Evaluation of the natural history of disease by combining incident and prevalent cohorts: application to the Nun Study

Lifetime Data Anal. 2023 Oct;29(4):752-768. doi: 10.1007/s10985-023-09602-x. Epub 2023 May 20.

Abstract

The Nun study is a well-known longitudinal epidemiology study of aging and dementia that recruited elderly nuns who were not yet diagnosed with dementia (i.e., incident cohort) and who had dementia prior to entry (i.e., prevalent cohort). In such a natural history of disease study, multistate modeling of the combined data from both incident and prevalent cohorts is desirable to improve the efficiency of inference. While important, the multistate modeling approaches for the combined data have been scarcely used in practice because prevalent samples do not provide the exact date of disease onset and do not represent the target population due to left-truncation. In this paper, we demonstrate how to adequately combine both incident and prevalent cohorts to examine risk factors for every possible transition in studying the natural history of dementia. We adapt a four-state nonhomogeneous Markov model to characterize all transitions between different clinical stages, including plausible reversible transitions. The estimating procedure using the combined data leads to efficiency gains for every transition compared to those from the incident cohort data only.

Keywords: Combined cohort data; Incident cohort; Interval censoring; Left truncation; Multistate model; Prevalent cohort.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Dementia* / epidemiology
  • Humans
  • Longitudinal Studies
  • Nuns*
  • Risk Factors