Recurrent events are frequently encountered in biomedical studies. Evaluating the covariates effects on the marginal recurrent
event rate is of practical interest. There are mainly two types of rate models for the recurrent event data: the multiplicative
rates model and the additive rates model. We consider a more flexible additive–multiplicative rates model for analysis of
recurrent event data, wherein some covariate effects are additive while others are multiplicative. We formulate estimating
equations for estimating the regression parameters. The estimators for these regression parameters are shown to be consistent
and asymptotically normally distributed under appropriate regularity conditions. Moreover, the estimator of the baseline mean
function is proposed and its large sample properties are investigated. We also conduct simulation studies to evaluate the
finite sample behavior of the proposed estimators. A medical study of patients with cystic fibrosis suffered from recurrent
pulmonary exacerbations is provided for illustration of the proposed method.
Keywords Recurrent events - Rate regression - Additive–multiplicative rates model - Counting process - Empirical process