Height velocity screening: the real world.

To assess the value of the Middlesex-Height Velocity Screening Chart (based on the 50th velocity percentile +/- 1 SD) as a means of screening for abnormal growth in children, the heights of children at seven infant schools were measured on two separate occasions at least 12 months apart. A total of 229 children of mid-age (age of the child between the two measurements) ranging from 4.5 to 6.8 years were measured. Height velocity standard deviation score was calculated for each child by comparison with current Tanner-Whitehouse standards. The subjects were children who had a height recorded during the school entrant medical at least 12 months before the date of the second height measurement. The height velocity standard deviation score calculated for each child was related to the limits set by the Middlesex Screening Chart, and these criteria were used to determine whether or not the child had a 'normal' growth rate. It has been recommended that those falling outside these limits are referred for further assessment. It was found that 95 (41 percent) children fell outside the 'normal' range on the Middlesex chart (66 growing faster and 29 slower), which, if the guidelines were used uncritically, would result in the possible referral of 2500 5-6-year-olds in Sheffield alone. Taking into consideration the additional problems inherent in making two accurate height measurements from which a height velocity could be calculated, and the high number of referrals that would be generated as demonstrated by this study, height velocity screening for growth disorders using current methods is not feasible.