Smoothing reference centile curves: The lms method and penalized likelihood
Article first published online: 12 OCT 2006
Copyright © 1992 John Wiley & Sons, Ltd.
Statistics in Medicine
Volume 11, Issue 10, pages 1305–1319, 1992
How to Cite
Cole, T. J. and Green, P. J. (1992), Smoothing reference centile curves: The lms method and penalized likelihood. Statist. Med., 11: 1305–1319. doi: 10.1002/sim.4780111005
- Issue published online: 12 OCT 2006
- Article first published online: 12 OCT 2006
- Manuscript Revised: JAN 1992
- Manuscript Received: AUG 1991
Reference centile curves show the distribution of a measurement as it changes according to some covariate, often age. The LMS method summarizes the changing distribution by three curves representing the median, coefficient of variation and skewness, the latter expressed as a Box-Cox power. Using penalized likelihood the three curves can be fitted as cubic splines by non-linear regression, and the extent of smoothing required can be expressed in terms of smoothing parameters or equivalent degrees of freedom. The method is illustrated with data on triceps skinfold in Gambian girls and women, and body weight in U.S.A. girls.