### Abstract

- Top of page
- Abstract
- 1. Introduction
- 2. MRC CFAS
- 3. Methods
- 4. Data analysis
- 5. Discussion
- Appendix A
- Acknowledgements
- References

Semi-competing risks data occur frequently in medical research when interest is in simultaneous modelling of two or more processes, one of which may censor the others. We consider the analysis of semi-competing risks data in the presence of interval-censoring and informative loss-to-followup. The work is motivated by a data set from the MRC UK Cognitive Function and Ageing Study, which we use to model two processes, cognitive impairment and death. Analysis is carried out using a multi-state model, which is an extension of that used by Siannis *et al*. (*Statist. Med.* 2007; **26**:426–442) to model semi-competing risks data with exact transition times, to data which is interval-censored. Model parameters are estimated using maximum likelihood. The role of a sensitivity parameter *k*, which influences the nature of informative censoring, is explored. Copyright © 2010 John Wiley & Sons, Ltd.