Pulmonary embolism becomes an increasingly important problem as the extent of its incidence becomes unveiled. Although the subject of much study, the incidence of pulmonary embolism has remained a matter of uncertainty and disagreement. Pulmonary embolism is reported by some as being infrequent; it may, in fact, represent one of the most important forms of terminal illness, one of the commonest causes of death in the population at large. The diagnosis of pulmonary embolism is difficult and equivocal. The disease is usually portrayed as being of sporadic occurrence; although this conception is deeply rooted in medical opinion, it is open to question. To obtain an exact measure of the incidence of fatal pulmonary embolism in the general population, two conditions must be fulfilled: the evaluation must be based on autopsy examinations and a high percentage of the deaths in a given community over a period of years must be examined The disagreement in the literature regarding the incidence of pulmonary embolism stems from the fact that it has been difficult to provide circumstances in which these conditions could be fulfilled.
POSSIBLE APPROACHES TO PROBLEMSStudies of pulmonary embolism in the past, despite the variable factors encountered and despite the difficulties in obtaining comprehensive data, have contributed im¬ portant information. The incidence of pulmonary embo¬ lism continues to be studied intensely in many clinics. In previous surveys of thromboembolic disease of the lung, recourse has generally been had to three avenues of investigation: vital statistics, clinical studies of cases diagnosed in the hospital, and general hospital autopsy studies. These methods, because of their inherent limita¬ tions, do not provide conclusive cross-sectional data of the incidence of pulmonary embolism in the general popu¬ lation. In pursuit of this problem, a fourth method, the autopsy study of persons in custodial institutions, is of¬ fered in the present work.Vital Statistics.-Vital statistics, as generally regis¬ tered, are unacceptable as an indicator of the incidence of pulmonary embolism because of inevitable errors in deathbed diagnosis and inadequate number of autopsies. Members of the older age group, in large proportion, re¬ main at home during their terminal illness; at death, which is often ascribed to "natural causes," autopsy is not performed. Definite information regarding the na¬ ture and incidence of terminal illness is buried with the remains and lost forever. A survey of vital statistics shows that the diagnosis of pulmonary embolism is rarely made by physicians in deaths occurring at home. In the vital statistics of the city of Columbus, Ohio, in 1951, 3,958 deaths representing all ages were registered; of these deaths, slightly over one-half, 2,133, occurred in hospitals. Pulmonary embolism was diagnosed in 62 cases, or 2.91% of hospital deaths. In deaths that oc¬ curred at home, the diagnosis was considered in 0.76% of cases; these vital statistics indicate that the diagnosis of pulmonary embolism w...
