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Measuring and Plotting

Plotting using the new UK-WHO Growth Charts

Presentation D

Adapted from training materials of the Royal College of Paediatrics and Child Health [RCPCH]

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Measuring and Plotting

Plotting the Chart• Record measurement and date in ink, plot in pencil

• Use a dot; do not join up

• Age errors are commonest source of plotting mistakes use a calendar or date wheel to calculate age– Age in weeks for first 6-12 months– Calendar months thereafter

• Count forward from the date of birth to current month using day birth e.g. if date of birth is 26/6/09, then age 13 months is on 23/7/10

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Measuring and Plotting

What do the Centiles Show?• Optimum range of weight and heights

• Describes the percentage expected to be below that line– 50% below 50th

– 91% below 91st

– 1 in 250 below 0.4th

• Half of all children should be between 25-75th centile

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Measuring and Plotting

Centile Terminology

If the point is exactly on the centile line, or within ¼ of a space of the centile line, the child is described as being ‘on the X centile’ (see A) e.g. on the 91st centile.

If not they should be described as being ‘between centile X and Y’ (see B) e.g. between the 75th -91st centile.

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Measuring and Plotting

Centile Spaces

A ‘centile space’ is the distance between two centile lines (e.g. C).

Two measurements can be described as a centile space apart if they are both midway between centiles (e.g. D).

Falls or rises should be expressed as multiples of centile spaces (e.g. a fall through 2 ½ centile spaces).

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Measuring and Plotting

Summary: Plotting and Centiles

• Record measurement and date in ink

• Plot one single dot in pencil-[no ‘fried eggs’, or joining up]

• Age errors are commonest source of plotting mistakes

• Centiles describes the percentage expected to be below that line

• A child is– on a centile if within ¼ space of line– between the two centiles if not on (or within ¼ space of) a centile

• A centile space is the distance between two centile lines

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Measuring and PlottingMeasuring and plotting: Activity 2 Answers

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Measuring and PlottingMeasuring and plotting: Activity 2 Answers

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Measuring and PlottingMeasuring and plotting: Activity 2 Answers