Medical care gets too much credit for prolonging life.
A 2002 Health Affairs journal article calculated the contribution of factors that determined health and premature death. Those influences were personal behavior, life circumstances, environmental toxins, medical care and genes.
Behavior accounts for 40 percent of premature deaths. The leading causes in this category are smoking, obesity and physical inactivity. While Americans place great faith in medical technology to extend life, simple changes in health habits would have far more impact.
Life circumstances cause 15 percent of premature death, but may contribute significantly to the other factors. People with lower income, less education and lower social status die sooner and are more likely to be disabled. People in lower classes are more likely to have poor health behavior: They smoke more, and have riskier lifestyles.
Environmental exposures account for 5 percent of premature deaths. Occupational products, pollution, lead paint and chemical contaminants are unpleasant facts in dangerous jobs and substandard living conditions.
Medical care affects only 10 percent of premature deaths, yet it accounts for 95 percent of U.S. health-care spending. The big contributors in this category are lack of access and medical errors, which the Institute of Medicine estimates kill as many as 98,000 people annually. Lack of health insurance, which affects 16 percent of the U.S. population, also contributes to premature death.
Genes, which are considered an uncontrollable factor, cause 30 percent of premature deaths. Yet genetic predisposition is not destiny. About two-thirds of obesity risk is genetic, but the condition does not happen without poor health habits. Dr. David Heber, director of the UCLA Center for Human Nutrition, points out that the human DNA changes 0.5 percent every million years but the obesity epidemic is only about 30 years old.