AIWKME {otrKM}

The (S)AIWKME estimator.

Description

Given a predetermined t0 and eta, calculate t0-year potential survival probability based on the (S)AIWKME estimator.

Usage

AIWKME(eta, datalist, ps, prep, t0, smooth = TRUE)

Arguments

eta

The parameters of the regime.

datalist

A list used to calculate the (S)AIWKME estimator including treatment named a, observed time named obs.t, censoring indicator (0, censored) named delta, and baseline covariates used to assign treatment named l. Notice that all the data in the datalist should be ordered by observed time.

ps

A list including the probability of receiving treatment given baseline covariates named fal. Fps.AIWKME can produce ps by positing logistic model.

prep

A list including the augmented terms in the numerator with treatment all to 1 named gamma.num.1 and all to 0 named gamma.num.0 and in the denominator with treatment all to 1 named gamma.den.1 and all to 0 named gamma.den.0; gamma.num.1 and the others are matrix with ordered observed time as rows and patients as columns. Fprep.AIWKME can produce prep by positing Cox proportional hazards model.

t0

A predetermined time.

smooth

A logic variable indicating wether a smoothed estimator should be used.

Details

More details can be found in references.

Value

Estimated potential survival probability given eta and t0.

References

Jiang, R., Lu, W., Song, R., and Davidian, M. (2017) On estimation of optimal treatment regimes for maximizing t‐year survival probability. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 79: 1165-1185. DOI:10.1111/rssb.12201

Examples

# load data
data(simulation)
simulation=simulation[order(simulation$Survival),]

# convert the data into a datalist
datalist=list(z=simulation$Instrument,a=simulation$Treatment,
              obs.t=simulation$Survival,delta=simulation$Status,
              l=cbind(simulation$Covariate1,simulation$Covariate2))

# predetermined t0 and eta
t0=5
eta=c(1,2,3)

# calculate ps and prep
ps=Fps.AIWKME(datalist)
prep=Fprep.AIWKME(datalist, t0)

AIWKME(eta, datalist, ps, prep, t0, smooth=TRUE)