Prevention is better than cure.

—Desiderius Erasmus

Preventing disease involves a wide range of interrelated programs, actions, and activities. Some prevention measures are sweeping global policy initiatives, such as national and state government actions to reduce health risks by limiting air pollution and other toxic exposures or standards to assure the safety of food and water supplies. Others are focused efforts of public health professionals and agencies, such as the National Institutes of Health (NIH) Office of Disease Prevention, Centers for Disease Control and Prevention (CDC), and the American Cancer Society, to reduce the incidence (occurrence of new cases) of specific diseases such as heart disease, diabetes, and lung cancer.

The effectiveness of global and local disease prevention programs largely depends on the extent to which individuals take personal responsibility for their own health by avoiding health risks such as tobacco use, substance abuse...