O. Wu, Colin et al., A shared parameter model for the estimation of longitudinal concomitant intervention effects, Biostatistics (Oxford. Print) , 12(4), 2011, pp. 737-749
We investigate a change-point approach for modeling and estimating the regression effects caused by a concomitant intervention in a longitudinal study.Since a concomitant intervention is often introduced when a patient's health status exhibits undesirable trends, statistical models without properly incorporating the intervention and its starting time may lead to biased estimates of the intervention effects.We propose a shared parameter change-point model to evaluate the pre- and postintervention time trends of the response and develop a likelihood-based method for estimating the intervention effects and other parameters.Application and statistical properties of our method are demonstrated through a longitudinal clinical trial in depression and heart disease and a simulation study.