A copula model for marked point processes

Liqun Diao1, Richard J Cook, Ker-Ai Lee

  • 1Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON, N2L 3G1, Canada, l2diao@uwaterloo.ca.

Insights

This study introduces a new statistical model for analyzing recurring disease events and their associated continuous variables, like severity or treatment response. The model uses copula functions to link event timing and event characteristics, improving data analysis efficiency.

Area of Science:

  • Biostatistics
  • Epidemiology
  • Medical Statistics

Background:

  • Chronic diseases often involve recurring events with associated continuous variables (e.g., severity, cost, treatment response).
  • Analyzing both event occurrences and their associated marks simultaneously presents statistical challenges.

Purpose of the Study:

  • To develop a novel statistical model for marked point processes that accounts for dependence between continuous marks and event times.
  • To evaluate the efficiency of joint versus separate analyses of event times and marks.

Main Methods:

  • A copula-based model was developed to link the event process (point process) and the continuous mark distribution.
  • The model allows for flexible specification of both event intensity functions and multivariate mark models.
  • Simulations were conducted under random censoring to assess the relative efficiency of joint analysis.

Main Results:

  • The proposed copula model effectively incorporates dependence between event times and continuous marks.
  • Joint analysis demonstrated improved efficiency compared to separate analyses in simulations.
  • The model was successfully applied to transfusion medicine trial data.

Conclusions:

  • The novel copula-based marked point process model provides a flexible and efficient framework for analyzing complex event data in chronic diseases.
  • This approach enhances the understanding of disease progression and treatment effects by jointly modeling event timing and characteristics.
  • The findings have implications for clinical trial analysis and understanding disease dynamics.

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