Plotting using the new UK-WHO Growth Charts Presentation D

1. Plotting using the new UK-WHO Growth ChartsPresentation D Adapted from training materials of the Royal College of Paediatrics and Child Health [RCPCH]

2. 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

3. 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

4. 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.

5. 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).

6. 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