R: Causal risk ratio of a binary or continuous endogenous...
RR
R Documentation
Causal risk ratio of a binary or continuous endogenous variable
Description
RR can be used to calculate the causal risk ratio of a binary or continuous endogenous predictor/treatment, with
corresponding interval obtained using posterior simulation.
Usage
RR(x, nm.end, E = TRUE, treat = TRUE, type = "bivariate", ind = NULL,
n.sim = 100, prob.lev = 0.05, length.out = NULL, hd.plot = FALSE,
rr.plot = FALSE,
main = "Histogram and Kernel Density of Simulated Risk Ratios",
xlab = "Simulated Risk Ratios", ...)
Arguments
x
A fitted SemiParBIVProbit object as produced by SemiParBIVProbit().
nm.end
Name of the endogenous variable.
E
If TRUE then RR calculates the sample RR. If FALSE then it calculates the sample RR
for the treated individuals only.
treat
If TRUE then RR calculates the RR using the treated only. If FALSE then it calculates the ratio using
the control group. This only makes sense if E = FALSE.
type
This argument can take three values: "naive" (the effect is calculated ignoring the presence of observed and unobserved confounders), "univariate" (the effect is obtained from the univariate probit model which neglects the presence of unobserved confounders) and "bivariate" (the effect is obtained from the bivariate model which accounts for observed and unobserved confounders).
ind
Binary logical variable. It can be used to calculate the RR for a subset of the data. Note that it does not make sense to use ind
when some observations are excluded from the RR calculation (e.g., when using E = FALSE).
n.sim
Number of simulated coefficient vectors from the posterior distribution of the estimated model parameters. This is used
when delta = FALSE. It may be increased if more precision is required.
prob.lev
Overall probability of the left and right tails of the RR distribution used for interval calculations.
length.out
Ddesired length of the sequence to be used when calculating the effect that a continuous
treatment has on a binary outcome.
hd.plot
If TRUE then a plot of the histogram and kernel density estimate of the simulated risk ratios is produced. This can
only be produced when binary responses are used.
rr.plot
For the case of continuous endogenous variable and binary outcome, if TRUE then a plot (on the log scale)
showing the risk ratios that the binary outcome is equal to 1 for each incremental value of the endogenous variable
and respective intervals is produced.
main
Title for the plot.
xlab
Title for the x axis.
...
Other graphics parameters to pass on to plotting commands. These are used only when hd.plot = TRUE.
Details
RR calculates the causal risk ratio of the probabilities of positive outcome under
treatment (the binary predictor or treatment assumes value 1) and under
control (the binary treatment assumes value 0). Posterior simulation is used to obtain a
confidence/credible interval.
RR works also for the case of continuous endogenous treatment variable.
Value
res
It returns three values: lower confidence interval limit, estimated RR and upper interval limit.
prob.lev
Probability level used.
sim.RR
It returns a vector containing simulated values of the average RR. This
is used to calculate intervals.
Ratios
For the case of continuous endogenous variable and binary outcome, it returns a matrix made up of
three columns containing the risk ratios for each incremental value in the endogenous variable and respective intervals.