It is sometimes helpful to look back at recent history in order to see just how far we have come in terms of progress in medicine, wealth, and health. Ours is an era of rapid, profound change in technology and its capabilities, and that is very apparent in mortality statistics, such as the charts provided in the article noted here. The numbers change dramatically every few decades, the result of the scientific and medical communities turning their attention to the most pressing issues of their time, generation after generation.
The past century is a story of success due to advancing medical technology on the one hand and the will, wealth, and understanding to address environmental causes of mortality on the other. Yet at the same time improvements in wealth, comfort, and longevity created new forms of bad lifestyle choice and new challenges in health. Over the course of the 20th century, infectious diseases gave way to lifestyle diseases and age-related diseases. As ever more people had the opportunity to live longer, the medical conditions of old age increased as a cause of mortality - and then the medical community turned to address those newly prominent causes of death. Some lines on the chart of mortality fell and others rose. A line may rise for decades until it reaches the point of perceived crisis, then it falls as greater efforts are made to prevent and treat the conditions responsible.
One of the goals of treating aging as a medical condition is to break this cycle - to have no more rising lines for age-related disease on the chart of causes of mortality. If the medical community tries to control diseases of old age one by one, firstly they will fail to reduce the incidence to zero because the only way to prevent age-related disease is to address the root causes of aging, and secondly partial and limited success in controlling age-related conditions, already achieved for heart disease, just means another condition will cause aged, damaged patients to die. One line on the chart falls, another rises to take its place. The way out is to repair the root causes of aging, the biochemical damage that produces age-related dysfunction and disease. To the degree that this damage is repaired successfully, the incidence of all age-related disease will fall.
From the beginning of the 20th century to 2010, the life expectancy at birth for females in the United States increased by more than 32 years. However, new causes of death have emerged with changes in technology and the built environment (eg, the automobile and highways), emerging infections (eg, HIV), and behavior (eg, cigarette smoking). We analyzed trends in mortality rates among females at each decade from 1900 through 2010, focusing on major causes of death, and examined differences by age and by race. Historical trends may indicate future trends, contributing factors, opportunities for intervention when interventions are known, and research needs when they are not.
We analyzed all-cause unadjusted death rates (UDRs) for males and females and for white and nonwhite males and females from 1900 through 2010 in decadal years to indicate mortality burden. We analyzed UDRs for black persons beginning in 1970 when the data were first made available. We also computed age-adjusted all-cause death rates (AADRs) by the direct method using age-specific death rates and the 2000 US standard population.
From 1900 to 2010, the UDR among females in the United States decreased from 1,646.9 per 100,000 to 787.4 per 100,000, an overall decrease of 52.2%. Among males, the UDR decreased from 1,791.1 per 100,000 in 1900 to 812.0 per 100,000 in 2010, an overall decrease of 54.7%. The male UDR exceeded the female UDR in all decadal years except 2000; by 2010, the male excess had decreased to 24.6. From 1970 to 2010, death rates increased by 5.5% among white females and decreased by 22.5% among black females. Rates decreased by 20.3% among white males and by 38.9% among black males.
From 1900 to 2010, the AADR among females decreased from 2,410.4 per 100,000 to 634.9 per 100,000, a decrease of 73.7%. Among males, the AADR decreased from 2,630.8 per 100,000 in 1900 to 887.1 per 100,000 in 2010, a decrease of 66.3%. The male AADR exceeded the female AADR in all decades, with the greatest excess in 1970 at 570.7 per 100,000; the male excess was higher in 2010 than in 1900.
The 5 major causes of death for females in 1900 (46.3% of all deaths) were pneumonia and influenza (198.5 per 100,000), tuberculosis (187.8 per 100,000), enteritis and diarrhea (134.9 per 100,000), heart disease (133.7 per 100,000), and stroke (107.7 per 100,000). Of these causes, only heart disease and stroke were among the 5 major causes in 2010. In 2010, the 5 major causes (59.7% of all deaths) were heart disease (184.9 per 100,000), all cancers (168.2 per 100,000), stroke (49.1 per 100,000), chronic lower respiratory diseases (46.3 per 100,000), and motor vehicle accident (21.8 per 100,000).
Twenty years of the 30-year increase in female life expectancy from 1900 to 2010 occurred between 1900 and 1950, affected principally by social and environmental factors. During the first half of the 20th century, sanitation improved substantially, with greater benefits for blacks than for whites. Sanitation, the provision of clean drinking water and safe disposal of sewage and solid waste, affected rates of infectious and chronic diseases and was associated with almost half the total decrease in mortality rates in major US cities between 1900 and 1940, three-quarters of the decrease in infant mortality rates, and almost two-thirds of the decrease in child mortality rates.
Three major nonexclusive explanations for increased heart disease mortality rates from 1900 to 1950 are possible. First, as understanding of diseases improved, the apparent rise may have partly resulted from changes in classifying and assigning causes of death during the first half of the century. Second, the rise has also been attributed to a reduction in "competing causes" of death, most notably the reduction of deaths due to infectious and diarrheal diseases. Third, cigarette smoking was a major influence on trends in female chronic disease mortality rates. The prevalence of cigarette smoking among females rose rapidly in the 1930s, peaked from about 1965 to 1975, and decreased thereafter.
Much of the decrease in mortality rates among females in the past 110 years is attributable to improvements in major social and environmental determinants of health - education, income, housing, and sanitation. The rapid decrease in mortality rates from infectious by mid-century largely preceded the widespread use of antibiotics or immunization. The extent and specific causes of increased heart disease mortality rates among females in the first half of the century remain uncertain. The decrease of heart disease mortality rates during the second half of the century may be the result of multiple factors.
Trends in mortality rates during the past century reflect major patterns of health determinants. Sanitary and safety improvements along with understanding of and therapies for infectious diseases led to great reductions in infectious causes of death. With increasing longevity and more sedentary lifestyles, chronic diseases increased as major causes of death. Although some of these causes, particularly heart disease and stroke, decreased as a result of behavior change and effective health care, decreases in mortality rates are slowing.