Pediatrics/original researchEstimating the Weight of Children in Kenya: Do the Broselow Tape and Age-Based Formulas Measure Up?
Introduction
When clinicians resuscitate children, it is paramount that they know or can accurately estimate the child's weight. This information allows them to administer proper medication doses, determine defibrillation energy, and use equipment of the correct size. Because delaying a resuscitation to weigh a child is impractical, it is important to have an accurate method to estimate weights. Two commonly used methods are age-based formulas and the Broselow tape,1, 2 which uses height-to-weight correlations to predict weight and provides corresponding predetermined medication dosages and equipment sizes. Because calculation of medication dosages has been shown to be a significant source of medical error,3, 4, 5 the Broselow tape can alleviate stress surrounding pediatric resuscitation and reduce adverse drug events.6, 7
Broselow height-based weight estimation has been validated in several developed countries (Table 1).1, 2, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23 The majority of these studies suggest that the Broselow tape is still useful for estimating weight of children. Recent studies, however, show that as obesity rates increase, the Broselow tape may be underestimating weights; these studies have small sample size and therefore will require further investigation to determine whether this trend is real. Conversely, the utility of these methods in developing countries where malnutrition is prevalent is not well studied. Only 3 studies have been performed in middle-income developing countries; no studies exist for low-income countries, to the authors' knowledge (Table 1).24, 25, 26 The 3 studies conducted in middle-income developing countries have conflicting results: A South African and Indian study reported the Broselow tape to be valid, whereas another study in India reported overestimation of weights by more than 10%.24, 25, 26 This implies that validated methods for weight estimation among pediatric populations in developed nations may not transfer to developing nations in which higher rates of malnutrition and an increased burden of morbidity and mortality caused by infectious diseases are prevalent. This highlights the need for further study in low-income developing countries, which are among the most resource-limited settings in the world. Among resource-limited settings, children living in sub-Saharan Africa are among those with the highest rates of malnutrition and diseases such as HIV.27 Because, to our knowledge, there are no published studies validating weight estimation methods in these pediatric populations, it is important to ascertain what methods of pediatric weight estimation, if any, are valid in sub-Saharan Africa.
Kenya is one such country in sub-Saharan Africa in which children face high morbidity from malnutrition and wasting diseases such as tuberculosis and HIV and for which pediatric resuscitation procedures have seldom been validated. According to experiential evidence, most clinicians in Kenya estimate weights with age-based formulas. Problems with these formulas arise when caregivers are unsure of the child's age, which is common in Kenya. Additionally, malnutrition is prevalent in Kenya. These children often have a low weight for age.28 As malnutrition becomes chronic, children have a diminished height for age as well, making them appear more normally proportioned.29 As a result, approximately 35% of children younger than 5 years are stunted because of malnutrition.28 Therefore, given that many Kenyan children are overall smaller for age, height-based estimates, such as the Broselow tape, may be better at estimating weights than age-based formulas. Our objective was to assess the validity of the Broselow tape and age-based formulas for the estimation of weights among children in Kenya.
Section snippets
Study Design
To compare the validity of the Broselow tape and age-based formulas at estimating weights in Kenyan children, a prospective, cross-sectional study of sick children presenting to Moi Teaching and Referral Hospital in Eldoret, Kenya, was performed between May and June 2011. The study was approved by both the Indiana University Institutional Review Board and the Institutional Research and Ethics Committee at Moi Teaching and Referral Hospital.
Setting
Eldoret is a town of approximately 220,000 people,
Results
The study included 967 children ranging in age from 2 days to 14 years, with an adequate sample size in each Broselow category (Table 2). The interrater reliability analysis demonstrated good reliability, with a weighted κ coefficient of 0.98 (95% CI 0.96 to 1.00); the color code agreement was 96.5% (43/45), with 2 disagreements being by only 1 color zone.
Compared with age-based formulas, the Broselow tape was a better predictor of actual weights, with a mean percentage difference of −2.2% (95%
Limitations
This study has several potential limitations. Given the limited resources and personnel in the Sick Child Clinic, we were unable to track every patient for eligibility. In general, most patients were eligible and included in the study, making our results, we believe, generalizable to this patient population. Although we did not collect data on sex, previous studies have not shown any differences in the performance of the Broselow tape or age-based formulas between boys and girls. Also,
Discussion
To our knowledge, this study provides the first evidence that the Broselow tape and APLS formula provide valid estimates for children's weights in western Kenya. Overall, the Broselow tape outperformed age-based formulas. We believe these results will help clinicians in the resuscitation of critically ill children in other countries within sub-Saharan Africa.
As a single estimate of a child's weight, the Broselow tape provided the best agreement with actual weight. When used with age-based
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Cited by (34)
Estimating children's weight in a Rwandan emergency centre
2018, African Journal of Emergency MedicineCitation Excerpt :Wells et al. identified only one study from either East or Central Africa [8]. This study, from Kenya, did not present adequate data to assess the precision of age-based and Broselow Tape methods [12]. Even if it had, Rwanda has a much lower prevalence of underweight children one to five years old (11%) [13] than does Kenya (16.4%) [8].
The accuracy of the Broselow tape as a weight estimation tool and a drug-dosing guide – A systematic review and meta-analysis
2017, ResuscitationCitation Excerpt :This suggests that, even in the same study population, the Broselow tape was unable to estimate weight consistently in children of the same length. If habitus is not taken into account in the weight estimation, as has been recommended by previous authors, this is inevitable [2,5,16,17,32,44,55,58,73,81]. The pooled data showed an overall bias to underestimate weight, but with estimates as much as 30% below actual weight to 20% above actual weight.
A systematic review and meta-analysis of the accuracy of weight estimation systems used in paediatric emergency care in developing countries
2017, African Journal of Emergency MedicineWeight Estimation Methods in Children: A Systematic Review
2016, Annals of Emergency MedicineCitation Excerpt :We screened the abstracts of 131 studies and excluded 16 after screening and an additional 35 after full-text review (Figure). We thus included 80 studies on the topic of estimating weight in pediatric patients that met our inclusion criteria in this review.2,4,6-83 Studies were published from 1986 to 2016 and were conducted in 23 countries, although more were from the United States.
Development of a Japanese scale for assessment of paediatric normal weight
2016, ResuscitationUse of the broselow tape in a Mexican emergency department
2015, Journal of Emergency MedicineCitation Excerpt :Our findings are similar to more recent literature as well. To wit, in a study of 967 Kenyan children, House et al. found that the Broselow tape provided a valid estimate of weight, overestimating weight by a mean of only 2.2% and accurately predicting the correct color-zone 65.5% of the time, with the majority of misestimates of only one color zone (9). A study of South African children by Geduld et al. found that the Broselow tape estimated weight had a mean error of only 0.9% and was within 10% of the measured weight in 64.19% of subjects (10).
Please see page 2 for the Editor's Capsule Summary of this article.
Supervising editor: Kelly D. Young, MD, MS
Author contributions: DRH developed the idea for study in Kenya with the mentorship of DER. EN and RCV helped with development of protocol, given experience in Kenya. DRH, EN, RCV, and DER supervised the conduct of the study and managed data collection. DRH and DER analyzed the data. DRH wrote article, with EN, RCV, and DER providing significant contribution to editing and approval of final draft. DRH takes responsibility for the paper as a whole.
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article as per ICMJE conflict of interest guidelines (see www.icmje.org). The authors have stated that no such relationships exist.
Publication date: Available online August 31, 2012.
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