The relation of morbidity to age in an army population.

Abstract

Public health statistics provide a wealth of material with reference to the relation of age to mortality risk from individual diseases; and it has long been customary to adjust mortality rates by means of appropriate standardizing factors to forestall erroneous comparisons of crude deaths in populations of different age structure. Within the framework of private practice, civilian medicine provides no comparable opportunities for an exact study of the relation of age to risk of contracting diseases, other than such as are certifiable to public health authorities or such as are speedily fatal. Indeed current medical treatises and articles abound with figures for proportions of cases examined in different age groups cited as an indication of the liability of individuals to contract a particular disease in a given age group. It should be but is not in fact needless to remark that this procedure is highly misleading. Naturally, the physician meets very few cases of peptic ulcer among males between the ages of 95 and 99 inclusive, for the simple reason that there are in fact very few males alive at that age. The practice of putting on record such case-age distributions, in contradistinction to age-incidence distributions exhibiting frequency of onset related to the appropriate population at risk at a given time of life, is a counsel of despair consequent upon the difficulty of delimiting the population from which a civil hospital draws its patients, and hence of defining the relevant demographic data for drawing correct conclusions. Correct information of this sort is of value both because it may furnish clues for an attack on the nature of the ageing process, and because it is a prerequisite of medical man-power planning in a society with a swiftly-changing age-composition. The Army, with an all-in system of social medicine and a complete population census, therefore offers a unique opportunity for studying the relation of age to