Package 'intccr'

Title: Semiparametric Competing Risks Regression under Interval Censoring
Description: Semiparametric regression models on the cumulative incidence function for interval-censored competing risks data as described in Bakoyannis, Yu, & Yiannoutsos (2017) /doi{10.1002/sim.7350} and the models with missing event types as described in Park, Bakoyannis, Zhang, & Yiannoutsos (2021) \doi{10.1093/biostatistics/kxaa052}. The proportional subdistribution hazards model (Fine-Gray model), the proportional odds model, and other models that belong to the class of semiparametric generalized odds rate transformation models.
Authors: Giorgos Bakoyannis <[email protected]>, Jun Park <[email protected]>
Maintainer: Jun Park <[email protected]>
License: GPL (>= 2)
Version: 3.0.4
Built: 2024-12-21 06:42:41 UTC
Source: CRAN

Help Index


Derivative of B-spline

Description

Generates the derivative of the B-splines basis matrix.

Usage

bs.derivs(
  x,
  derivs = 0,
  df = NULL,
  knots = NULL,
  degree = 3,
  intercept = FALSE,
  Boundary.knots = range(x)
)

Arguments

x

object of B-splines

derivs

a number of derivatives

df

degrees of freedom of B-splines

knots

a vector of internal knots

degree

degrees of B-splines

intercept

a logical vector

Boundary.knots

a vector of boundary knots

Details

The function bs.derivs performs derivatives of B-splines

Value

The function bs.derivs returns a component:

resmat

derivatives of B-spline

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


B-spline Sieve Maximum Likelihood Estimation

Description

Routine that performs B-spline sieve maximum likelihood estimation with linear and nonlinear inequality/equality constraints

Usage

bssmle(formula, data, alpha, k = 1)

Arguments

formula

a formula object relating survival object Surv2(v, u, event) to a set of covariates

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the cause of failure 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the cause of failure 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

Details

The function bssmle performs B-spline sieve maximum likelihood estimation.

Value

The function bssmle returns a list of components:

beta

a vector of the estimated coefficients for the B-splines

varnames

a vector containing variable names

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Z

a set of covariates

Tv

a vector of v

Tu

a vector of u

Bv

a list containing the B-splines basis functions evaluated at v

Bu

a list containing the B-splines basis functions evaluated at v

dBv

a list containing the first derivative of the B-splines basis functions evaluated at v

dBu

a list containing the first derivative of the B-splines basis functions evaluated at u

dmat

a matrix of event indicator functions

Author(s)

Giorgos Bakoyannis, [email protected]

Jun Park, [email protected]


B-spline Sieve Maximum Likelihood Estimation for Interval-Censored Competing Risks Data and Missing Cause of Failure

Description

Routine that performs B-spline sieve maximum likelihood estimation with linear and nonlinear inequality and equality constraints

Usage

bssmle_aipw(formula, aux, data, alpha, k)

Arguments

formula

a formula object relating survival object Surv2(v, u, event) to a set of covariates

aux

auxiliary variables that may be associated with the missingness and the outcome of interest

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the event type 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the event type 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

Details

The function bssmle_aipw performs B-spline sieve maximum likelihood estimation.

Value

The function bssmle_aipw returns a list of components:

beta

a vector of the estimated coefficients for the B-splines

varnames

a vector containing variable names

varnames.aux

a vector containing auxiliary variable names

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Bv

a list containing the B-splines basis functions evaluated at v

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


Least-Squares Estimator of the Information Matrix

Description

Performs the least-squares methods to estimate the information matrix for the estimated regression coefficients

Usage

bssmle_lse(obj)

Arguments

obj

a list of objectives from bssmle

Details

The function bssmle_lse estimates the information matrix for the estimated regression coefficients from the function bssmle using the lease-squares method.

Value

The function bssmle_lse returns a list of components:

Sigma

the estimated variance-covariance matrix for the estimated regression coefficients

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

References

Zhang, Y., Hua, L., and Huang, J. (2010), A spline-based semiparametric maximum likelihood estimation method for the Cox model with interval-censoed data. Scandinavian Journal of Statistics, 37:338-354.


Least-Squares Estimator of the Information Matrix

Description

Performs the least-squares methods to estimate the information matrix for the estimated regression coefficients

Usage

bssmle_lse_lt(obj)

Arguments

obj

a list of objectives from bssmle_lt

Details

The function bssmle_lse_lt estimates the information matrix for the estimated regression coefficients from the function bssmle_lt using the lease-squares method.

Value

The function bssmle_lse_lt returns a list of components:

Sigma

the estimated information matrix for the estimated regression coefficients

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

References

Zhang, Y., Hua, L., and Huang, J. (2010), A spline-based semiparametric maximum likelihood estimation method for the Cox model with interval-censoed data. Scandinavian Journal of Statistics, 37:338-354.


B-spline Sieve Maximum Likelihood Estimation for Left-Truncated and Interval-Censored Competing Risks Data

Description

Routine that performs B-spline sieve maximum likelihood estimation with linear and nonlinear inequality/equality constraints

Usage

bssmle_lt(formula, data, alpha, k = 1)

Arguments

formula

a formula object relating survival object Surv2(w, v, u, event) to a set of covariates

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the event type 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the event type 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

Details

The function bssmle_lt performs B-spline sieve maximum likelihood estimation for left-truncated and interval-censored competing risks data.

Value

The function bssmle_lt returns a list of components:

beta

a vector of the estimated coefficients

varnames

a vector containing variable names

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Z

a design matrix

Tw

a vector of w

Tv

a vector of v

Tu

a vector of u

Bw

a list containing the B-splines basis functions evaluated at w

Bv

a list containing the B-splines basis functions evaluated at v

Bu

a list containing the B-splines basis functions evaluated at u

dBw

a list containing the first derivative of the B-splines basis functions evaluated at w

dBv

a list containing the first derivative of the B-splines basis functions evaluated at v

dBu

a list containing the first derivative of the B-splines basis functions evaluated at u

dmat

a matrix of event indicator functions

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


Bootstrap varince-covariance estimation

Description

Bootstrap varince estimation for the estimated regression coefficients

Usage

bssmle_se(formula, data, alpha, k = 1, do.par, nboot, objfun)

Arguments

formula

a formula object relating survival object Surv2(v, u, event) to a set of covariates

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the cause of failure 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the cause of failure 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

do.par

using parallel computing for bootstrap calculation. If do.par = TRUE, parallel computing will be used during the bootstrap estimation of the variance-covariance matrix for the regression parameter estimates.

nboot

a number of bootstrap samples for estimating variances and covariances of the estimated regression coefficients. If nboot = 0, the function ciregic does dot perform bootstrap estimation of the variance matrix of the regression parameter estimates and returns NA in the place of the estimated variance matrix of the regression parameter estimates.

objfun

an option to select estimating function

Details

The function bssmle_se estimates bootstrap standard errors for the estimated regression coefficients from the function bssmle, bssmle_lt, ro bssmle_ltir.

Value

The function bssmle_se returns a list of components:

notconverged

a list of number of bootstrap samples that did not converge

numboot

a number of bootstrap converged

Sigma

an estimated bootstrap variance-covariance matrix of the estimated regression coefficients

Author(s)

Giorgos Bakoyannis, [email protected]

Jun Park, [email protected]


Bootstrap varince-covariance estimation for interval-censored competing risks data and missing cause of failure

Description

Bootstrap varince estimation for the estimated regression coefficients

Usage

bssmle_se_aipw(formula, aux, data, alpha, k, do.par, nboot, w.cores = NULL)

Arguments

formula

a formula object relating survival object mSurv(v, u, event) to a set of covariates

aux

auxiliary variables that may be associated with the missingness and the outcome of interest

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the event type 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the event type 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

do.par

using parallel computing for bootstrap calculation. If do.par = TRUE, parallel computing will be used during the bootstrap estimation of the variance-covariance matrix for the regression parameter estimates.

nboot

a number of bootstrap samples for estimating variances and covariances of the estimated regression coefficients. If nboot = 0, the function ciregic does dot perform bootstrap estimation of the variance matrix of the regression parameter estimates and returns NA in the place of the estimated variance matrix of the regression parameter estimates.

w.cores

a number of cores that are assigned (the default is NULL)

Details

The function bssmle_aipw_se estimates bootstrap standard errors for the estimated regression coefficients from the function bssmle.

Value

The function bssmle_aipw_se returns a list of components:

notconverged

a list of number of bootstrap samples that did not converge

numboot

a number of bootstrap converged

Sigma

an estimated bootstrap variance-covariance matrix of the estimated regression coefficients

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


Competing Risks Regression with Interval-Censored Data

Description

The function ciregic performs semiparametric regression on cumulative incidence function with interval-censored competing risks data. It fits the proportional subdistribution hazards model (Fine-Gray model), the proportional odds model, and other models that belong to the class of semiparametric generalized odds rate transformation models. The standard errors for the estimated regression coefficients are estimated by a choice of options: 1) the bootstrapping method or 2) the least-squares method.

Usage

ciregic(formula, data, alpha, k = 1, do.par, nboot, ...)

Arguments

formula

a formula object relating the survival object Surv2(v, u, event) to a set of covariates

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the cause of failure 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the cause of failure 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

do.par

an option to use parallel computing for bootstrap. If do.par = TRUE, parallel computing will be used during the bootstrap estimation of the variance-covariance matrix for the regression parameter estimates.

nboot

a number of bootstrap samples for estimating variances and covariances of the estimated regression coefficients. If nboot = 0, the function ciregic provides the variance estimator of the regression parameter estimates using the least-squares method and does not perform the bootstrap method.

...

further arguments

Details

The formula for the model has the form of response ~ predictors. The response in the formula is a Surv2(v, u, event) object where v is the last observation time prior to the failure, u is the first observation time after the failure, and event is the event or censoring indicator. event should include 0, 1 or 2, denoting right-censoring, failure from cause 1 and failure from cause 2, respectively. If event=0 (i.e. right-censored observation) then u is not included in any calculation as it corresponds to \infty. The user can provide any value in u for the right-censored cases, even NA. The function ciregic fits models that belong to the class of generalized odds rate transformation models which includes the proportional subdistribution hazards or the Fine-Gray model and the proportional odds model. The parameter α=(α1,α2)\alpha=(\alpha1, \alpha2) defines the link function/model to be fitted for cause of failure 1 and 2, respectively. A value of 0 corresponds to the Fine-Gray model and a value of 1 corresponds to the proportional odds model. For example, if α=(0,1)\alpha=(0,1) then the function ciregic fits the Fine-Gray model for cause 1 and the proportional odds model for cause 2.

Value

The function ciregic provides an object of class ciregic with components:

varnames

a vector containing variable names

coefficients

a vector of the regression coefficient estimates

gamma

a vector of the estimated coefficients for the B-splines

vcov

a variance-covariance matrix of the estimated regression coefficients

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Bv

a list containing the B-splines basis functions evaluated at v

numboot

a number of converged bootstrap

notconverged

a list of number of bootstrap samples that did not converge

call

a matched call

Author(s)

Giorgos Bakoyannis, [email protected]

Jun Park, [email protected]

References

Bakoyannis, G., Yu, M., and Yiannoutsos C. T. (2017). Semiparametric regression on cumulative incidence function with interval-censored competing risks data. Statistics in Medicine, 36:3683-3707.

Fine, J. P. and Gray, R. J. (1999). A proportional hazards model for the subdistribution of a competing risk. Journal of the American Statistical Association, 94:496-509.

See Also

summary.ciregic for the summarized results and predict.ciregic for value of the predicted cumulative incidence functions. coef and vcov are the generic functions. dataprep for reshaping data from a long format to a suitable format to be used in the function ciregic.

Examples

## Not run: 
## Set seed in order to have reproducibility of the bootstrap standard error estimate
set.seed(1234)

## Reshaping data from a long format to a suitable format
newdata <- dataprep(data = longdata, ID = id, time = t,
                    event = c, Z = c(z1, z2))
## Estimation of regression parameters only. No bootstrap variance estimation.
## with 'newdata'
fit <- ciregic(formula = Surv2(v = v, u = u, event = c) ~ z1 + z2, data = newdata,
               alpha = c(1, 1), nboot = 0, do.par = FALSE)
fit

## Bootstrap variance estimation based on 50 replications
fit <- ciregic(formula = Surv2(v = v, u = u, event = c) ~ z1 + z2, data = newdata,
               alpha = c(1, 1), nboot = 50, do.par = FALSE)

## End(Not run)
## Note that the user can use parallel computing to decrease
## the computation time of the bootstrap variance-covariance
## estimation (e.g. nboot = 50)

## Summarize semiparametric regression model
summary(fit)

## Predict and draw plot the cumulative incidence function evaluated at z1 = 1 and z2 = 0.5
t <- seq(from = 0, to = 2.8, by = 2.8 / 99)
pred <- predict(object = fit, covp = c(1, 0.5), times = t)
pred
plot(pred$t, pred$cif1, type = "l", ylim = c(0, 1))
points(pred$t, pred$cif2, type = "l", col = 2)

Competing Risks Regression with Interval-Censored Data and Missing Cause of Failure

Description

The function ciregic_aipw performs semiparametric regression on cumulative incidence function with interval-censored competing risks data in the presence of missing cause of failure. It fits the proportional subdistribution hazards model (Fine-Gray model), the proportional odds model, and other models that belong to the class of semiparametric generalized odds rate transformation models. The estimates have double robustness property, which means that the estimators are consistent even if either the model for the probability of missingness or the model for the probability of the cause of failure is misspecified under the missing at random assumption.

Usage

ciregic_aipw(
  formula,
  aux = NULL,
  data,
  alpha,
  k = 1,
  do.par,
  nboot,
  w.cores = NULL,
  ...
)

Arguments

formula

a formula object relating the survival object Surv2(v, u, event) to a set of covariates

aux

auxiliary variable(s) that may be associated with the missingness and the outcome of interest

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the event type 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the event type 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

do.par

an option to use parallel computing for bootstrap. If do.par = TRUE, parallel computing will be used during the bootstrap estimation of the variance-covariance matrix for the regression parameter estimates.

nboot

a number of bootstrap samples for estimating variances and covariances of the estimated regression coefficients. If nboot = 0, the function ciregic_aipw does not perform bootstrap estimation of the variance-covariance matrix of the regression parameter estimates and returns NA in the place of the estimated variance-covariance matrix of the regression parameter estimates.

w.cores

a number of cores that are assigned (the default is NULL)

...

further arguments

Details

The formula for the model has the form of response ~ predictors. The response in the formula is a Surv2(v, u, event) object where v is the last observation time prior to the event, u is the first observation time after the event, and event is the event or censoring indicator. event should include 0, 1 or 2, denoting right-censoring, event type 1 and 2, respectively. If event=0 (i.e. right-censored observation) then u is not included in any calculation as it corresponds to \infty. The user can provide any value in u for the right-censored cases, even NA. The function ciregic_aipw fits models that belong to the class of generalized odds rate transformation models which includes the proportional subdistribution hazards or the Fine-Gray model and the proportional odds model. The parameter α=(α1,α2)\alpha=(\alpha1, \alpha2) defines the link function/model to be fitted for event 1 and 2, respectively. A value of 0 corresponds to the Fine-Gray model and a value of 1 corresponds to the proportional odds model. For example, if α=(0,1)\alpha=(0,1) then the function ciregic_aipw fits the Fine-Gray model for the event type 1 and the proportional odds model for the event type 2.

Value

The function ciregic_aipw provides an object of class ciregic_aipw with components:

varnames

a vector containing variable names

varnames.aux

a vector containing auxiliary variable names

coefficients

a vector of the regression coefficient estimates

gamma

a vector of the estimated coefficients for the B-splines

vcov

a variance-covariance matrix of the estimated regression coefficients

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Bv

a list containing the B-splines basis functions evaluated at v

numboot

a number of converged bootstrap

notconverged

a list of number of bootstrap samples that did not converge

call

a matched call

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

References

Bakoyannis, G., Yu, M., and Yiannoutsos C. T. (2017). Semiparametric regression on cumulative incidence function with interval-censored competing risks data. Statistics in Medicine, 36:3683-3707.

Fine, J. P. and Gray, R. J. (1999). A proportional hazards model for the subdistribution of a competing risk. Journal of the American Statistical Association, 94:496-509.

See Also

summary.ciregic_aipw for the summarized results and predict.ciregic_aipw for value of the predicted cumulative incidence functions. coef and vcov are the generic functions. dataprep function for reshaping data from a long format to a suitable format to be used in the function ciregic_aipw.

Examples

## Not run: 
## Set seed in order to have reproducibility of the bootstrap standard error estimate
set.seed(1234)

## Estimation of regression parameters only. No bootstrap variance estimation.
## with 'simdata_aipw'
data(simdata_aipw)
fit_aipw <- ciregic_aipw(formula = Surv2(v = v, u = u, event = c) ~ z1 + z2, aux = a,
                         data = simdata_aipw, alpha = c(1, 1), nboot = 0,
                         do.par = FALSE)
fit_aipw
## Bootstrap variance estimation based on 50 replications
fit_aipw <- ciregic_aipw(formula = Surv2(v = v, u = u, event = c) ~ z1 + z2, aux = a,
                         data = simdata_aipw, alpha = c(1, 1), k = 1, nboot = 50,
                         do.par = FALSE)

## End(Not run)
## Note that the user can use parallel computing to decrease
## the computation time of the bootstrap variance-covariance
## estimation (e.g. nboot = 50)

## Summarize semiparametric regression model
summary(fit_aipw)

## Predict and draw plot the cumulative incidence function evaluated at z1 = 1 and z2 = 0.5
t <- seq(from = 0, to = 2.8, by = 2.8 / 99)
pred <- predict(object = fit_aipw, covp = c(1, 0.5), times = t)
pred
plot(pred$t, pred$cif1, type = "l", ylim = c(0, 1))
points(pred$t, pred$cif2, type = "l", col = 2)

Competing Risks Regression with Left-truncated and Interval-Censored Data

Description

The function ciregic_lt performs semiparametric regression on cumulative incidence function with left-truncated and interval-censored competing risks data. It fits the proportional subdistribution hazards model (Fine-Gray model), the proportional odds model, and other models that belong to the class of semiparametric generalized odds rate transformation models. The least-square method is implemented to estimate the standard error of the regression coefficients.

Usage

ciregic_lt(formula, data, alpha, k = 1, do.par, nboot, ...)

Arguments

formula

a formula object relating the survival object Surv2(v, u, w, event) to a set of covariates

data

a data frame that includes the variables named in the formula argument

alpha

α=(α1,α2)\alpha = (\alpha1, \alpha2) contains parameters that define the link functions from class of generalized odds-rate transformation models. The components α1\alpha1 and α2\alpha2 should both be 0\ge 0. If α1=0\alpha1 = 0, the user assumes the proportional subdistribution hazards model or the Fine-Gray model for the cause of failure 1. If α2=1\alpha2 = 1, the user assumes the proportional odds model for the cause of failure 2.

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

do.par

an option to use parallel computing for bootstrap. If do.par = TRUE, parallel computing will be used during the bootstrap estimation of the variance-covariance matrix for the regression parameter estimates.

nboot

a number of bootstrap samples for estimating variances and covariances of the estimated regression coefficients. If nboot = 0, the function ciregic_lt returns a closed-form variance estimator using the least-squares method and does not perform bootstrap estimation of the variance-covariance matrix of the regression parameter estimates. For nboot 1\ge 1, the function ciregic_lt returns the boostrap variance estimator of the regression parameter estimates.

...

further arguments

Details

The function ciregic_lt is capable of analyzing left-truncated and interval-censored competing risks data. A triplet of time points (w, v, u) is required if an observation is left-truncated and interval-censored. A part of left-truncation is also allowed by defining w = 0 for interval-censored only observation. The formula for the model has the form of response ~ predictors. The response in the formula is a Surv2(v, u, w, event) object where w is a left-truncation time, v is the last observation time prior to the failure, u is the first observation time after the failure, and event is the event or censoring indicator. event should include 0, 1 or 2, denoting right-censoring, failure from cause 1 and failure from cause 2, respectively. If event=0 (i.e. right-censored observation) then u is not included in any calculation as it corresponds to \infty. The user can provide any value in u for the right-censored cases, even NA. The function ciregic_lt fits models that belong to the class of generalized odds rate transformation models which includes the proportional subdistribution hazards or the Fine-Gray model and the proportional odds model. The parameter α=(α1,α2)\alpha=(\alpha1, \alpha2) defines the link function/model to be fitted for cause of failure 1 and 2, respectively. A value of 0 corresponds to the Fine-Gray model and a value of 1 corresponds to the proportional odds model. For example, if α=(0,1)\alpha=(0,1) then the function ciregic_lt fits the Fine-Gray model for cause 1 and the proportional odds model for cause 2.

Value

The function ciregic_lt provides an object of class ciregic_lt with components:

varnames

a vector containing variable names

coefficients

a vector of the regression coefficient estimates

gamma

a vector of the estimated coefficients for the B-splines

vcov

a variance-covariance matrix of the estimated regression coefficients

alpha

a vector of the link function parameters

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Bv

a list containing the B-splines basis functions evaluated at v

numboot

a number of converged bootstrap

notconverged

a list of number of bootstrap samples that did not converge

call

a matched call

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

References

Bakoyannis, G., Yu, M., and Yiannoutsos C. T. (2017). Semiparametric regression on cumulative incidence function with interval-censored competing risks data. Statistics in Medicine, 36:3683-3707.

Fine, J. P. and Gray, R. J. (1999). A proportional hazards model for the subdistribution of a competing risk. Journal of the American Statistical Association, 94:496-509.

See Also

summary.ciregic_lt for the summarized results and predict.ciregic_lt for value of the predicted cumulative incidence functions. coef and vcov are the generic functions. dataprep for reshaping data from a long format to a suitable format to be used in the function ciregic_lt.

Examples

## Not run: 
## Set seed in order to have reproducibility of the bootstrap standard error estimate
set.seed(1234)

## Reshaping data from a long format to a suitable format
newdata <- dataprep_lt(data = longdata_lt, ID = id, time = t, W = w,
                       event = c, Z = c(z1, z2))
## Estimation of regression parameters only. No bootstrap variance estimation.
## with 'newdata'
fit_lt <- ciregic_lt(formula = Surv2(v = v, u = u, w = w, event = c) ~ z1 + z2, data = newdata,
                    alpha = c(1, 1), nboot = 0, do.par = FALSE)
fit_lt

## Bootstrap variance estimation based on 50 replications
fit_lt <- ciregic_lt(formula = Surv2(v = v, u = u, w = w, event = c) ~ z1 + z2, data = newdata,
                    alpha = c(1, 1), nboot = 50, do.par = FALSE)

## End(Not run)
## Note that the user can use parallel computing to decrease
## the computation time of the bootstrap variance-covariance
## estimation (e.g. nboot = 50)

## Summarize semiparametric regression model
summary(fit_lt)

## Predict and draw plot the cumulative incidence function evaluated at z1 = 1 and z2 = 0.5
mint <- fit_lt$tms[1]
maxt <- fit_lt$tms[2]
pred <- predict(object = fit_lt, covp = c(1, 0.5),
                times = seq(mint, maxt, by = (maxt - mint) / 99))
pred
plot(pred$t, pred$cif1, type = "l", ylim = c(0, 1))
points(pred$t, pred$cif2, type = "l", col = 2)

Data manipulation

Description

The function dataprep reshapes data from a long format to a ready-to-use format to be used directly in the function ciregic.

Usage

dataprep(data, ID, time, event, Z)

Arguments

data

a data frame that includes the variables named in the ID, time, event, and z arguments

ID

a variable indicating individuals' ID

time

a variable indicating observed time points

event

a vector of event indicator. If an observation is righ-censored, event = 0; otherwise, event = 1 or event = 2, where 1 represents the first cause of failure, and 2 represents the second cause of failure. The current version of package only allows two causes of failure.

Z

a vector of variables indicating name of covariates

Details

The function dataprep provides a ready-to-use data format that can be directly used in the function ciregic. The returned data frame consists of id, v, u, c, and covariates as columns. The v and u indicate time window with the last observation time before the event and the first observation after the event. The c represents a type of event, for example, c = 1 for the first cause of failure, c = 2 for the second cause of failure, and c = 0 for the right-censored. For individuals having one time record with the event, the lower bound v will be replaced by zero, for example (0, v]. For individuals having one time record without the event, the upper bound u will be replaced by Inf, for example (v, Inf].

Value

a data frame

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

Examples

library(intccr)
dataprep(data = longdata, ID = id, time = t, event = c, Z = c(z1, z2))

Data preparation

Description

The function dataprep_lt reshapes data from a long format to a ready-to-use format to be used directly in the function ciregic_lt.

Usage

dataprep_lt(data, ID, W, time, event, Z)

Arguments

data

a data frame that includes the variables named in the ID, time, event, and z arguments

ID

a variable indicating individuals' ID

W

a vector of left-truncated time points

time

a variable indicating observed time points

event

a vector of event indicator. If an observation is righ-censored, event = 0; otherwise, event = 1 or event = 2, where 1 represents the first cause of failure, and 2 represents the second cause of failure. The current version of package only allows two causes of failure.

Z

a vector of variables indicating name of covariates

Details

The function dataprep_lt provides a ready-to-use data format that can be directly used in the function ciregic_lt. The returned data frame consists of id, v, u, c, and covariates as columns. The v and u indicate time window with the last observation time before the event and the first observation after the event. The c represents a type of event, for example, c = 1 for the first cause of failure, c = 2 for the second cause of failure, and c = 0 for the right-censored. For individuals having one time record with the event, the lower bound v will be replaced by zero, for example (0, v]. For individuals having one time record without the event, the upper bound u will be replaced by Inf, for example (v, Inf].

Value

a data frame

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


Derivative of B-spline

Description

Generates the derivative of the B-splines basis matrix.

Usage

dbs(
  x,
  derivs = 1L,
  df = NULL,
  knots = NULL,
  degree = 3L,
  intercept = FALSE,
  Boundary.knots = range(x, na.rm = TRUE)
)

Arguments

x

object of B-splines

derivs

a number of derivatives

df

degrees of freedom of B-splines

knots

a vector of internal knots

degree

degrees of B-splines

intercept

a logical vector

Boundary.knots

a vector of boundary knots

Details

The function dbs performs derivatives of B-splines

Value

The function dbs returns a component:

dMat

B-spline matrix

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]


Output of ciregic

Description

Object contains the output of the function ciregic. Standard errors were estimated by the least-squares method.

Usage

fit

Format

A list of components.

Examples

fit

Output of ciregic_aipw

Description

A list of outputs containing the last time prior to the event, the first time after the event, cause of failure with 50%50\% of missingness, and covariates.

Usage

fit_aipw

Format

A list of 14:

call

a matched call

varnames

a vector containing variable names

varnames.aux

a vector containing auxiliary variable names

coefficients

a vector of the regression coefficient estimates

gamma

a vector of the estimated coefficients for the B-splines

vcov

a variance-covariance matrix of the estimated regression coefficients

alpha

a vector of the link function parameters

k

a parameter that controls the number of knots in the B-spline

loglikelihood

a loglikelihood of the fitted model

convergence

an indicator of convegence

tms

a vector of the minimum and maximum observation times

Bv

a list containing the B-splines basis functions evaluated at v

notconverged

a list of number of bootstrap samples not converged

Examples

fit_aipw

Output of ciregic_lt

Description

Object contains the output of the function ciregic_lt. Standard errors were estimated by the least-squares method.

Usage

fit_lt

Format

A list of components.

Examples

fit_lt

Simulated interval-censored competing risks data - long format

Description

The data containing the subject id, series of time points, cause of failure, and covariates with 200 observations.

Usage

longdata

Format

A data frame with 868 rows and 5 variables.

Examples

library(intccr)
data(longdata)

Simulated left-truncated and interval-censored competing risks data - long format

Description

Data containing observation time points, a left-truncation time, cause of failure, and baseline covariates with 275 observations.

Usage

longdata_lt

Format

A data frame with 275 unique individuals and 6 variables.

Examples

library(intccr)
data(longdata_lt)

Initial values for the sieve maximum likelihood estimation

Description

The function naive_b provides a vector of initial values for the B-spline sieve maximum likelihood estimation.

Usage

naive_b(data, w = NULL, v, u, c, q, k = 1)

Arguments

data

a data frame that includes the variables named in each argument

w

a left-truncation time (default is w = NULL.)

v

the last observation time prior to the failure

u

the first observation time after the failure

c

an indicator of cause of failure, for example, if an observation is righ-censored, event = 0; otherwise, event = 1 or event = 2, where 1 represents the first cause of failure, and 2 represents the second cause of failure. The current version of package only allows for two causes of failure.

q

a number of parameters in design matrix

k

a parameter that controls the number of knots in the B-spline with 0.50.5 \lek1\le 1

Details

The function naive_b provides initial values for the optimization procedure.

Value

Initial values of B-spline estimation

b

a vector of the initial values to be used in the optimization process

Author(s)

Giorgos Bakoyannis, [email protected]

Jun Park, [email protected]

Examples

attach(simdata)
intccr:::naive_b(data = simdata, v = v, u = u, c = c, q = 2)

Covariate-Specific Cumulative Incidence Prediction

Description

predict method for class ciregic. It provides the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Usage

## S3 method for class 'ciregic'
predict(object, covp, times, ...)

Arguments

object

an object of class ciregic, which is a result of a call to ciregic

covp

a desired values for covariates

times

time points that user wants to predict value of cumulative incidence function

...

further arguments

Details

predict.ciregic returns the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Value

The function predict.ciregic returns a list of predicted values of the model from object.

t

time points

cif1

the predicted value of cumulative incidence function for the event type 1

cif2

the predicted value of cumulative incidence function for the event type 2

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic and summary of the fitted semiparametric regression model summary.ciregic

Examples

## Continuing the ciregic(...) example
pfit <- predict(object = fit, covp = c(1, 0.5), times = c(0.1, 0.15, 0.5, 0.7))
pfit
mint <- fit$tms[1]
maxt <- fit$tms[2]
pfit1 <- predict(object = fit, covp = c(1, 0.5),
                 times = seq(mint, maxt, by = (maxt-mint)/99))
plot(pfit1$t, pfit1$cif1, ylim = c(0, 1), type = "l")
lines(pfit1$t, pfit1$cif2, ylim = c(0, 1), lty = 2, col = 2)

Covariate-Specific Cumulative Incidence Prediction

Description

predict method for class ciregic_aipw. It provides the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Usage

## S3 method for class 'ciregic_aipw'
predict(object, covp, times, ...)

Arguments

object

an object of class ciregic_aipw, which is a result of a call to ciregic_aipw

covp

a desired values for covariates

times

time points that user wants to predict value of cumulative incidence function

...

further arguments

Details

predict.ciregic_aipw returns the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Value

The function predict.ciregic_aipw returns a list of predicted values of the model from object.

t

time points

cif1

the predicted value of cumulative incidence function for the event type 1

cif2

the predicted value of cumulative incidence function for the event type 2

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_aipw and summary of the fitted semiparametric regression model summary.ciregic_aipw

Examples

## Continuing the ciregic_aipw(...) example
pfit <- predict(object = fit_aipw, covp = c(1, 0.5), times = c(0.1, 0.15, 0.5, 0.7))
pfit
mint <- fit_aipw$tms[1]
maxt <- fit_aipw$tms[2]
pfit1 <- predict(object = fit_aipw, covp = c(1, 0.5),
                 times = seq(mint, maxt, by = (maxt - mint) / 99))
plot(pfit1$t, pfit1$cif1, ylim = c(0, 1), type = "l")
lines(pfit1$t, pfit1$cif2, ylim = c(0, 1), lty = 2, col = 2)

Covariate-Specific Cumulative Incidence Prediction

Description

predict method for class ciregic_lt. It provides the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Usage

## S3 method for class 'ciregic_lt'
predict(object, covp, times, ...)

Arguments

object

an object of class ciregic_lt, which is a result of a call to ciregic_lt

covp

a desired values for covariates

times

time points that user wants to predict value of cumulative incidence function

...

further arguments

Details

predict.ciregic_lt returns the predicted cumulative incidence function for a given covariate pattern and timepoint(s).

Value

The function predict.ciregic_lt returns a list of predicted values of the model from object.

t

time points

cif1

the predicted value of cumulative incidence function for the event type 1

cif2

the predicted value of cumulative incidence function for the event type 2

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_lt and summary of the fitted semiparametric regression model summary.ciregic_lt

Examples

## Continuing the ciregic_lt(...) example
pfit <- predict(object = fit_lt, covp = c(1, 0.5), times = c(0.1, 0.15, 0.5, 0.7))
pfit
mint <- fit_lt$tms[1]
maxt <- fit_lt$tms[2]
pfit1 <- predict(object = fit_lt, covp = c(1, 0.5),
                 times = seq(mint, maxt, by = (maxt - mint) / 99))
plot(pfit1$t, pfit1$cif1, ylim = c(0, 1), type = "l")
lines(pfit1$t, pfit1$cif2, ylim = c(0, 1), lty = 2, col = 2)

Prediction of derivative of B-spline

Description

Evaluates the derivative of the B-splines basis matrix at given values.

Usage

## S3 method for class 'dbs'
predict(object, newx)

Arguments

object

returned object of B-splines

newx

a vector of points

Details

The function predict is a generic function of bs.derivs

Value

The function predict returns a predicted B-splies.

Author(s)

Giorgos Bakoyannis, [email protected]

Jun Park, [email protected]


Artificial HIV dataset

Description

Artificial dataset that was simulated to resemble the HIV study on loss to HIV care and death in sub-Saharan Africa, that was presented in Bakoyannis, Yu, & Yiannoutsos (2017). It contains subject id, observation times, cause of failure, and covariates.

Usage

pseudo.HIV.long

Format

A data frame with 22710 rows and 6 variables.

References

Bakoyannis, G., Yu, M., and Yiannoutsos C. T. (2017). Semiparametric regression on cumulative incidence function with interval-censored competing risks data. Statistics in Medicine, 36:3683-3707.

Examples

head(pseudo.HIV.long, n = 20)

Simulated interval-censored competing risks data with 2 covariates - wide format

Description

The data containing the idividual identification number, the last time point prior to the event, the first time point after the event, cause of failure, and covariates with 200 observations.

Usage

simdata

Format

A data frame with 200 rows and 6 variables.

id

subject id

v

the last observation time prior to the event

u

the first observation time after the event

c

cause of failure with missing

z1

binary variable

z2

continuous variable

Examples

library(intccr)
data(simdata)

Simulated interval censored data with 2 covariates in the presence of 50%50\% of missing cause of failure - wide format

Description

The dataset containing the individual identification number, the last time prior to the event, the first time after the event, cause of failure with 50%50\% of missingness, and covariates.

Usage

simdata_aipw

Format

A data frame with 200 rows and 7 variables:

id

subject id

v

the last observation time prior to the event

u

the first observation time after the event

c

cause of failure with missing

z1

binary variable

z2

continuous variable

a

auxiliary variable

Examples

library(intccr)
data(simdata_aipw)

Simulated left-truncated and interval-censored competing risks data with 2 covariates - wide format

Description

The data containing the individual identification number, the left-truncated time, the last and first observation time prior to the event and after the event, cause of failure, and baseline covariates with 275 observations.

Usage

simdata_lt

Format

A data frame with 275 unique individuals and 7 variables.

id

subject id

w

the left truncation time

v

the last observation time prior to the event

u

the first observation time after the event

c

cause of failure with missing

z1

binary variable

z2

continuous variable

Examples

library(intccr)
data(simdata_lt)

Summary of ciregic

Description

summary method for class ciregic

Usage

## S3 method for class 'ciregic'
summary(object, ...)

Arguments

object

an object of class ciregic, which is a result of a call to ciregic

...

further arguments

Details

The function summary.ciregic returns the coefficients, bootstrap standard errors, and etc. Additionally, 'significance star' is included.

Value

The function summary.ciregic returns a list of summary statistics of the model from object.

varnames

a vector containing variable names

coefficients

a vector of the regression coefficient estimates

se

a bootstrap standard error of the coefficients

z

z value of the estimated coefficients

p

p value of the estimated coefficients

call

a matched call

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic and values of the predicted cumulative incidence functions predict.ciregic

Examples

## Continuing the ciregic(...) example
sfit <- summary(fit)
sfit

Summary of ciregic_aipw

Description

summary method for class ciregic_aipw

Usage

## S3 method for class 'ciregic_aipw'
summary(object, ...)

Arguments

object

an object of class ciregic_aipw, which is a result of a call to ciregic_aipw

...

further arguments

Details

The function summary.ciregic_aipw returns the coefficients, bootstrap standard errors, and etc. Additionally, 'significance star' is included.

Value

The function summary.ciregic_aipw returns a list of summary statistics of the model from object.

varnames

a vector containing variable names

coefficients

a vector of the regression coefficient estimates

se

a bootstrap standard error of the coefficients

z

z value of the estimated coefficients

p

p value of the estimated coefficients

call

a matched call

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_aipw and values of the predicted cumulative incidence functions predict.ciregic_aipw

Examples

## Continuing the ciregic_aipw(...) example
sfit <- summary(fit_aipw)
sfit

Summary of ciregic_lt

Description

summary method for class ciregic_lt

Usage

## S3 method for class 'ciregic_lt'
summary(object, ...)

Arguments

object

an object of class ciregic_lt, which is a result of a call to ciregic_lt

...

further arguments

Details

The function summary.ciregic_lt returns the coefficients, bootstrap standard errors, and etc. Additionally, 'significance star' is included.

Value

The function summary.ciregic_lt returns a list of summary statistics of the model from object.

varnames

a vector containing variable names

coefficients

a vector of the regression coefficient estimates

se

a bootstrap standard error of the coefficients

z

z value of the estimated coefficients

p

p value of the estimated coefficients

call

a matched call

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_lt and values of the predicted cumulative incidence functions predict.ciregic_lt

Examples

## Continuing the ciregic_lt(...) example
sfit_lt <- summary(fit_lt)
sfit_lt

Creating data frame

Description

The function Surv2 generates the survival object to be treated as the response from ciregic.

Usage

Surv2(v, u, w = NULL, sub = NULL, event)

Arguments

v

the last observation time prior to the failure; 0vu0\le v \le u

u

the first observation time after the failure; u0u \ge 0

w

a left truncation time or delayed entry time. The default setting is w = NULL for non left-truncated data.

sub

an indicator variable in the data set. It is an optional argument for interval-censored competing risks data and missing cause of failure, and the default is NULL. sub = 1 for the observations that are subject to missingness and sub = 0 elsewhere.

event

an indicator of cause of failure. If an observation is righ-censored, event = 0; otherwise, event = 1 or event = 2, where 1 represents the first cause of failure, and 2 represents the second cause of failure. The current version of package only allows for two causes of failure.

Details

The function Surv2 provides a response data frame which is used in the function ciregic and ciregic_lt. For interval-censored competing risks data, the function Surv2 must use three parameters (v, u, c). For left-truncated and interval censored competing risks data, the function Surv2 must use four parameters (v, u, w, c). If data are partially left-truncated, but all interval-censored, w = 0 for only interval-censored competing risks data.

Value

data frame

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

Examples

attach(simdata)
Surv2(v = v, u = u, event = c)
attach(simdata_lt)
Surv2(v = v, u = u, w = w, event = c)

Variance-covariance matrix of ciregic

Description

vcov method for class ciregic

Usage

## S3 method for class 'ciregic'
vcov(object, ...)

Arguments

object

an object of class ciregic, which is a result of a call to ciregic

...

further arguments

Details

The function vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic, summary of the fitted semiparametric regression model summary.ciregic, and values of predicted cumulative incidence functions predict.ciregic

Examples

## Continuing the ciregic(...) example
vcov(fit)

Variance-covariance matrix of ciregic_aipw

Description

vcov method for class ciregic_aipw

Usage

## S3 method for class 'ciregic_aipw'
vcov(object, ...)

Arguments

object

an object of class ciregic_aipw, which is a result of a call to ciregic_aipw

...

further arguments

Details

The function vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_aipw, summary of the fitted semiparametric regression model summary.ciregic_aipw, and values of predicted cumulative incidence functions predict.ciregic_aipw

Examples

## Continuing the ciregic_aipw(...) example
vcov(fit_aipw)

Variance-covariance matrix of ciregic_lt

Description

vcov method for class ciregic_lt

Usage

## S3 method for class 'ciregic_lt'
vcov(object, ...)

Arguments

object

an object of class ciregic_lt, which is a result of a call to ciregic_lt

...

further arguments

Details

The function vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_lt, summary of the fitted semiparametric regression model summary.ciregic_lt, and values of predicted cumulative incidence functions predict.ciregic_lt

Examples

## Continuing the ciregic_lt(...) example
vcov(fit_lt)

Variance-covariance matrix of summary.ciregic

Description

vcov method for class summary.ciregic

Usage

## S3 method for class 'summary.ciregic'
vcov(object, ...)

Arguments

object

an object of class summary.ciregic, which is a result of a call to ciregic

...

further arguments

Details

The vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic, summary of the fitted semiparametric regression model summary.ciregic, and values of the predicted cumulative incidence functions predict.ciregic

Examples

## Continuing the ciregic(...) example
vcov(summary(fit))

Variance-covariance matrix of summary.ciregic_aipw

Description

vcov method for class summary.ciregic_aipw

Usage

## S3 method for class 'summary.ciregic_aipw'
vcov(object, ...)

Arguments

object

an object of class summary.ciregic_aipw, which is a result of a call to ciregic_aipw

...

further arguments

Details

The vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_aipw, summary of the fitted semiparametric regression model summary.ciregic_aipw, and values of the predicted cumulative incidence functions predict.ciregic_aipw

Examples

## Continuing the ciregic_aipw(...) example
vcov(summary(fit_aipw))

Variance-covariance matrix of summary.ciregic_lt

Description

vcov method for class summary.ciregic_lt

Usage

## S3 method for class 'summary.ciregic_lt'
vcov(object, ...)

Arguments

object

an object of class summary.ciregic_lt, which is a result of a call to ciregic_lt

...

further arguments

Details

The vcov returns the variance-covariance matrix of the fitted semiparametric regression model.

Value

The estimated bootstrap variance-covariance matrix

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic_lt, summary of the fitted semiparametric regression model summary.ciregic_lt, and values of the predicted cumulative incidence functions predict.ciregic_lt

Examples

## Continuing the ciregic_lt(...) example
vcov(summary(fit_lt))

Wald test for ciregic and ciregic_lt

Description

waldtest for class ciregic or ciregic_lt. This provides the result of Wald test for the fitted model from the function ciregic or ciregic_lt.

Usage

waldtest(obj1, obj2 = NULL, ...)

Arguments

obj1

an object of the fitted model in ciregic or ciregic_lt

obj2

an object of the fitted model in ciregic or ciregic_lt, the default is NULL

...

further arguments

Details

The function waldtest.ciregic returns a result of Wald test.

Value

The function waldtest returns an output table of Wald test of the model from object.

varnames.full

a variable name of a vector of variables names in the full model

varnames.nested

a variable name of a vector of variables names in the nested model

vcov

the estimated bootstrap variance-covariance matrix for overall Wald test

vcov.event1

the estimated bootstrap variance-covariance matrix for cause-specific Wald test (event type 1)

vcov.event2

the estimated bootstrap variance-covariance matrix for cause-specific Wald test (event type 2)

table

a table including test statistic, degrees of freedom, and p-value

Author(s)

Jun Park, [email protected]

Giorgos Bakoyannis, [email protected]

See Also

The fitted semiparametric regression on cumulative incidence function with interval-censored competing risks data ciregic and left-truncated and interval-censored competing risks data ciregic_lt

Examples

## Continuing the ciregic(...) example
library(intccr)
waldtest(obj1 = fit)
set.seed(12345)
newdata <- dataprep(data = longdata, ID = id, time = t,
                    event = c, Z = c(z1, z2))
fit.nested <- ciregic(formula = Surv2(v = v, u = u, event = c) ~ z2, data = newdata,
                      alpha = c(1, 1), nboot = 0, do.par = FALSE)
waldtest(obj1 = fit, obj2 = fit.nested)