visit_sum: Create Visit Sum Covariate

In gfoRmula: Parametric G-Formula

Create Visit Sum Covariate

Description

This internal function assists in the implementation of a visit process by creating a covariate, ts_visit, that counts the number of visits in the past max_visits time points. If this number is greater than 0, then the individual has not missed more than the maximum number of visits.

Usage

visit_sum(pool, histvars, time_name, t, id_name, max_visits)

Arguments

pool	Data table containing all information prior to time t (t noninclusive).
histvars	Vector of character strings specifying the names of the variables for which lagged cumulative averages are to be created.
time_name	Character string specifying the name of the time variable in pool.
t	Integer specifying the current time index.
id_name	Character string specifying the name of the ID variable in pool.
max_visits	A vector of one or more values denoting the maximum number of times a binary covariate representing a visit process may be missed before the individual is censored from the data (in the observed data) or a visit is forced (in the simulated data). Multiple values exist in the vector when the modeling of more than covariate is attached to a visit process.

Value

No value is returned. The data table pool is modified in place.

gfoRmula documentation built on May 31, 2023, 9:46 p.m.