Handling the limit of detection by extrapolation


N. T. Longford, SNTL and Departament d'Economia i Empresa, Universitat Pompeu Fabra, c/ Ramon Trias Fargas 25–27, 08005 Barcelona, Spain.

E-mail: NTL@sntl.co.uk


A general method of estimation with a variable observed subject to a limit of detection is introduced. It is based on extrapolation of the estimates obtained by increasing the limit of detection. Theoretical arguments support the method in some special cases, and it is explored by simulations. Several examples are presented and adaptations for other kinds of censoring explored. Copyright © 2012 John Wiley & Sons, Ltd.