Paediatric growth charts: How do we use them and can we use them better?
- Conflict of interest: None declared.
Correspondence: Dr Alan Dugdale, Department of Paediatrics and Child Health, University of Queensland, Herston, QLD Q4006, Australia. Fax: 61 (0)7 3041 0229; email: A.Dugdale@uq.edu.au
The paper by Ramsden and Day confirms previous reports that child growth is often neglected in acute paediatric medicine. As an academic who has designed and used growth charts, I regret this failure; as a practising paediatrician, I understand the difficulties faced in acute medicine. When a sick child comes to a clinic, we first collect data for immediate diagnosis and management of the acute condition. Other data have a lower priority. The Ramsden paper asks whether time and effort spent collecting growth data are efficient uses of valuable staff and time.
To justify growth measurements in a clinic for acutely ill children, we must ask and answer the following questions.
Is It Feasible to Take These Measurements in an Area Handling Acute, and Sometimes Urgent, Even Life-Threatening, Medical Conditions?
Measuring weight is simple even for a sick child in a non-specialised unit. Mother stands on scales, holding the child and then without the child; the difference is the weight of the child with acceptable accuracy.
To measure height accurately, we need a height scale, usually attached to a wall; the child must stand erect long enough for the measurement. Sick children cannot do this. It could be said that if a child is fit enough to do this, he or she should not be there. For infants, we need a measuring board with sliding footpiece. Infants and their mothers dislike the pressures put on the infant to get an accurate measure, and such measuring may be contraindicated in an acutely ill infant.
We need only a tape measure to get the head circumference, but accurate measurement needs practice.
Can We Use the Data to Help This Child in the Acute Illness or Later Clinical Situations?
Weight is used to calculate drug doses and fluid requirements so is needed for acute care. Height and head circumference are seldom needed for the acute problem. The measurements have value only when plotted on a percentile chart; this takes more time from the acute management. We should plot percentiles on the latest World Health Organization growth charts, which are recommended worldwide, but are seldom used in Australia. A single measurement of height and head circumference, even when plotted on a chart, would have little value unless it was grossly abnormal. Repeated measurements plotted on a growth chart are more likely to show up deviations in growth. In an acute hospital setting, where single visits are common and regular visits rare, it would be unusual to have growth charts with sufficient points to make a previously unconsidered diagnosis. If a child has a regular general practitioner who plots growth at each visit, there would be more chance of detecting abnormalities early.
Is Existing Data Being Fully Used?
Before asking for more data, we should check that the data already collected are fully used. Ninety-eight children (95% of the sample) had weight measured and recorded, but only 7% had the data plotted on a growth chart. Presumably the staff needed these data for immediate clinical care but did consider other uses. Percentile weight-for-age is the single most useful indicator of overnutrition or undernutrition; until this information is fully used clinically and epidemiologically, we cannot expect busy staff to undertake other more difficult measurements.
Is it Feasible and Useful to Do These Measurements in Specialist and GP Clinics?
My answers here are simple – for both short-term and long-term clinical supervision, the answer is emphatically yes. As a source of public health data, the answer is definitely no.