Methods in Neuroepidemiology

Disability Evolution in Multiple Sclerosis: How to Deal with Missing Transition Times in the Markov Model?
V. Petiot^a, C. Quantin^a, G. Le Teuff^a, M. Chavance^c, C. Binquet^a, M. Abrahamowicz^{d, e}, T. Moreau<sup>b

a</sup>Service de Biostatistique et d'Informatique Médicale and
^bService de Neurology, CHRU Dijon, Dijon, and
^cInserm, U472, Paris, France;
^dDepartment of Epidemiology and Biostatistics, McGill University and
^eDivision of Clinical Epidemiology, McGill University Health Centre, Montreal, Canada

Address of Corresponding Author

Neuroepidemiology 2007;28:56-64 (DOI: 10.1159/000098518)

  Key Words

• Multiple sclerosis
• Markov model
• Missing data
• Multiple imputation

  Abstract

Markov modeling of disability progression in multiple sclerosis requires knowledge of all times of transitions from a given level of disability to the next level, but such data are often missing. We address methodological challenges due to partly missing transition times. To estimate the effects of prognostic factors on the risk of transitions between three consecutive disability levels, two methods were used to deal with missing data. Listwise deletion limited the analysis to subjects with complete data. Multiple imputation of missing data revealed that data were missing at random (MAR mechanism) and imputed the missing transition times from the Weibull model. The results were then compared with the full data set with the actual times established through chart review. Multiple imputation estimates were systematically closer to those from the full data set than the listwise deletion estimates.

Copyright © 2007 S. Karger AG, Basel

  Author Contacts

Catherine Quantin, MD, PhD
Service de Biostatistique et Informatique Médicale, CHRU Dijon
1, boulevard Jeanne d'Arc, BP 77908
FR-21079 Dijon Cedex (France)
Tel. +33 3 80 29 36 29, Fax +33 3 80 29 39 73, E-Mail catherine.quantin@chu-dijon.fr

  Article Information

Published online: January 11, 2007
Number of Print Pages : 9
Number of Figures : 2, Number of Tables : 3, Number of References : 41