Redesigning children’s growth charts
Submitting Institution
University College LondonUnit of Assessment
Public Health, Health Services and Primary CareSummary Impact Type
HealthResearch Subject Area(s)
Medical and Health Sciences: Public Health and Health Services
Summary of the impact
Research at the UCL Institute of Child Health underpinned the update in
2009 of children's growth charts, which allow for more accurate
determination of a child's growth pattern and provide better tools for
assessing possible weight problems in children. The new charts are now in
universal use in the UK for children from birth to 18 years of age,
including preterm babies. Having been quickly adopted, they now account
for 90% of all growth chart sales. Modified versions of the charts are in
use in Ireland and New Zealand. In the UK they are provided to all new
parents as part of the Personal Child Health Record (PCHR) — known as the
"red book". They are used in general practice, community paediatrics,
general paediatrics and paediatric endocrinology. The most recent charts
are for use in children with growth or nutritional problems.
Underpinning research
Until 2009, growth charts used in the UK were based on the British 1990
reference. Following a recommendation by the English Department of Health
(DH) Scientific Advisory Committee on Nutrition (SACN), they were replaced
by new charts based on the World Health Organization (WHO) 2006 growth
standard. These new UK-WHO charts were designed by a Growth Chart Expert
Group commissioned through the Royal College of Paediatrics and Child
Health (RCPCH), which included Professors Tim Cole and Gary Butler, and Dr
Helen Bedford (all UCL Institute of Child Health). The Expert Group was
chaired by Professor Charlotte Wright (Glasgow University), who is using
her chart development work as a separate REF case study.
The charts for 0 to 4 year olds, launched in May 2009, used WHO growth
standard data from two weeks to four years, and reanalysed birth data from
the British 1990 reference [1]. Further charts extending the age
range to 18 years were launched in May 2012, based on the same British
1990 reference as before but to an improved design. In addition more
specialised "close monitoring" charts were developed for neonates and
infants (NICM) and childhood and puberty (CPCM). They incorporate a series
of innovative plotting aids devised by Professor Cole, who was thus
responsible for the following features:
- Centiles for birth weight, length and head circumference for 23-42
weeks of gestation constructed using Cole's LMS method [2, 3].
For this Cole used the LMS method to update pre-existing birth centiles
to augment the WHO growth standard (which lacked preterm data).
- A Body Mass Index (BMI) look-up that converts height centile and
weight centile to a BMI centile [4]. Here Cole used the strong
relation between centiles of weight, height and BMI to predict BMI
centile. As a result, knowing centiles of weight and height, BMI centile
can be predicted to reasonable accuracy without having to calculate or
plot BMI on a centile chart.
- An adult height predictor, a nomogram to convert the child's current
height centile (at any age) to a predicted adult height, adjusted for
regression to the mean [5]. This was joint work with Wright, and
a simplified version was included with the growth chart. As well as
being popular with parents and children, the height prediction is used
in conjunction with the parent height comparator (see below) to detect
growth disorders.
- A parent height comparator, a nomogram to compare the child's height
centile to the mid-parent height centile adjusted for regression to the
mean. Again, in joint work with Wright, it provides a graphical method
to calculate an improved version of mid-parent height that, with the
height predictor (above), detects disordered growth where the two height
estimates are discordant.
Centiles for height and weight for three phases of puberty were
constructed using the LMS method. This was joint work with Butler and
Wright, where the five Tanner pubertal stages were rationalised into three
pubertal phases, and reference centiles for height and weight were
constructed for children in each of the three phases separately. Elements
of these centiles were incorporated in the CPCM charts to monitor growth
in delayed puberty.
References to the research
[2] Cole TJ, Williams AF, Wright CM, RCPCH Growth Chart Expert Group.
Revised birth centiles for weight, length and head circumference in the
UK-WHO growth charts. Ann Hum Biol 2011;38:7-11. http://dx.doi.org/10.3109/03014460.2011.544139
[3] Cole TJ, Wright CM, Williams AF, RCPCH Growth Chart Expert Group.
Designing the new UK-WHO growth charts to enhance assessment of growth
around birth. Arch Dis Child 2011;
http://dx.doi.org/10.1136/adc.2010.205864
Peer-reviewed funding
Cole has held four successive MRC programme grants:
- Mathematical methods in the assessment of human growth
- Oct 1998 - Sep 2003, £381,000
- Oct 2003 - Sep 2008, £380,000
- Oct 2008 - Nov 2011, £355,000
- The SITAR method of growth curve analysis for growth assessment in
translational medicine and life course epidemiology
- Apr 2012 - Mar 2015, £79,000.
Details of the impact
Since their launch in the UK in 2009, the UK-WHO growth charts developed
by Cole and others are now used universally. They were introduced in
England in May 2009, in Wales and Scotland in January 2010 and in Northern
Ireland in October 2010 [a]. The charts are available in two
formats: A5 charts that are included in the personal child health record
(PCHR) known as the "red book", and A4 professional charts (0-4 years,
2-18 years, NICM). All new mothers receive a copy of the PCHR, [b]
so that in 2012, for example, the PCHR was distributed to all parents of
the 813,000 infants born in the four countries that year. The charts and
their interpretation were also discussed in the government's Birth to
Five book, produced by the Department of Health in 2009 and
distributed free to all new parents in England until 2011; in Wales a
bilingual edition is issued [c].
The A4 professional charts are used in primary, secondary and tertiary
care, and for the year to April 2013 the numbers sold by the publishers,
Harlow Printing Limited, for each chart were as follows:
- 0-4 years - 400,000 copies
- 2-18 years - 287,000 copies
- NICM - 95,000 copies [d]
These numbers are impressive, not only in terms of their size, but also
because they show how rapidly the UK-WHO charts have superseded the
previous British 1990 charts (amounting to 90% of total growth chart
sales).
As they enable practitioners to recognise the range of normal
development, the UK-WHO charts are uniquely well designed to achieve UK
government policy aims in relation to child health, namely with regard to
early recognition of growth disorders and risk factors for obesity, as
defined in the Healthy Child Programme [b, e]. In June 2013, the
CPCM chart was released. This is a modification of the main school age
chart for use in children with growth or nutritional problems. It extends
to age 20 years and features a body mass index (BMI) chart; low and high
lines to monitor unusually short, thin or overweight children; puberty
phase specific thresholds to assess small children with late onset puberty
and tall children with early onset puberty [f].
The UK work has also had an impact internationally. For example, the 0-4
years and NICM charts have been adapted for use in New Zealand [g],
where they have been used since mid-2010. From January 2013, they have
also been in use in Ireland [h], where all newborn infants are
assessed using them. As an indication of reach, 72,000 babies were born in
Ireland in 2012 [i].
The guiding principles in the chart design were that the charts should be
evidence-based, useful and easy to use — and hence more likely to be
effective. Parents often claim to understand growth charts, yet they show
only limited comprehension when tested [j]. Therefore the charts
were developed with better layout than before, and with instructions for
the PCHR and A4 charts targeted at their respective audiences, parents and
professionals [k].
The new and improved elements on the charts also benefit both parents and
professionals. These include a reduced emphasis on the 50th
centile, as sometimes parents expect all `normal' children to grow along
the 50th centile line. On the new charts however, there are more centile
labels and the curve labels sit on the 50th centile to assist orientation
when plotting and interpreting [l]. A `dip' in weight between 2-4
weeks is no longer seen, as the charts have more information on weight
gain in the first few weeks, and they allow for the average tendency for
infants to show a slower net weight gain up to age 2 weeks [l].
The new adult height predictor tells parents how tall their child will
be, a matter of endless interest. It also allows professionals to compare
the prediction with the parents' heights, and hence detect a possible
growth disorder. For this a graphical parent height comparator is
provided, which improves on the British 1990 calculator by avoiding the
need for any calculations.
Child obesity is a considerable public health concern, and these charts
provide better tools for assessing possible weight problems in children.
In the past, BMI in children has been relatively little used as a
screening tool, due to the need for calculation and a separate BMI chart.
The new charts include a BMI look-up, which provides the BMI centile from
the height and weight centiles, avoiding both BMI calculation and a BMI
chart. This makes it easy to plot the child's BMI centile over time, and
it is likely to considerably increase parental and professional awareness
of a child's overweight, which parents are poor at recognising [m].
Sources to corroborate the impact
[a] Information accompanying the introduction of the new growth charts in
England in May 2009:
http://www.smahcp.co.uk/professional-know-how/growth-charts/new-growth-charts/information-771.aspx?catid=22
Introduction in Scotland: http://www.scotland.gov.uk/Resource/Doc/337318/0110676.pdf
See p6.
[b] Healthy Child Programme — Pregnancy and the first five years. English
Department of Health.
http://webarchive.nationalarchives.gov.uk/20130107105354/http://www.dh.gov.uk/prod_consu
m_dh/groups/dh_digitalassets/@dh/@en/@ps/documents/digitalasset/dh_118525.pdf
See p 8 for policy aims; p 58 for details of the PCHR.
[c] Birth to Five book, Chapter 4, p. 66, http://www.publichealth.hscni.net/publications/birth-five;
Continued use in Wales
http://wales.gov.uk/topics/health/improvement/index/earlyyears/?lang=en
[d] Personal communication from Harlow Printing Limited (copy available
on request)
[e] Healthy Child Programme — From 5-19 years old. English Department of
Health.
http://webarchive.nationalarchives.gov.uk/+/www.dh.gov.uk/en/publicationsandstatistics/publications/publicationspolicyandguidance/dh_107566
[f] School age charts and resources, RCPCH, http://www.rcpch.ac.uk/child-health/research-projects/uk-who-growth-charts/uk-growth-chart-resources-2-18-years/school-age
[g] Well Child growth charts. Ministry of Health, New Zealand. http://www.health.govt.nz/our-work/life-stages/child-health/well-child-tamariki-ora-services/growth-charts
[h] UK-WHO-Ireland growth charts. Health Services Executive, Ireland.
http://www.hse.ie/growthmonitoring/
[i] Ireland Perinatal Statistics Report 2012:
http://www.esri.ie/news_events/latest_press_releases/perinatal-statistics-repo-1/index.xml
[j] Do Parents Understand Growth Charts? A National, Internet-Based
Survey; EP Ben-Joseph, SA Dowshen, N Izenberg, Pediatrics 124(4) Oct 2009;
pp. 1100 -1109
http://doi.org/10.1542/peds.2008-0797
[k] Sachs M, Sharp L, Bedford H, et al. 'Now I understand': consulting
parents on chart design and parental information for the UK-WHO child
growth charts. Child Care Health Dev 2012;38:435-40. http://doi.org/10.1111/j.1365-2214.2011.01256.x
[l] The UK-WHO Growth Charts: What is the difference?
http://www.rcpch.ac.uk/sites/default/files/asset_library/Research/Growth%20Charts/Education
%20Materials%2001092010/FS2_What%20is%20the%20differenceN.pdf
[m] Maternal and Child Awareness and Expectations of Child Overweight; A
Brødsgaard, L Wagner, B Peitersen, I Poulsen, T Sørensen; Obesity Facts
2011;4:297-304;
http://doi.org/10.1159/000331012