According to the study narrative and Figure 1 in the Flannigan et al. (2014) study, does the APLS UK formulae under- or overestimate the weight of children younger than 1 year of age?
According to the narrative and Figure 1 in the Flannigan et al. (2014) study, the APLS UK overestimates the children’s weight on the value from 10 to 25.4%. Authors used an improved formula, with α=0.05 which requires the calculation of the age in months and adding 4 inches.
Using the values a = 3.161 and b = 0.502 with the novel formula in Figure 1, what is the predicted weight in kilograms (kg) for a child at 9 months of age?
To predict the child’s weight, the following should calculate:
y = 0.502 * 9 + 3.161 = 7.679.
Therefore, the predictable weight of 9 months old child is 7.679 kg.
Using the values a = 3.161 and b = 0.502 with the novel formula in Figure 1, what is the predicted weight in kilograms for a child at 2 months of age?
To predict the child’s weight, the following should calculate:
y = 0.502 * 2 + 3.161 = 4.165.
Therefore, the predictable weight of 9 months old child is 4.165 kg.
In Figure 2, the formula for calculating y (weight in kg) is Weight in kg = (0.176 × age in months) + 7.241. What is the y intercept and the slope in this formula?
Y intercept is a weight in kilograms. It is 7.241.
Y slope is 0.176 x age of a child in months.
Using the values a = 7.241 and b = 0.176 with the novel formula in Figure 2, what is the predicted weight in kilograms for a child 3 years of age?
First, it is important to calculate the age of a child in months:
3 years = 3*12 = 36 months
y = 0.176*36+7.241 = 13.577
Therefore, the predictable age of 3 years old child is 13.577 kg.
Using the values a = 7.241 and b = 0.176 with the novel formula in Figure 2, what is the predicted weight in kilograms for a child 5 years of age?
First, it is important to calculate the age of a child in months:
5 years = *12 = 60 months
y = 0.176*60+7.241 = 17.801
Therefore, the predictable age of 3 years old child is 17.801 kg.
In Figure 3, some of the actual mean weights represented by the blue line with squares are above the dotted straight line for the novel formula, but others are below the straight line. Is this an expected finding?
Yes, it is the expected finding. Due to the fact that a large standard deviation is always present in children’s group, the mean weight itself is not a reliable value. It is important to prevent errors in children’s’ weight prediction because such errors lead to other mistakes, for example, to errors in the medications’ concentration prescription.
In Figure 3, the novel formula is (Weight in kilograms = (0.331 × Age in months) – 6.868. What is the predicted weight in kilograms for a child 10 years old?
First, it is important to calculate the age of a child in months:
10 years = 10*12 = 120 months.
According to the formula in Figure 3, the calculation will be the following:
y = 0.331*120-6.868 = 32.852
Therefore, the predictable weight of 10 years old child will be 32.852 kg.
Was the sample size of this study adequate for conducting simple linear regression?
The sample size was appropriate to represent simple linear regression because more than 10,000 children were involved. This sample size could be considered as large enough.
What are potential clinical advantage and one potential clinical problem with using the three novel formulas presented in Figures 1, 2, and 3 in a PICU setting?
PICU setting is a unit for children that require emergency help. Therefore, it is important to provide them with the appropriate dose of medication. The dose of drugs is calculated based on child’s weight. Frequently, health care providers do not have time to measure the weight. Presented formulas do not provide a precise result of weight but provide a range of values. It could be cited as a disadvantage. However, in case of emergency it is possible to use this range which is better than nothing. Thus, these formulas provide an opportunity for needed drug usage until a child would be stabilized and one’s weight could be measured.
Reference List
Flannigan, C., Bourke, T. W., Sproule, A., Stevenson, M., & Terris, M. (2014). Are APLS formulae for estimating weight appropriate for use in children admitted to PICU? Resuscitation, 85(7), 927–931.