Computational and Mathematical Methods in Medicine
Volume 10 (2009), Issue 2, Pages 155-164
Original Article

How to Obtain Long Term Projections for Smoking Behaviour: A Case Study in the Dutch Population

1Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, University of Leiden, Leiden, The Netherlands
2Expertise Centre for Methodology and Information Services, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
3STIVORO for a Smoke Free Future, Expertise Centre on Tobacco Control, Den Haag, The Netherlands

Copyright © 2009 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A state-transition model is presented to project the prevalence rates of never, current and former smokers within the Dutch population. Changes are determined by the transition rates among these three classes: start rates, quit rates and relapse rates. Both the initial prevalence rates and transition rates are calculated from cross-sectional data using a restricted quadratic multinomial regression spline and a restricted quadratic logistic regression spline, respectively. Through a Monte Carlo experiment an uncertainty analysis was performed to assess the level of reliability of the results, while a sensitivity analysis was carried out in order to detect the input variables that mostly contribute to the output variability. The results obtained through this model show a considerable but rather slow decrease of smokers up to year 2050.