Implements weighted cumulative exposure Cox proportional hazards
models for latency analysis with repeatedly measured, time-varying
exposures. Instead of entering every lagged exposure as a separate and
highly correlated covariate, the lag-specific log hazard ratios are
constrained to follow a smooth function of the time since exposure,
parameterized by natural cubic splines or polynomials, so that the
susceptible window of an exposure can be identified from the estimated
lag-risk curve. Functions are provided to fit models with a
prespecified number of knots or polynomial degree, to select the number
of knots by a grid search or the spline terms by a stepwise search using
the Akaike or Bayesian information criterion, and to extract
lag-specific log hazard ratios with their variances. For the
data-driven model selection procedures, inference is based on a cluster
bootstrap that resamples subjects, which can be run sequentially or in
parallel. The methods are described in Guo, Qian, Wang, Wang, Rosner and
Wang (2026) "Taking Into Account the Susceptible Window for Exposures in
Cox Proportional Hazards Model: A Way Using Splines to Model the Lag-Risk
Relationship"
Install the package using the code
library(devtools)
install_github("fyGuo/LatencyA")