riskRegression (version 1.3.7)

CSC: Cause-specific Cox proportional hazard regression

Description

Interface for fitting cause-specific Cox proportional hazard regression models in competing risk.

Usage

CSC(formula, data, cause, survtype = "hazard", fitter = "coxph",
  iid = TRUE, ...)

Arguments

formula

Either a single Hist formula or a list of formulas. If it is a list it must contain as many Hist formulas as there are causes when survtype="hazard" and exactly two formulas when survtype="survival". If it is a list the first formula is used for the cause of interest specific Cox regression and the other formula(s) either for the other cause specific Cox regression(s) or for the Cox regression of the combined event where each cause counts as event. Note that when only one formula is given the covariates enter in exactly the same way into all Cox regression analyses.

data

A data in which to fit the models.

cause

The cause of interest. Defaults to the first cause (see Details).

survtype

Either "hazard" (the default) or "survival". If "hazard" fit cause-specific Cox regression models for all causes. If "survival" fit one cause-specific Cox regression model for the cause of interest and also a Cox regression model for event-free survival.

fitter

Routine to fit the Cox regression models. If coxph use survival::coxph else use rms::cph.

iid

logical. Compute the value of the influence function for each Cox model and store it in the (cause-specific) Cox regression object.

...

Arguments given to coxph.

Value

models

a list with the fitted (cause-specific) Cox regression objects

response

the event history response

eventTimes

the sorted (unique) event times

survtype

the value of survtype

theCause

the cause of interest. see cause

causes

the other causes

%% ...

Details

The causes and their order are determined by prodlim::getStates() applied to the Hist object.

References

J Benichou and Mitchell H Gail. Estimates of absolute cause-specific risk in cohort studies. Biometrics, pages 813--826, 1990.

T.A. Gerds, T.H. Scheike, and P.K. Andersen. Absolute risk regression for competing risks: interpretation, link functions, and prediction. Statistics in Medicine, 31(29):3921--3930, 2012.

See Also

coxph

Examples

library(prodlim)
library(survival)
data(Melanoma)
## fit two cause-specific Cox models
## different formula for the two causes
fit1 <- CSC(list(Hist(time,status)~sex,Hist(time,status)~invasion+epicel+age),
            data=Melanoma, iid = TRUE)
print(fit1)



## model hazard of all cause mortality instead of hazard of type 2 
fit1a <- CSC(list(Hist(time,status)~sex+age,Hist(time,status)~invasion+epicel+log(thick)),
             data=Melanoma,
             survtype="surv")
print(fit1a)

## special case where cause 2 has no covariates
fit1b <- CSC(list(Hist(time,status)~sex+age,Hist(time,status)~1),
             data=Melanoma)
print(fit1b)
predict(fit1b,cause=1,times=100,newdata=Melanoma)


## same formula for both causes
fit2 <- CSC(Hist(time,status)~invasion+epicel+age,
            data=Melanoma)
print(fit2)

## combine a cause-specific Cox regression model for cause 2 
## and a Cox regression model for the event-free survival:
## different formula for cause 2 and event-free survival
fit3 <- CSC(list(Hist(time,status)~sex+invasion+epicel+age,
                 Hist(time,status)~invasion+epicel+age),
            survtype="surv",
            data=Melanoma)
print(fit3)

## same formula for both causes
fit4 <- CSC(Hist(time,status)~invasion+epicel+age,
            data=Melanoma,
            survtype="surv")
print(fit4)

## strata
fit5 <- CSC(Hist(time,status)~invasion+epicel+age+strata(sex),
            data=Melanoma,
            survtype="surv")
print(fit5)

## sanity checks

cox1 <- coxph(Surv(time,status==1)~invasion+epicel+age+strata(sex),data=Melanoma)
cox2 <- coxph(Surv(time,status!=0)~invasion+epicel+age+strata(sex),data=Melanoma)
all.equal(cox1,fit5$models[[1]])
all.equal(cox2,fit5$models[[2]])

## predictions
##
## survtype = "hazard": predictions for both causes can be extracted
## from the same fit
fit2 <- CSC(Hist(time,status)~invasion+epicel+age, data=Melanoma)
predict(fit2,cause=1,newdata=Melanoma[c(17,99,108),],times=c(100,1000,10000))
predictRisk(fit2,cause=1,newdata=Melanoma[c(17,99,108),],times=c(100,1000,10000))
predictRisk(fit2,cause=2,newdata=Melanoma[c(17,99,108),],times=c(100,1000,10000))
predict(fit2,cause=1,newdata=Melanoma[c(17,99,108),],times=c(100,1000,10000))
predict(fit2,cause=2,newdata=Melanoma[c(17,99,108),],times=c(100,1000,10000))

## survtype = "surv" we need to change the cause of interest 
library(survival)
fit5.2 <- CSC(Hist(time,status)~invasion+epicel+age+strata(sex),
            data=Melanoma,
            survtype="surv",cause=2)
## now this does not work
try(predictRisk(fit5.2,cause=1,newdata=Melanoma,times=4))

## but this does
predictRisk(fit5.2,cause=2,newdata=Melanoma,times=100)
predict(fit5.2,cause=2,newdata=Melanoma,times=100)
predict(fit5.2,cause=2,newdata=Melanoma[4,],times=100)