Life Expectancy – a statistical calculation representing how many years a person might expect to live. Simple life expectancy calculates projected years of life from birth. Age-adjusted life expectancy projects how many more years a person of a certain age might expect to live. It is important to remember that such calculations are projections, not factual assertions of how long an individual will live. Any individual may live longer or less than his or her life expectancy as a result of numerous variables.
Life expectancy at birth has steadily increased in the United States, climbing by 60 percent overall between 1900 and 2000. A child born in 1900 could expect to live about 48 years, whereas a child born in 2000 could expect to live about 77 years. Though life expectancy for men remains less than that for women, the gap is slowly closing. Some health experts believe discoveries in genetics and molecular medicine in the early years of the 21st century have the potential to extend life expectancy 15 to 25 percent within the next decade.
Increases in life expectancy have historically reflected improvements in numerous areas of public health, ranging from sanitation to vaccinations. Current increases reflect health and healthcare improvements primarily in areas such as pharmaceuticals, diagnostic procedures that allow early detection of potentially fatal health conditions, and therapeutic technologies. Individual variables such as family and PERSONAL HEALTH HISTORY also influence life expectancy, as do behaviors that affect health such as cigarette smoking. Numerous government agencies publish life expectancy data, updated annually.
See also HEALTH RISK FACTORS; LIFESTYLE AND HEALTH; IMMUNIZATION; YOUTH HIGH-RISK BEHAVIORS.