pchreg: Piecewise Constant Proportional Hazards Regression

In eha: Event History Analysis

Piecewise Constant Proportional Hazards Regression

Description

Proportional hazards model with piecewise constant baseline hazard(s). Allows for stratification and left truncated and right censored data.

Usage

pchreg(
  formula = formula(data),
  data = parent.frame(),
  na.action = getOption("na.action"),
  cuts = NULL,
  init,
  control = list(eps = 1e-08, maxiter = 20, trace = FALSE),
  singular.ok = TRUE,
  model = FALSE,
  x = FALSE,
  y = TRUE
)

Arguments

formula	a formula object, with the response on the left of a ~ operator, and the terms on the right. The response must be a survival object as returned by the Surv function.
data	a data.frame in which to interpret the variables named in the formula.
na.action	a missing-data filter function, applied to the model.frame, after any subset argument has been used. Default is options()$na.action.
cuts	Specifies the points in time where the hazard function jumps. If omitted, an exponential model is fitted.
init	vector of initial values of the iteration. Default initial value is zero for all variables.
control	a list with components eps (convergence criterion), maxiter (maximum number of iterations), and silent (logical, controlling amount of output). You can change any component without mention the other(s).
singular.ok	Not used.
model	Not used.
x	Return the design matrix in the model object?
y	Return the response in the model object?

Value

A list of class "pchreg" with components

coefficients	Fitted parameter estimates.
cuts	Cut points (NULL if no cut points).
hazards	The estimated constant levels.
var	Covariance matrix of the estimates.
loglik	Vector of length two; first component is the value at the initial parameter values, the second component is the maximized value.
score	The score test statistic (at the initial value).
linear.predictors	The estimated linear predictors.
means	Means of the columns of the design matrix, except those columns corresponding to a factor level. Otherwise all zero.
w.means	Weighted (against exposure time) means of covariates; weighted relative frequencies of levels of factors.
n	Number of spells in indata (possibly after removal of cases with NA's).
n.events	Number of events in data.
terms	Used by extractor functions.
assign	Used by extractor functions.
wald.test	The Wald test statistic (at the initial value).
y	The Surv vector.
isF	Logical vector indicating the covariates that are factors.
covars	The covariates.
ttr	Total Time at Risk.
levels	List of levels of factors.
formula	The calling formula.
call	The call.
method	The method.
convergence	Did the optimization converge?
fail	Did the optimization fail? (Is NULL if not).

Author(s)

Göran Broström

See Also

phreg, coxreg, link{aftreg}.

Examples

## Not run: 
dat <- age.window(oldmort, c(60, 80))
fit <- pchreg(Surv(enter, exit, event) ~ ses.50 + sex, 
data = dat, cuts = seq(60, 80, by = 4))
summary(fit)

fit.cr <- coxreg(Surv(enter, exit, event) ~ ses.50 + sex, data = dat)
check.dist(fit.cr, fit, main = "Cumulative hazards")

## End(Not run)

eha documentation built on Oct. 7, 2024, 1:17 a.m.