Paley et al has developed the multiplier method for predicting leg length. It is a tool that is used clinically to predict leg length discrepancy. The method is also a way of comparing different populations, to identify differences in growth trajectory. This has been done by identifying the differing multipliers for girls and boys. However it has not been used to identify trends in populations separated by time. Tanner showed that in the first half of the twentieth century girls went from an average age of menarche of 15 in 1900, to 13 in 1970, how this has affected growth trajectory over the last 50 years has not been studied. The multiplier method is based on data collected in the 1950's by Anderson and Green, we aim to assess whether there has been a change in growth trajectory between this historical cohort and a contemporary European based cohort.Background:
Purpose:
Paley et al has developed a multiplier method for calculating both leg length and total height. In the development of this algorithm, they evaluated the effect of factors including bone age and sex. They established that sex had a significant impact, but adjusting for bone age did not improve accuracy. Bone age and menarche have been shown to improve other height prediction models. We used a large prospective cohort to evaluate if the multiplier is independent of physiological age using menarche as a proxy.Introduction:
Purpose:
Paley et al developed a mathematical model to predict height, using age, sex and current height. His predictions were based on growth charts from epidemiological databases, and then validated using 52 children. We looked at a recent large, local database, to assess whether the height multiplier is a reliable tool that can be used in clinical practice. The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a population based cohort study of 14, 000 contemporary British families. 5363 children had final height measured with an average of 10.5 additional height measurements. The height multiplier equation was defined as height at specific age divided by height at skeletal maturity. No significant difference was observed between the mean results from Paley et al and the ALSPAC data. There was a significant range of results in the ALSPAC data, with a standard deviation of the multiplier of 0.08 for ages 7–15. This large population study shows no significant difference between the historical databases Paley used and the more current European databases. The large range of results shown by the ALSPAC cast doubt on the clinical usefulness of individual results.
