imcid {MCID} | R Documentation |
Point and interval estimation for the MCID at the individual level
Description
We formulate the individualized MCID as a linear function of the patients' clinical profiles. imcid
returns the point estimate for the linear coefficients of the MCID at the individual level
Usage
imcid(x, y, z, n, lambda, delta, maxit = 100, tol = 0.01, alpha = 0.05)
Arguments
x |
a continuous variable denoting the outcome change of interest |
y |
a binary variable indicating the patient-reported outcome derived from the anchor question |
z |
a vector or matrix denoting the patient's clinical profiles |
n |
the sample size |
lambda |
the selected tuning parameter |
delta |
the selected tuning parameter |
maxit |
the maximum number of iterations. Defaults to 100 |
tol |
the convergence tolerance. Defaults to 0.01 |
alpha |
nominal level of the confidence interval. Defaults to 0.05 |
Value
a list including the point estimates for the linear coefficients of the individualized MCID and their standard errors, and the corresponding confidence intervals based on the asymptotic normality
Examples
n <- 500
lambdaseq <- 10 ^ seq(-3, 3, 0.1)
deltaseq <- seq(0.1, 0.3, 0.1)
a <- 0.1
b <- 0.55
c <- -0.1
d <- 0.45
### True linear coefficients of the individualized MCID: ###
### beta0=0, beta1=0.5 ###
set.seed(115)
p <- 0.5
y <- 2 * rbinom(n, 1, p) - 1
z <- rnorm(n, 1, 0.1)
y_1 <- which(y == 1)
y_0 <- which(y == -1)
x <- c()
x[y_1] <- a + z[y_1] * b + rnorm(length(y_1), 0, 0.1)
x[y_0] <- c + z[y_0] * d + rnorm(length(y_0), 0, 0.1)
sel <- cv.imcid(x = x, y = y, z = z, lamseq = lambdaseq,
delseq = deltaseq, k = 5, maxit = 100, tol = 1e-02)
lamsel <- sel$'Selected lambda'
delsel <- sel$'Selected delta'
result <- imcid(x = x, y = y, z = z, n = n, lambda = lamsel,
delta = delsel, maxit = 100, tol = 1e-02, alpha = 0.05)
result$'Point estimates'
result$'Standard errors'
result$'Confidence intervals'