Deb and Trivedi (1997) analyze data on 4406 individuals, aged 66 and over, who are covered by Medicare, a public insurance program. Originally obtained from the US National Medical Expenditure Survey (NMES) for 1987/88, the data are available from the data archive of the Journal of Applied Econometrics. It was prepared for an R package accompanying Kleiber and Zeileis (2008) and is also available asDebTrivedi.rda in the Journal of Statistical Software together with Zeileis (2006). The objective is to model the demand for medical care -as captured by the number of physician/non-physician office and hospital outpatient visits- by the covariates available for the patients.
Zeileis, A. and Kleiber, C. and Jackma, S. (2008). "Regression Models for Count Data in R". JSS 27, 8, 1–25.