Description: Article from The Actuary, April 1972 – volume 6 - Issue 4 is a review of a book by Lewis C. Robbins, M.D., M.P.H. and Jack H. Hall, A.B., M.D., titled How To Practice Prospective Medicine by assessing and classifying various health risk factors. The review states the authors' basic assumption that average risk can be determined by calculating the total numbers of deaths by cause in the general population is open to criticism. Furthermore, the assignment of weights for the individual risk factors is quite tenuous in many instances. The authors acknowledge this, but once a number appears in print, especially as part of a complex table, it achieves a sanctity that is difficult to destroy.