partdevs {sensmediation}

Implementations of the partial derivatives (gradients) of the expressions for the direct, indirect and total effects. Used to calculate standard errors (delta method).

Description

Functions implementing the partial derivatives (gradients) of the expressions for the direct, indirect and total effects. These are then used to calculate standard errors of the effects using the delta method. Called by the stderrs functions. The functions are named according to the convention partdevs."mediator model type""outcome model type" where bstands for binary probit regression and c stands for linear regression.

Usage

partdevs.bb(beta0, beta1, beta2, beta3, theta0, theta1, theta2, theta3,
  theta4, theta5, theta6, theta7, x.med, x.out, t.de, t.ie, exp.value,
  control.value)

partdevs.bc(beta0, beta1, beta2, beta3, theta2, theta3, theta6, theta7,
  x.med, x.out, t.de, t.ie, exp.value, control.value)

partdevs.cb(beta0, beta1, beta2, beta3, theta0, theta1, theta2, theta3,
  theta4, theta5, theta6, theta7, sigma.eta, x.med, x.out, t.de, t.ie,
  exp.value, control.value)

partdevs.cc(beta0, beta1, beta2, beta3, theta2, theta3, theta6, theta7,
  exp.value, control.value, x.med, x.out, t.de, t.ie)

Arguments

beta0, beta1

Vectors of mediator regression parameters (intercept and exposure) over Rho

beta2, beta3

Matrices of mediator regression parameters (covariate main effects and exposure-covariate interactions) over Rho

theta0, theta1, theta2, theta3

Vectors of outcome regression parameters (intercept, exposure, mediator, exposure-mediator interaction) over Rho

theta4, theta5, theta6, theta7

Matrices of outcome regression parameters (covariate main effects, exposure-covariate, mediator-covariate and exposure-mediator-covariate interactions) over Rho

x.med

Mediator covariate matrix for which to calculate standard errors

x.out

Outcome covariate matrix for which to calculate standard errors

t.de, t.ie

exposure values used to calculate the direct and indirect effects depending on the desired decomposition (see the Details section of sensmediation for more information). If alt.decomposition = TRUE then t.de = exp.value and t.ie = control.value, otherwise t.de = control.value and t.ie = exp.value.

exp.value

value of the exposure variable used as the exposure condition.

control.value

value of the exposure variable used as the control (unexposed) condition.

sigma.eta

For a continuous mediator and binary outcome, matrix with the estimated residual standard deviation for the mediator model over the range of Rho.