Estimação robusta para o modelo de tempo de vida acelerado Birnbaum-Saunders.

Abstract

The robust estimation method is an important tool to limit the influence of outliers on both the response variable and the covariates of an accelerated life model. In this work we used the Birnbaum-Saunders distribution, which has been extensively applied in survival analysis studies. We presented the log-linear form of the accelerated life model, we performed the robust estimation and approximated the variances of the robust estimators by a function of variance and covariance of the sandwich type. In addition, using different scenarios, we performed simulation studies to evaluate the performance of the proposed robust estimator. Finally, we present two applications in real data sets that illustrate the methodology presented.