US Demographics

Geriatric Essentials

• Until recently, the growth rate of the population >= 65 yr exceeded that of the total population.
• Although the growth rate of the population >= 65 yr has slowed, it is expected to exceed the growth rate of the total population again when baby boomers begin reaching age 65 in 2011.
• Geographic distribution of elderly people in the US varies greatly.
• In the US, the growing percentage of elderly people will have enormous effects on the distribution and cost of health care.
• Life expectancy at age 65 continues to increase and is now > 18 yr.

Population Characteristics

Between 1900 and 2000, the total US population increased 3-fold, but the population of people >= 65 yr increased > 10-fold. Near the end of this period between 1990 and 2000, there was a 13.2% increase in size of the total population but only a 12% increase in size of the >= 65 population. This led to a reduction in the percentage of those >= 65 from 12.6% in 1990 to 12.4% in 2000. Nonetheless, the growth rate for the population >= 65 yr is expected to outpace that for the total population during the next several decades, especially when baby boomers begin to reach 65 in 2011. By 2040, the percentage of those >= 65 is projected to increase to about 20%. In 2000, the number of people in the US >= 65 was nearly 35 million (see Table 2-1); this number is estimated to reach 55 million by 2020 and 80 million by 2040.

One of the fastest-growing segments of the population, the oldest old (people >= 85), accounted for about 12% of all elderly people in 2000 and is projected to account for 19% by 2040. Between 1940 and 2040, the >= 65 population is projected to increase 9-fold and the >= 85 population will increase 40-fold. The number of centenarians is increasing faster and is projected to increase from 50,000 in 2000 to about 550,000 in 2040. Per capita costs for acute and long-term health care services are highest for people >= 85, so the growth of this population segment markedly affects health care costs.

In the US, the elderly population, like the total population, is more racially diverse than in the past. Between 1980 and 2000, the elderly population increased by 26% among whites, 35% among blacks, 173% among Hispanics, and 274% among Asians. In 2000, 16.5% of the elderly population was nonwhite or Hispanic; this percentage is expected to increase to about 31% by 2040.

In the 2nd half of the 20th century, the mortality rate for elderly women declined more rapidly than that for elderly men. Among people >= 65 in 1950, there were 89 men for every 100 women. In 2000, there were 70 men for every 100 women; among people >= 85, there were 41 men for every 100 women.

In 2000, 75% of elderly men were married, compared with only 43% of elderly women. Rate of widowhoodvaries by age, sex, and race. In 2000, 55% of women aged 75 to 84 were widowed. Of people >= 85, black women had the highest rate of widowhood (82%); white men had the lowest (31%).

Among community-dwelling people >= 65, living arrangements vary greatly by age and sex. In 2002, 72% of elderly men lived with their spouse, compared with only 41% of elderly women; 40% of elderly women lived alone, compared with only 19% of elderly men. At ages 65 to 74, about 1/3 of women live alone; after age 75, nearly 50% of women live alone. Before age 85, the elderly seldom live with nonrelatives or with relatives other than a spouse; after age 85, 11% of men and 29% of women who live in the community do so (see Figure 2-1).

As the percentage of elderly to younger people increases, less financial and social support will be available for the elderly. The elderly support ratio was 1:5 in 2000 (20.1 people >= 65 for every 100 people aged 18 to 64). This ratio is expected to remain stable through 2010 and then to change steadily--a result of baby boomers turning 65 and the low birth rates of the 1960s and 1970s. Between 2030 and 2040, this ratio is projected to be about 1:3 (35 people >= 65 for every 100 people aged 18 to 64).

The geographic distribution and migration patterns of the elderly in the US affect medical and long-term care services. In 2000, > 3.5 million people >= 65 lived in California; > 2.4 million lived in New York and Florida; and > 1 million lived in Pennsylvania, Texas, Illinois, Ohio, Michigan, and New Jersey. The 10 states with the highest percentage of people >= 65 were (in decreasing order) Florida, Pennsylvania, West Virginia, Iowa, North Dakota, Rhode Island, Maine, South Dakota, Arkansas, and Connecticut; in all but Connecticut, the percentage was >= 14%. Many elderly people move to Florida; the high percentage of elderly people in the other states results primarily from younger people moving out of those states.

The number of elderly people in all states increased in the 1990s. Between 1990 and 2000, the greatest percentage increases occurred in Nevada (71.5%), Alaska (59.6%), Arizona (39.5%), New Mexico (30.1%), Hawaii (28.5%), Utah (26.9), Colorado (26.3%), Delaware (25.9%), South Carolina (22.3%), and Wyoming (22.2%). People >= 75 have been relocating to the South and West since the 1970s.

Mortality and Morbidity Rates

Life expectancy at all ages increased dramatically during the 20th century. Life expectancy at birth increased by 14 yr between 1900 and 1940. It has increased for people >= 65 mainly since 1940. Life expectancy at age 65 increased by nearly 2 yr between 1940 and 1954, remained stable between 1954 and 1968, and increased steadily by 3.5 yr between 1968 and 2001--from 14.6 to 18.1 yr.

In 2001, life expectancy at birth was 5.4 yr longer for women than for men; among blacks, women lived 6.9 yr longer (see Table 2-2). With increasing age, the difference in life expectancy for women and men decreased--to about 1 yr at age 85. At birth, life expectancy was 5.5 yr longer for whites than for blacks; it was 1.8 yr longer at age 65 but nearly equal at age 85.

In 2002, the overall mortality rate for people >= 65 was 5.1%/yr. Of the 1.8 million deaths in this age group, 31.8% resulted from heart disease, 21.6% from cancer, and 7.9% from cerebrovascular disease (see Table 2-3). However, because multiple chronic disorders are common, cause of death is often arbitrarily assigned, especially for the oldest old. Physicians should therefore be more specific when completing death certificates. To be useful, cause-of-death statistics require accurate death certification, including a careful listing of the probable pathologic sequence of events with the underlying or likely causative disorder listed on the certificate. In elderly patients with multiple disorders, other significant causes may need to be added.

In 2002, mortality rates for heart disease, cerebrovascular disease, and pneumonia and influenza increased exponentially after age 55. In contrast, after age 65, mortality rates for cancer and chronic lower respiratory disease increased less rapidly. In people >= 85, the mortality rate for cerebrovascular disease nearly equaled the mortality rate for cancer; the mortality rates for pneumonia and influenza, the 4th leading causes of death, surpassed the mortality rate for chronic lower respiratory disease (see Figure 2-2).

The increase in life expectancy for all age groups since the late 1960s is attributable largely to a substantial decrease in the number of deaths due to heart disease and stroke. Between 1980 and 2002, the mortality rate for ischemic heart disease decreased by 50% in people aged 65 to 74, 44% in those aged 75 to 84, and 30% in those >= 85. The mortality rate for cerebrovascular disease decreased by 45% in people aged 65 to 84 and 37% in those >= 85.

In contrast, the cancer mortality rate increased slightly. Between 1980 and 2002, it increased by 7% in people aged 75 to 84 and 8% in those >= 85. More people die of cancer (and other disorders) because fewer people die of heart disease and stroke and because onset of these disorders is postponed until very old age.

Incidence of newly diagnosed cancer increases for most cancers through age 75, then decreases for some cancers. At age 55, prostate cancer is the most common cancer in men and breast cancer is the most common cancer in women. Lung cancer is the 2nd most common cancer in men at all older ages and in women aged 55 to 75. Its incidence peaks in men aged 75 to 80 and in women in their early 70s. Historically, the oldest population segments have had relatively fewer smokers because smokers tend to die of cancer or of other smoking-related disorders at younger ages. Thus, the decrease at the oldest ages may be a survival effect. Colon cancer is the 3rd most common cancer in men aged 55 to 85 and in women aged 55 to 75; in older age groups, its incidence surpasses that of lung cancer.

Disability and Disease

Disability and disease (chronic, multiple, or both), which are prevalent in the elderly, greatly affect functioning level, independence, and the need for long-term care. Functioning level is determined by a person's ability to perform activities of daily living (ADLs)--such as eating, dressing, bathing, transferring between bed and chair, and using the toilet--and instrumental ADLs (IADLs)--such as preparing meals, doing housework, taking drugs as instructed, going on errands, managing finances, and using a telephone. About 5 to 8% of community-dwelling people >= 65 need assistance with one or more ADLs. With aging, the percentage of elderly people who live at home but need assistance or who live in a nursing home increases markedly to 56% of women and 38% of men >= 85.

Chronic disorders that lead to disability include those that also commonly cause death (eg, heart disease, stroke, chronic lower respiratory disease, diabetes) and those that are less likely to cause death but affect functioning (eg, arthritis, osteoporosis, vision and hearing impairment). Chronic disorders that people >= 65 report most frequently include hypertension, arthritis, hearing impairment, coronary artery disease, a history of cancer, and diabetes (see Table 2-4).

Comorbidity becomes more prevalent with aging; most of the oldest old have comorbidities. Similarly, disability becomes more prevalent, increasing with aging and with the number of chronic disorders. Developing effective interventions that prevent disease and reduce disability is critical for improving quality of life of the elderly and controlling health care costs.

Use of Health Care Services

The aging of the population will greatly affect costs of health care services for the elderly.

Hospitalization: In 2002, people >= 65 accounted for 12.7 million of the 31.7 million hospitalizations in the US and spent > 74 million days in the hospital; these findings explain why about 40% of hospital revenue comes from Medicare. In 2000, the leading causes of hospitalization for men and women >= 65 were cardiovascular and GI disorders. For people >= 85, the leading causes of hospitalization were cardiovascular disorders, followed by pneumonia for men and GI disorders for women. In men and women in the oldest age group, volume depletion accounts for more hospitalizations than cancer.

Between 1985 and 2000, hospitalization rates for cancer progressively decreased from 34.8 to 17.5/1000 people in the total population (at least partly because of more outpatient procedures), and rates for pneumonia increased from 15.4 to 22.1/1000 people. Hospitalization rates for benign prostatic hyperplasia decreased markedly from 16.4 to 6.0/1000 people between 1985 and 2000 (again, at least partly because of more outpatient procedures).

Length of stay decreased dramatically between 1990 and 2002, mostly because reimbursement for hospitalization of Medicare patients changed. For people >= 65, decreases occurred in all disease categories. A hospital stay that lasted 7 to 10 days in 1990 now lasts about 5 to 6 days.

In 2002, cardiac diagnostic and surgical procedures accounted for 4 of the 5 most common surgical procedures in the elderly. Per 100,000 people >= 65, there were 3561 cardiac catheterizations, 932 coronary artery bypass graft surgeries, 1023 pacemaker insertions, and 2654 angioplasties (data is based on hospital discharges). The rate for pacemaker insertions in people >= 65 was 8 times that in people aged 45 to 64, and the rate for other procedures was about twice that in the younger group. For people >= 85, the most common procedure was pacemaker implantation (155/10,000 population); the 2nd most common procedure was hip replacement (126/10,000 population) in women and prostatectomy (111/10,000 population) in men.

Outpatient visits: In 2002, people >= 65 made more than 224 million visits to a physician's office, accounting for 25% of all visits. Those aged 65 to 74 averaged 6.1 visits per year, and those >= 75 averaged 7.2 visits per year. The most common reasons for visits were routine chronic problems, acute problems, flare-ups of a chronic problem, preventive care, and presurgical or postsurgical assessments. The most common diagnoses in people >= 65 were hypertension, acute upper respiratory infection, diabetes mellitus, and arthropathies.

Institutionalization: According to 1999 statistics, about 1.5 million elderly people (4% of the elderly; 1% of those aged 65 to 74; 12% of men and 21% of women >= 85) live in nursing homes at some point in time. Of people who reach age 65, 52% of women and 33% of men will spend some time in a nursing home. Of women who die after age 89, 70% have lived in a nursing home for at least some time. Of all people currently living in nursing homes, 43% have lived in one for < 1 yr, 43% have lived in one for 1 to 5 yr, and 14% have lived in one for >= 5 yr.

In 1999, about 95% of nursing home residents received assistance with one or more ADLs, 58% had difficulty controlling bowels or bladder, 63% used a wheelchair, and 26% used a walker. Risk factors for institutionalization include being widowed, living alone, having reduced family and social support, having a reduced income, being mentally disoriented or cognitively impaired, having multiple chronic disorders, being incontinent, and needing assistance with ADLs or IADLs or with ambulation.

Nursing home admission rates are lower for blacks than for whites, suggesting that such factors as cultural preferences and access to care may affect admission. The primary sources of payment for nursing home residents are Medicaid (59%), private sources (24%), Medicare (15%), and other government assistance and charity (3%).

Last year of life: Of total Medicare expenditures for a given year, > 25% are for services during enrollees' last year of life; ½ this amount is spent during the last 60 days. Health care expenditures for enrollees during their last year are 7 times higher than those for other enrollees; however, Medicare pays for only about 1/3 of these expenses. Expenditures before death are less among the oldest old than among the rest of the elderly population. Expenditures during the last year of life also relate to the cause of death (eg, Medicare expenditures are about twice as high for people dying of cancer as for those dying of heart or cerebrovascular disease).

This topic was last updated September 2005.