ATOPobs {experiment}

Sensitivity analysis for the ATOP when some of the Outcome Data are Missing Under the Matched-Pairs Design in Observational Studies

Description

This function computes the bounds on the average treatment effect among always-observed pairs (ATOP) with pre-specified sensivity parameters when some of the outcome data are missing. The sensivity parameters characterizes the degree of the within-pair similarity and the dependence between the potential missing indicators and the treatment. The confidence intervals for the ATOP are also computed.

Usage

ATOPobs(Ya, Yb, Ra, Rb, Ta, Tb, gamma, kappa1, kappa0, l, u, alpha, rep)

Arguments

Ya

A vector of the outcomes of the first unit in the matched pairs. The missing values for Ya should be coded as NA.

Yb

A vector of the outcomes of the second unit in the matched pairs. The missing values for Yb should be coded as NA.

Ra

A vector of the missing data indicators of the first unit in the matched pairs.

Rb

A vector of the missing data indicators of the second unit in the matched pairs.

Ta

A vector of the treatment conditions of the first unit in the matched pairs.

Tb

A vector of the treatment conditions of the second unit in the matched pairs.

gamma

The sensitivity parameter which charaterizes the degree of the within-pair similarity.

kappa1

The sensitivity parameter which charaterizes the dependence between R(1) and T.

kappa0

The sensitivity parameter which charaterizes the dependence between R(0) and T.

l

The lower limit of the outcome.

u

The upper limit of the outcome.

alpha

A positive scalar that is less than or equal to 0.5. This will determine the (1-alpha) level of confidence intervals. The default is 0.05.

rep

The number of repetitions for bootstraping.

Details

For the details of the method implemented by this function, see the references.

Value

A list of class ATOPsens which contains the following items:

LB

The lower bound for the ATOP.

UB

The upper bound for the ATOP.

LB.CI

The lower limit of the confidence interval for the ATOP.

UB.CI

The upper limit of the confidence interval for the ATOP.

Author(s)

Kosuke Imai, Department of Government and Department of Statistics, Harvard University [e-mail], https://imai.fas.harvard.edu; Zhichao Jiang, Department of Politics, Princeton University [e-mail].

References

Kosuke Imai and Zhichao Jiang (2018). “A Sensitivity Analysis for Missing Outcomes Due to Truncation-by-Death under the Matched-Pairs Design”, Statistics in Medicine.

Examples

data(seguro)
attach(seguro)
ATOPsens(Ya,Yb,Ra,Rb,Ta,Tb,gamma=0.95,l=0,u=1,alpha=0.05,rep=100)