comparison to existing published strategies.
The choice of published strategies against which the accuracy will be compared will depend upon a concurrent literature review; at minimum to include the modified/"New" APLS formula and the Luscombe formula.
Summary of Results
An accurate measurement of weight is critical for many paediatric interventions. In emergency settings, however, weighing a child is not always possible. As such, an accurate weight estimate is essential. Although age-based formulae are frequently used, they're often inaccurate and can be cognitively demanding under pressure. Given their routine experience in weighing children, we hypothesised that paediatric emergency department nurses can visually estimate a child's weight with sufficient accuracy.This study aimed to determine the accuracy of nurse estimation, by paediatric nurses, in comparison to current age-based formulae. Nurses were observed during their routine triage duties and asked to estimate the patient's weight. The patient's age, observed weight, and estimated weight was recorded in an excel spreadsheet.
Age-based weight estimations were calculated using the traditional and updated advanced paediatric life support formulae (APLS), Best Guess and Luscombe formulae. Agreement between nurse estimates and actual weights was analysed assessed with a Bland Altman plot. A modified Bland Altman plot illustrating the change in percentage error over the observed weight was constructed. A student's paired t-test was performed to determine statistical significance and 95% confidence intervals. Furthermore, the percentage of estimates within 10% and 20% of the observed weight was calculated, as measures of accuracy. Statistical analyses, excluding Bland Altman plots, were repeated for each estimation method across the age groups required by each estimation formula. A benchmark of 70% of estimates within 10% of the observed weight was considered sufficiently accurate, in accordance with previous literature.
All weight estimation tools were insufficiently accurate, overall. However, within the 6-12 years of age group, nurse estimation was sufficiently accurate, with 81% of estimates being within 10%. In contrast, updated APLS was very inaccurate despite its continued use in the UK. As such, nurse estimation could replace the use of updated APLS in children over 6.
REC name
London - Riverside Research Ethics Committee
REC reference
25/PR/0101
Date of REC Opinion
20 Feb 2025
REC opinion
Further Information Favourable Opinion