Novel illness-death model with application to the UK-Biobank survival data
Speaker: Malka Gorfine, Dept. of Statistics, Tel Aviv University, Israel
The UK Biobank is a large-scale health resource comprising genetic, environmental
and medical information on approximately 500,000 volunteer participants in the UK,
recruited at ages 40-69 during the years 2006-2010. The project monitors the health
and well-being of its participants. This work demonstrates how these data can be
used to estimate in a semi-parametric fashion the effects of genetic and environmental
risk factors on the hazard functions of various diseases, such as colorectal cancer.
An illness-death model is adopted, which inherently is a semi-competing risks model,
since death can censor the disease, but not vice versa. Using a shared-frailty approach
to account for the dependence between time to disease diagnosis and time to death,
we provide a new illness-death model that assumes Cox models for the marginal
hazard functions. The recruitment procedure used in this study introduces delayed
entry to the data. An additional challenge arising from the recruitment procedure is
that information coming from both prevalent and incident cases must be aggregated.
Lastly, we do not observe any deaths prior to the minimal recruitment age, 40. In
this talk I present an estimation procedure for our new illness-death model that
overcomes all the above challenges.