Key points are not available for this paper at this time.
Gary M. Marsh, B. Raja Rao, Mary Preininger, Jeffrey Ehland, Harvey T. CoChien, OCMAP (Module 6): Extended Proportional Mortality Analysis with Simultaneous Inferential Procedures, The American Statistician, Vol. 43, No. 2 (May, 1989), pp. 127-128
Marsh et al. (1989) studied this question.