A standardized ratio for measuring the “suddenness” of events with applications to the four leading causes of violent death and to certain birth defects

Abstract

An index which provides a measure of abrupt or sudden change in epidemic trends is provided. Using this index, a simple comparison of the epidemiology of deaths due to homicides, suicides, motor vehicle accidents, and other accidents is made. One example of the findings is that the trend in accidental deaths over recent years possesses more spontaneity or temporal clustering than the trend in violent nonaccidental deaths. Another application reveals an informative epide‐miologic feature of the birth defects tracheoesophageal fistula and esophageal atresia. Implications of such findings are considered.