Abstract
Background:
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.
Purpose:
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.
Methods:
The Avon Longitudinal Study of Parents and Children of the 90s (ALSPAC) is a longitudinal cohort study of children recruited antenatally, and followed prospectively. Assessment of sub ischial leg length was made on clinical measurements. There were up to 8 measurements per patient, 2311 girls with a final age at assessment of greater than 15 years and 123 males with a final age of assessment of greater than 16 years were assessed. We used the multiplier method to assess the predicted final leg length and compared this with the actual leg length
Result:
There was no difference between the multiplier in girls, in the contemporary cohort and the historical cohort. The average age of menarche in the contemporary group was 12.7. In boys the data is limited, due to later growth and it is not possible to draw comparisons from this group.
Conclusion:
This data provides good evidence that there has not been a significant change in growth trajectory in girls over the last 50 years.
Significance:
Implications on the confidence with which we can use the multiplier method in this population.
