In the 1960s and 1970s, physicians and medical educators began to recognize a basic flaw in the health care system. Medicine traditionally was concerned with treating disease after symptoms appeared, resulting in treatment that was often very expensive. About 600,000 coronary bypass operations were performed annually in the United States in the 1990s, at a cost of $44,000 each. Medical officials recognized the advantage of preventing disease in the first place, rather than just treating it.

Medical schools began teaching students the importance of disease prevention. Some physicians specialized in a new field, preventive medicine, which emphasized keeping patients healthy. Practicing physicians spent more time counseling patients about smoking, excessive drinking, and other unhealthy practices. They did so by encouraging patients to avoid risk factors for disease; take periodic screening tests that detect disease early; and treat high blood pressure.

Yet by the late 1990s, many people still failed to use preventive services. Studies in 1997 estimated that 30,000 deaths per year could have been prevented if more people were immunized against influenza, pneumococcal pneumonia, and hepatitis B. Likewise, smoking, the leading preventable cause of death in the industrialized world, causes more than 4 million deaths worldwide each year.

Another dramatic change in medicine involved the idea that individuals have an important role in preventing diseases caused by an unhealthy lifestyle. Health care consumers grew more knowledgeable about medicine. Medical pages became a regular feature of major newspapers, news magazines, and television news programs. Some people subscribed to magazines and newsletters devoted entirely to health. Laypeople consulted books, such as the Physician's Desk Reference and The Merck Manual, once used only by professionals. They also tapped health information available on the Internet's World Wide Web (WWW). With this knowledge, consumers sought to become partners with their physicians in deciding the best ways of preventing, diagnosing, and treating disease.