A preventive medicine specialist focuses on the health of individuals and defined populations in order to protect, promote, and maintain health and well-being, and to prevent disease, disability, and pre-mature death. The distinctive components of preventive medicine include: 1) Biostatistics and the application of biostatistical principles and methodology; 2) Epidemiology and its application to population-based medicine and research; 3) Health services management and administration including: developing, assessing, and assuring health policies; planning, implementing, directing, budgeting, and evaluating population health and disease management programs; and utilizing legislative and regulatory processes to enhance health; 4) Control of environmental factors that may adversely affect health; 5) Control and prevention of occupational factors that may adversely affect health safety; 6) Clinical preventive medicine activities, including measures to promote health and prevent the occurrence, progression, and disabling effects of disease and injury; and 7) Assessment of social, cultural, and behavioral influences on health. Practitioners work in many settings, including the armed forces, general and family practice, government, international health agencies, hospitals, health centers, health maintenance organizations, and industry. They are heavily involved in influencing public policy, public health, and designing health care systems to prevent and control the spread of diseases. A preventive medicine physician may be a specialist in general preventive medicine, public health, occupational medicine, or aerospace medicine. This specialist works with large population groups as well as with individual patients to promote health and understand the risks of disease, injury, disability, and death, seeking to modify and eliminate these risks.