surv_pred_info {shinyCox}

Obtains information for standard errors of predictions

Description

Computes necessary information to calculate standard errors and confidence intervals in shiny app. This is adapted from parts of survfit.coxph(). This function is meant to be used in conjunction with predict_se().

Usage

surv_pred_info(model, ctype, individual = FALSE, id, se.fit = TRUE, stype = 2)

Arguments

model

a coxph object

ctype

whether the cumulative hazard computation should have a correction for ties, 1=no, 2=yes.

individual

deprecated argument, replaced by id

id

optional variable name of subject identifiers. Not supported in app

se.fit

a logical value indicating whether standard errors should be computed. Default is TRUE for standard models, FALSE for multi-state (code not yet present for that case.)

stype

computation of the survival curve, 1=direct, 2=exponential of the cumulative hazard. Default is 2.

Value

A list of information needed for computing predicted standard errors.

Examples

library(survival)

colondeaths <- colon[colon$etype == 2, ]
split_colon <- split(colondeaths, colondeaths$rx)
colon_arm1 <- split_colon$Obs

colon1ph <- coxph(Surv(time, status) ~ factor(extent) + nodes + strata(surg)
                   + factor(differ),
                   colon_arm1,
                   x = TRUE, model = TRUE)
surv_pred_info(colon1ph)