Reduced Variation in Death Rates after Introduction of Antimicrobial Agents

Abstract

There was a sharp, persistent drop in annual variation in life expectancy at birth in the United States between 1940 and 1950. To evaluate the possible relationship of this drop to the introduction of antimicrobial agents, we examined standardized death rates (SDR) and life expectancy (LE) in the United States and in England and Wales, both of which participated in the discovery and development of antimicrobials, especially penicillin, during this period. Annual variation in life expectancy and directly standardized death rates are measured as residuals from moving means. There were sharp drops in residual variation for males and females starting as early as 1944 in the United States and 1951 in England and Wales that persist to the present. The standard deviations of residuals dropped by 59–81% from before 1940 to after 1950 depending on sex, country, and SDR or LE. The timing and persistence of reduced annual variation indicates that antimicrobials contributed substantially to the change.