On a repeated-measurement model with errors in dependent variable

The model in this paper is motivated by a study of the effectiveness of pulsed electromagnetic field energy on healing of wounds, in which the wound sizes z_ijr at time t for subject j under treatment i were observed with error. The healed wound size y_ijt, defined by z_ij,t-1-z_ijt, is modeled as the dependent variable in a repeated-measurement model. Two classical measurement error models relating the observed proxy wound size z*_ijt and the true wound size z_ijt are considered: additive and multiplicative measurement error models. In this paper, we propose estimates of variance parameters, including the variance of the measurement error, via the method of moments when the dependent variable y_ijt is erroneously measured due to the measurement error in z_ijt. The proposed estimates of variance parameters are shown to be consistent and perform well in the simulation.