Est2Replicates {ipwErrorY}

Estimation of ATE with Two Replicates

Description

Estimation of average treatment effect when misclassification probabilities are unknown but two independent replicates of the outcome are available

Usage

Est2Replicates(data, indA, indYerror, indX,
  constraint = c("sensitivity equals specificity", "known sensitivity",
  "known specificity", "known prevalence"), sensitivity = NULL,
  specificity = NULL, prevalence = NULL, confidence = 0.95)

Arguments

data

The dataset to be analyzed in the form of R data frame without missing data

indA

A column name indicating the binary treatment variable

indYerror

A vector of two column names indicating replicates of the binary outcome variable

indX

A vector of column names indicating the covariates included in the treatment model

constraint

The constraint to be used; the default assumes sensitivity equals specificity

sensitivity

The specified sensitivity between 0 and 1 when imposing the constraint that sensitivity is known, and the default is set to be NULL

specificity

The specified specificity between 0 and 1 when imposing the constraint that specificity is known, and the default is set to be NULL

prevalence

The specified prevalence between 0 and 1 when imposing the constraint that prevalence is known, and the default is set to be NULL

confidence

The confidence level between 0 and 1; the default is 0.95 corresponding to a 95 per cent confidence interval

Value

A list of the estimate of average treatment effect, sandwich-variance-based standard error, confidence interval, imposed constraint, and the information on sensitivity and specificity

Examples

#create a dataset with sensitivity=0.95 and specificity=0.85
set.seed(100)
X1=rnorm(2000)   
A=rbinom(2000,1,1/(1+exp(-0.2-X1)))
Y=rbinom(2000,1,1/(1+exp(-0.2-A-X1)))
y1=which(Y==1)
y0=which(Y==0) 
Yast1=Y
Yast1[y1]=rbinom(length(y1),1,0.95)
Yast1[y0]=rbinom(length(y0),1,0.15)
Yast2=Y
Yast2[y1]=rbinom(length(y1),1,0.95)  
Yast2[y0]=rbinom(length(y0),1,0.15)
da=data.frame(A=A,X1=X1,Yast1=Yast1,Yast2=Yast2)
head(da)
#apply the correction method assuming specificity=0.85
Est2Replicates(da,"A",c("Yast1","Yast2"),"X1","known specificity",NULL,0.85,NULL,0.95)