Key points are not available for this paper at this time.
Paul M. Densen, Sam Shapiro, Marilyn Einhorn, Concerning High and Low Utilizers of Service in a Medical Care Plan, and the Persistence of Utilization Levels over a Three Year Period, The Milbank Memorial Fund Quarterly, Vol. 37, No. 3 (Jul., 1959), pp. 217-250
Densen et al. (Wed,) studied this question.