Estimation in Semiparametric Transition Measurement Error Models for Longitudinal Data,’’ Biometrics., forthcoming in

We consider semiparametric transition measurement error models for longitudinal data, where one covariate is measured with error and no distributional assumption is made for the underlying unob-served covariate. An estimating equation approach based on the pseudo conditional score method is proposed. We show the resulting estimators of the regression coecients are consistent and asymp-totic normal. We derive the semiparametric eciency score and study the eciency loss of the pseudo conditional score estimator. In the presence of validation data, we propose a one-step estimator that achieves the semiparametric ecient bound. Simulation studies are conducted to examine the small-sample performance of our estimator. A real data set is analyzed for illustration