The study by Jackson et al1 attempts to fill a gap in our knowledge in a very important area. Paediatricians in the United Kingdom have traditionally not included a blood pressure measurement as part of routine clinical assessment, as hypertension is not generally considered to be a common paediatric problem. Those who did check blood pressure had to rely on normal values derived from European and North American studies. The provision of blood pressures centiles for Great Britain is therefore a big step in the right direction and this is warmly welcomed. The data have been pooled from large representative samples and the methodology appears to be robust. The authors have chosen the well tested traditional nine-centile system, which all British health professionals are familiar with. However, a number of issues should be raised.

Firstly, the observed blood pressure appears to be remarkably high in a significant proportion of the paediatric population. This is most obvious in the …