ESTIMATION OF ANNUAL HEIGHT VELOCITY BASED ON SHORT-VERSUS LONG-TERM MEASUREMENTS

We assessed the relationships between annual height velocity, calculat ed from two measurements taken at intervals of 6, 12 and 24 months, in 69 healthy prepubertal children (34 male, 3 5 female) aged 6.5 years (range 6.25-6.75 yrs) who were followed for 2.5 years and measured bia nnually. Initial height values for age were within normal ranges excep t for one child with a height SDS of - 2.0. Mean annual velocities als o conformed to British norms. Significant differences were observed be tween consecutive six-monthly velocities and these values failed to pr edict annual velocities calculated from measurements taken at 12- or 2 4-month intervals. Seasonal effects were thought to have some impact o n the six-monthly velocity differences. Height velocity, based on meas urements taken at intervals of 12 months, was essentially similar to t wo-year velocity values. The results indicate that in estimating annua l height velocity, six-month intervals between measurements may be mis leading while 12-monthly measurements are as reliable as height veloci ty values based on measurements taken at two-year intervals.