The Health and Medical Problems of Older Adults

Among the fears many people have about aging is coping with losses—not only declining mental and physical abilities but also the prospect of failing health, chronic (long-term) illness, and disability. Even though aging is associated with physiological changes, the rate and extent of these changes varies widely. One person may be limited by arthritis at age sixty-five, whereas another is vigorous and active at age ninety.

Despite the increasing proportion of active healthy older adults, it is true that the incidence (the rate of new cases of a disorder over a specified period) and prevalence (the total number of cases of a disorder in a given population at a specific time) of selected diseases as well as the utilization of health-care services increase with advancing age. For example, the incidence of diabetes, heart disease, breast cancer, Parkinson's disease, and Alzheimer's disease increases with age. In contrast, the incidence of other diseases, such as human immunodeficiency virus (HIV) infection, multiple sclerosis, and schizophrenia, decreases with age.

This chapter considers the epidemiology of aging—the distribution and determinants of health and illness in the population of older adults. It describes trends in aging and the health of aging Americans; distinctions among healthy aging, disease, and disability; health promotion and prevention as applied to older people; and selected diseases and conditions common in old age.

GENERAL HEALTH OF OLDER AMERICANS

The proportion of adults rating their health as fair or poor increases with advancing age. In 2004, 17.9% of people aged fifty-five to sixty-four, 22.4% of those aged sixty-five to seventy-four, and 31.5% of adults aged seventy-five and older considered themselves in fair or poor health, compared to just 5.7% of adults aged eighteen to forty-four. (See Table 7.1.)

According to the report Older Americans Update 2006: Key Indicators of Well-Being (May 2006, http://www.agingstats.gov/agingstatsdotnet/Main_Site/Data/2006_Documents/OA_2006.pdf) by the Federal Inter-agency Forum on Aging-Related Statistics, among non-Hispanics, 81% of respondents sixty-five to seventy-four said their health was good or better than good, compared to just 67% of non-Hispanics aged eighty-five and over. Even though the difference is the most dramatic among non-Hispanics, older people of other races and ethnic categories followed the same pattern. Across all older age groups, non-Hispanic respondents were more likely to report good health than non-Hispanic African-American and Hispanic respondents. (See Figure 7.1.)

Older Americans Update 2006 notes that most older people have at least one chronic condition and many have several. Among the most frequently occurring conditions of older adults in 2003–04 were hypertension (48% of men and 55% of women), arthritic symptoms (43% of men and 55% of women), all types of heart disease (37% of men and 28% of women), and cancer (24% of men and 18% of women). (See Figure 7.2.)

Table 7.2 shows that rates of chronic conditions that limited activity among Americans aged sixty-five and older decreased slightly from 38.7% in 1997 to 34.1% in 2004. Among adults aged fifty-five to sixty-four, the conditions most likely to limit activity were arthritis or other musculoskeletal problems, heart or other circulatory disorders, diabetes, lung diseases, vision problems, and senility. Among older people aged sixty-five and over, arthritis and heart disease continue to limit activity most; however, among adults aged eighty-five and over, problems with vision, hearing, and senility also contribute to limiting activity. (See Figure 7.3 and Figure 7.4.)

Instrumental activities of daily living (IADLs) and measures of physical, cognitive, and social functioning are ways to assess disability and often determine whether

older adults can live independently in the community. IADLs include activities such as light housework, meal preparation, laundry, grocery shopping, getting around outside the home, managing money, taking medications as prescribed, and telephoning. Noninstitutionalized individuals are considered chronically disabled if they cannot perform one or more IADL for ninety days or longer. Measures of physical functioning, such as the ability to stoop or kneel, lift heavy objects, walk a few blocks, or reach above the head, are also used to monitor progressive disability.

In 2003 older women reported more difficulties with physical functioning than older men—32% of women were unable to perform at least one physical function task, compared to 18% of men. (See Figure 7.5.)

Hospital Utilization and Physician Visits

Adults aged sixty-five and over have the highest rates of inpatient hospitalization and the longest average lengths of stay (ALOS). In 2004 people aged sixty-five and older had 362.9 hospital discharges per 100,000—nearly one and a half times the number of discharges of adults forty-five to sixty-four. (See Table 7.3.) The highest number of discharges and longest ALOS were among adults seventy-five and older, 470.2 and 5.8 days, respectively.

The ALOS for adults aged sixty-five and older was 5.6 days in 2004, compared to 4.9 days for people aged forty-five to fifty-four. (See Table 7.3.) The ALOS among all age groups has declined since 1980, from a high of 7.5 days to 4.8 days in 2004. Among patients aged seventy-five and older, ALOS decreased by almost one-half, from 11.4 days in 1980 to 5.8 days in 2004.

Shorter stays are in part because of the federal government's introduction of diagnosis-related groups (DRG) in the mid-1980s. (DRGs are categories of illnesses that prescribe, and allow for, set duration of treatment.) DRG-based reimbursement encourages hospitals to discharge patients as quickly as possible by compensating hospitals for a predetermined number of days per diagnosis, regardless of the actual length of stay. Shorter lengths of stay are also attributable to the increasing use of outpatient settings as opposed to hospital admission for an expanding range of procedures such as hernia repairs, gallbladder removal, and cataract surgery.

The growing older population also uses more physician services. Visit rates increase with age among adults aged sixty-five and older and were more than twice as high as visit rates for children and younger adults in 2004. (See Figure 7.6.) Even though women generally make more visits than men, the gender gap practically disappears among older adults.

CHRONIC DISEASES AND CONDITIONS

Chronic diseases are prolonged illnesses such as arthritis, asthma, heart disease, diabetes, and cancer that do not resolve spontaneously and are rarely cured. According to the Centers for Disease Control and Prevention (CDC), in "Chronic Disease Overview" (November 18, 2005, http://www.cdc.gov/nccdphp/overview.htm), chronic illnesses account for 70% of all deaths in the United States. Five of the six leading causes of death among older adults are chronic diseases—heart disease, cancer, cerebrovascular disease (stroke), chronic lower respiratory diseases, and diabetes mellitus. Even though other chronic conditions such as arthritis, asthma, and chronic bronchitis are not immediately life threatening, they compromise the quality of life of affected individuals and place an enormous financial burden on individuals, families, and the U.S. health-care system.

The prevalence of some chronic conditions such as hypertension and diabetes is increasing in the general population and among older adults. In 2003–04 more than half (51.9%) of people sixty-five and older had hyper-tension and 17% suffered from diabetes. (See Table 7.4.) The increase in these conditions is largely attributable to increasing rates of obesity, which is implicated in the development of these and many other chronic conditions.

Arthritis

The word arthritis literally means "joint inflammation," and it is applied to dozens of related diseases known as rheumatic diseases. When a joint—the point where two bones meet—becomes inflamed, swelling, redness, pain, and loss of motion occur. In the most serious forms of the disease, the loss of motion can be physically disabling.

More than one hundred types of arthritis have been identified, but four major types affect large numbers of older Americans:

• Osteoarthritis—the most common type, generally affects people as they grow older. Sometimes called degenerative arthritis, it causes the breakdown of bones and cartilage (connective issue attached to bones) and pain and stiffness in the fingers, knees, feet, hips, and back. In the fact sheet "Osteoarthritis" (June 2006, http://www.rheumatology.org/public/factsheets/oa_new.asp), the American College of Rheumatology reports that about twenty-one million Americans are affected by osteoarthritis. Furthermore, it estimates that 70% of people over seventy have x-ray evidence of osteoarthritis.
• Fibromyalgia—affects the muscles and connective tissues and causes widespread pain, as well as fatigue, sleep problems, and stiffness. Fibromyalgia also causes "tender points" that are more sensitive to pain than other areas of the body. According to the National Fibromyalgia Association (2007, http://www.fmaware.org/site/PageServer?pagename=fibromyalgia), an estimated 3% to 6% of Americans, mostly women, suffer from this condition.
• Rheumatoid arthritis—an inflammatory form of arthritis caused by a flaw in the body's immune system. The result is inflammation and swelling in the joint lining, followed by damage to bone and cartilage in the hands, wrists, feet, knees, ankles, shoulders, or elbows. The Arthritis Foundation (2007, http://www.arthritis.org/disease-center.php?disease_id=31) indicates that rheumatoid arthritis affects about 1% of the Americans, or about 2.1 million people, mostly women.
• Gout—an inflammation of a joint caused by an accumulation of a natural substance, uric acid, in the joint, usually the big toe, knee, or wrist. The uric acid forms crystals in the affected joint, causing severe pain and swelling. This form affects more men than women, claiming about a million sufferers.

PREVALENCE.

Arthritis is a common problem. In "NHIS Arthritis Surveillance" (May 20, 2005, http://www.cdc.gov/arthritis/data_statistics/national_data_nhis.htm#future), the CDC reports that in 2005, 42.7 million Americans had been diagnosed with arthritis and that 8.3 million were disabled by the disease. The total number of people suffering from arthritis is expected to increase to sixty-seven million by 2030, with twenty-five million suffering from a disabling form of the disease. (See Figure 7.7.)

Arthritis is the leading cause of disability in the United States. Rheumatic and musculoskeletal disorders are the most frequently reported cause of impairment in the adult population, the leading cause of limitation of mobility, and the second-leading cause of activity restriction.

Osteoporosis

Osteoporosis is a skeletal disorder characterized by compromised bone strength, which predisposes affected individuals to increased risk of fracture. The National Osteoporosis Foundation (2007, http://www.nof.org/news/index.htm) defines osteoporosis as "about 25% bone loss compared to a healthy young adult or, on a bone density test, 2.5 standard deviations below normal." Even though some bone loss occurs naturally with advancing age, the stooped posture (kyphosis) and loss

of height (greater than one to two inches) experienced by many older adults result from vertebral fractures caused by osteoporosis.

According to Bone Health and Osteoporosis: A Report of the Surgeon General (October 14, 2004, http://www.surgeongeneral.gov/library/bonehealth/content.html), in 2004 about ten million Americans over age fifty had been diagnosed with osteoporosis, and another thirty-four million were considered at risk of developing the condition. Like other chronic conditions that disproportionately affect older adults, the prevalence of bone disease and fractures is projected to increase markedly as the population ages. Bone Health and Osteoporosis notes that each year about 1.5 million people suffer an osteoporotic-related fracture, which often leads to a downward spiral in physical and

mental health—about 20% of older adults who suffer hip fractures die within one year.

Bone Health and Osteoporosis indicates that one out of every two women over fifty will have an osteoporosis-related fracture in her lifetime, with the risk of fracture increasing with age. The aging of the population combined with the historic lack of focus on bone health may together cause the number of hip fractures in the United States to double or even triple by 2020.

One of the goals of the treatment of osteoporosis is to maintain bone health by preventing bone loss and by building new bone. Another is to minimize the risk and impact of falls, because they can cause fractures. Figure 7.8 shows the pyramid of prevention and treatment of osteoporosis. At its base is nutrition (with adequate intake of calcium, vitamin D, and other minerals), physical exercise, and preventive measures to reduce the risk of falls. The second layer of the pyramid involves identifying and treating diseases that can cause osteoporosis, such as thyroid disease. The peak of the pyramid involves drug therapy for osteoporosis. There are two primary types of drugs used to treat osteoporosis. Antiresorptive agents act to reduce bone loss, and anabolic agents are drugs that build bone. Antiresorptive therapies include use of bisphosphonates, estrogen, selective estrogen receptor modulators, and calcitonin. They reduce bone loss, stabilize the architecture of the bone, and decrease bone turnover.

Diabetes

Diabetes is a disease that affects the body's use of food, causing blood glucose (sugar levels in the blood) to become too high. People with diabetes can convert food to glucose, but there is a problem with insulin. In one type of diabetes (insulin-dependent diabetes, or Type 1), the pancreas does not manufacture enough insulin, and in another type (noninsulin dependent, or Type 2), the body has insulin but cannot use the insulin effectively (this latter condition is called insulin resistance). When insulin is either absent or ineffective, glucose cannot get into the cells to be used for energy. Instead, the unused glucose builds up in the bloodstream and circulates through the kidneys. If the blood-glucose level rises high enough, the excess glucose "spills" over into the urine, causing frequent urination. This, in turn, leads to an increased feeling of thirst as the body tries to compensate for the fluid lost through urination.

Type 2 diabetes is most often seen in adults and is the most common type of diabetes in the United States. In Type 2 diabetes the pancreas produces insulin, but it is not used effectively and the body resists responding to it. Heredity is a predisposing factor in the genesis of diabetes, but because the pancreas continues to produce insulin in people suffering from Type 2 diabetes, the disease is considered more of a problem of insulin resistance, in which the body is not using the hormone efficiently.

Because diabetes deprives cells of the glucose needed to function properly, several complications can develop to further threaten the lives of diabetics. The healing process of the body is slowed and there is increased risk of infection. Complications of diabetes include higher risk and rates of heart disease; circulatory problems, especially in the legs, which are often severe enough to require surgery or even amputation; diabetic retinopathy, a condition that can cause blindness; kidney disease that may require dialysis; and dental problems. Close attention to preventive health care, such as regular eye, dental, and foot examinations and tight control of blood sugar levels, have been shown to prevent or delay some of the consequences of diabetes.

Joan Chamberlain and Jane DeMouy, in "Diet and Exercise Dramatically Delay Type 2 Diabetes" (August 6, 2001, http://www.nih.gov/news/pr/aug2001/niddk-08.htm), report that over 80% of people with Type 2 diabetes are overweight, and, in people prone to Type 2 diabetes, becoming over-weight can trigger onset of the disease. It is not known precisely how being overweight contributes to causation of this disease. One hypothesis is that being overweight causes cells to change, making them less effective at using sugar from the blood. This then stresses the cells that produce insulin, causing them to gradually fail. Maintaining a healthy weight and keeping physically fit can usually prevent or delay the onset of Type 2 diabetes.

The relatively recent rise in Type 2 diabetes in the United States is in part attributed to rising obesity among adults. Between 1997 and 2006 the percent of adults diagnosed with diabetes increased from 5% to about 8%. (See Figure 7.9.) Of all adult age groups, the highest rate of diagnosed diabetes was among adults aged sixty-five and over. Worse still, these rates may significantly underestimate the true prevalence of diabetes in the United States in view of National Health and Nutrition Survey findings that show sizeable numbers of adults have undiagnosed diabetes.

Prostate Problems

Prostate problems typically occur after age fifty. There are three common prostate disorders: prostatitis (inflammation of the prostate gland), benign prostatic hyperplasia (BPH; noncancerous enlargement of the prostate), and prostate cancer. Prostatitis causes painful or difficult urination and frequently occurs in younger men. BPH can also create problems with urination, but it is most common in older men. W. Scott McDougal and Michael J. Berry report in Prostate Disease: Finding the Cause and Cure (2004) that more than half of men in their sixties and as many as 90% of men in their eighties and nineties suffer from BPH.

Prostate cancer is the second-most common cause of cancer death after lung cancer in American men and the sixth-leading cause of death of men overall. According to the National Cancer Institute (October 31, 2006, http://www.cancer.gov/cancertopics/factsheet/Detection/early-prostate), in the United States approximately 235,000 men were diagnosed with prostate cancer in 2006 and 27,000 died from it. When it is diagnosed and treated early, prostate cancer is generally not life threatening, because it progresses slowly and remains localized for a long time. As a result, many men who are diagnosed late in life do not die from this disease.

Urinary Incontinence

Urinary incontinence is the uncontrollable loss of urine that is so severe that it has social or hygienic consequences. The National Institute on Aging indicates in "Urinary Incontinence" (August 2002, http://www.niapublications.org/agepages/PDFs/Urinary_Incontinence.pdf) that at least 10% of people aged sixty-five or older suffer from incontinence ranging from mild leakage to uncontrollable and embarrassing wetting. The problem is more common in women than men. Urinary incontinence can lead to many complications. For example, if untreated it increases the risk of developing serious bladder and kidney infections, skin rashes and pressure sores, and falls that result from rushing to use the toilet.

Age-related changes affect the ability to control urination. The maximum capacity of urine that the bladder can hold diminishes, as does the ability to postpone urination when feeling the urge to urinate. As a person ages, the rate of urine flow out of the bladder and through the urethra slows, and the volume of urine remaining in the bladder after urination is finished increases. In women the urethra shortens and its lining becomes thinner as the level of estrogen declines during menopause, decreasing the ability

of the urinary sphincter to close tightly. Among older men, the prostate gland enlarges, sometimes blocking the flow of urine through the urethra. Age-related changes increase the risk for incontinence, but it typically occurs as a symptom of an illness or other medical disorder.

Even though urinary incontinence is common, highly treatable, and frequently curable, it is underdiagnosed and often untreated because sufferers do not seek treatment. Many older adults are fearful, embarrassed, or incorrectly assume that incontinence is a normal consequence of growing old. The disorder exacts a serious emotional toll—sufferers are often homebound, isolated, or depressed and are more likely to report their health as fair to poor than their peers. In addition, urinary incontinence is often a reason for institutionalization, because many of those afflicted have some activity limitations and because incontinence is difficult for caregivers to manage.

Malnutrition

The older population is especially vulnerable to nutrition-related health problems. As people age, their energy needs decline, and it is vital for them to consume nutrient-dense foods in a lower calorie diet. According to the National Resource Center on Nutrition, Physical Activity, and Aging (2007, http://nutritionandaging.fiu.edu/aging_network/malfact2.asp), 35% to 50% of older adults in long-term care facilities and up to 65% of older adults in hospitals as well as an estimated one million homebound older adults are at risk for malnutrition.

Older adults' nutrition may be affected by many factors, including loneliness, depression, a cognitive disorder, a poor appetite, or a lack of transportation. Poor nutrition may arise in response to a major life change such as the death of a spouse. An older adult may forgo meal preparation when there is no longer someone else to

cook for or eat with; and a bereaved or frail older adult may not have the stamina or motivation to shop or cook. Malnutrition may also be the result of poverty. Faced with fixed incomes and competing needs, older adults may be forced to choose between buying food or the prescription medications they need.

Hearing Loss

There are many causes of hearing loss, the most common being age-related changes in the ear's mechanism. Hearing loss is a common problem among older adults and can seriously compromise quality of life. People suffering from hearing loss may withdraw from social contact and are sometimes misdiagnosed as cognitively impaired or mentally ill. In 2004 nearly one-half (48%) of older men and one-third (34%) of older women reported having trouble hearing. (See Figure 7.10.)

Older adults are often reluctant to admit to hearing problems, and sometimes hearing loss is so gradual that even the afflicted person may not be aware of it for some time. For those who seek treatment, there is an expanding array of devices and services to mitigate the effects of hearing loss. Hearing-impaired people may benefit from high-tech hearing aids, amplifiers for doorbells and telephones, infrared amplifiers, and even companion dogs trained to respond to sounds for their owners.

Vision Changes

Almost no one escapes age-related changes in vision. Over time it becomes increasingly difficult to read small print or thread a needle at the usual distance. For many, night vision declines. This is often caused by a condition called presbyopia (tired eyes) and is a common occurrence. People who were previously nearsighted may actually realize some improvement in eyesight as they become slightly farsighted. In 2004, 14% of men and 19% of women aged sixty-five and older reported vision problems. (See Figure 7.10.)

Major Eye Diseases

Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the leading causes of vision impairment and blindness in older adults. Cataracts are the leading cause of blindness in the world. Glaucoma is a chronic disease that often requires life-long treatment to control. Age-related macular degeneration is the most common cause of blindness and vision impairment in Americans aged sixty and older. Diabetic retinopathy is a common complication of diabetes and is considered a leading cause of blindness in the industrialized world.

CATARACTS.

A cataract is an opacity, or clouding, of the naturally clear lens of the eye. The prevalence of cataracts increases dramatically with age and most develop slowly over time as they progressively cause cloudy vision and eventually almost complete blindness. Once a clouded lens develops, surgery to remove the affected lens and replace it with an artificial lens is the recommended treatment. The National Eye Institute (NEI) reports in Vision Problems in the U.S.: Prevalence of Adult Vision Impairment and Age-Related Eye Disease in America (2002, http://www.nei.nih.gov/eyedata/pdf/VPUS.pdf) that each year about 1.5 million cataract surgeries are performed—most are performed as outpatient procedures under local anesthesia—making it the

most common operation in the country. Furthermore, the NEI notes that by age eighty more than half of all Americans have cataracts.

GLAUCOMA.

Glaucoma is a disease that causes gradual damage to the optic nerve, which carries visual information from the eye to the brain. The loss of vision is not experienced until a significant amount of nerve damage has occurred. Because the onset is gradual and insidious, as many as half of all people with glaucoma are unaware of having the disease. In Vision Problems in the U.S., the NEI reports that in the sixty-five to sixty-nine age group the prevalence of glaucoma is about 1.6% for white women and 4.8% for African-American women. Glaucoma affects more than 10% of African-American men and Hispanic women aged eighty and older.

Routine glaucoma testing is especially important for older people. There is no cure for glaucoma and no way to restore lost vision; however, medication can generally manage the condition. At later stages, laser therapy and surgery are effective in preventing further damage.

AGE-RELATED MACULAR DEGENERATION.

Age-related macular degeneration (AMD) is a condition in which the macula, a specialized part of the retina responsible for sharp central and reading vision, is damaged. Symptoms include blurred vision, a dark spot in the center of the vision field, and vertical line distortion. Mary Elizabeth Terzella notes in "Vision Disorders: Understanding Eye Diseases and Conditions" (July–August 2007, http://www.caringtoday.com/node/605) that AMD increases dramatically with age in men and women, and by age seventy-five, one-third of Americans suffer some form of AMD. In "Age-Related Eye Diseases: An Emerging Challenge for Public Health Professionals" (Preventing Chronic Disease, July 2005), Dorothy M. Gohdes et al. note that community surveys reveal that as many as 16% of white women and 12% of white men aged eighty years and older have advanced AMD.

DIABETIC RETINOPATHY.

Diabetic retinopathy occurs when the small blood vessels in the retina do not perform properly. Blood vessels can become blocked, break down, leak fluid that distorts vision, and sometimes release blood into the center of the eye, causing blindness. Laser treatment, called photocoagulation, can help to reduce the risk of loss of vision in advanced cases of diabetic retinopathy. The disorder is a leading cause of blindness, but is less common among older adults than other types of visual impairment. The prevalence of diabetic retinopathy increases with age, reflecting the higher rates of diabetes in older people.

Oral Health Problems

In the press release "CDC Aims to Prevent Oral Diseases among Older Americans" (March 21, 2005, http://asaging.org/media/pressrelease.cfm?id=85), the American Society on Aging reports that the percent of older adults who have retained their teeth has risen from 50% in the 1950s to about 70% in the mid-2000s. Figure 7.10 shows that in 2004, 24% of men and 27% of women aged sixty-five to seventy-four had lost their teeth. For people aged seventy-five and older in 2004, about 31.3% had none of their teeth. (See Table 7.5.) The dramatic improvement in retaining teeth is attributable to improvements in oral health such as water fluoridation, improved oral hygiene, advanced dental techniques, and increased utilization of dental services.

Parkinson's Disease

Parkinsonism refers not to a particular disease but to a condition marked by a characteristic set of symptoms that affects more than 1.5 million people in the United States. Laura Marsh and Ted M. Dawson note in the editorial "Ropinirole May Improve Function, While Minimising Involuntary Movements" (BMJ, July 1, 2000) that about 1% of the population over age fifty suffers from some manifestation of this disorder.

Parkinson's disease (PD) is caused by the death of about half a million brain cells in the basal ganglia. These cells secrete dopamine, a neurotransmitter (chemical messenger). Dopamine's function is to allow nerve impulses to move smoothly from one nerve cell to another. These nerve cells, in turn, transmit messages to the muscles of the body to begin movement. When the normal supply of dopamine is reduced, the messages are not correctly sent, and the symptoms—mild tremor (shaking), change in walking, or a decreased arm swing—of PD appear.

The four early warning signs of Parkinson's disease are tremors, muscle stiffness, unusual slowness (bradykinesia), and a stooped posture. Medications can control initial symptoms, but over time they become less effective. As the disease worsens, patients develop more severe tremors, causing them to fall or jerk uncontrollably. (The jerky body movements PD patients experience are known as dyskinesias.) At other times, rigidity sets in, rendering them unable to move. About one-third of patients also develop dementia, an impairment of cognition.

TREATMENT OF PARKINSON'S DISEASE.

Management of PD is individualized and includes not only drug therapy but also daily exercise. Exercise can often lessen the rigidity of muscles, prevent weakness, and improve the ability to walk.

The main goal of drug treatment is to restore the chemical balance between dopamine and another neurotransmitter, acetylcholine. Most patients are given levodopa (L-dopa), a compound that the body converts into dopamine. Treatment with L-dopa does not, however, slow the progressive course of the disease or even delay the changes in the brain PD produces, and it may produce some unpleasant side effects such as dyskinesias (abnormal involuntary movements).

INFECTIOUS DISEASES

Infectious (contagious) diseases are caused by microorganisms—viruses, bacteria, parasites, or fungi—transmitted from one person to another through casual contact, such as with the transmittal of influenza, or through bodily fluids, such as with the transmittal of HIV, or from contaminated food, air, or water supplies. The CDC reports that in 2004 pneumonia and influenza remained among the top ten causes of death for older adults, responsible for 52,760 deaths of people aged sixty-five and older. (See Table 7.6.) Influenza-related deaths can result from pneumonia as well as from exacerbation of chronic diseases. The CDC (August 23, 2006, http://www.cdc.gov/flu/professionals/diagnosis/) notes that older adults account for more than 90% of deaths attributed to pneumonia and influenza.

Influenza

Influenza (flu) is a contagious respiratory disease caused by a virus. The virus is expelled by an infected individual in droplets into the air and may be inhaled by anyone nearby. It can also be transmitted by direct hand contact. The flu primarily affects the lungs, but the whole body experiences symptoms. Influenza is an acute (short-term) illness characterized by fever, chills, weakness, loss of appetite, and aching muscles in the head, back, arms, and legs. Influenza infection may also produce a sore throat, a dry cough, nausea, and burning eyes. The accompanying fever rises quickly—sometimes reaching 104 degrees—but usually subsides after two or three days. Influenza leaves the patient exhausted.

For healthy individuals, the flu is typically a moderately severe illness, with most adults back to work or school within a week. For the very old and older people who are not in good general health, however, the flu can be severe and even fatal. Complications such as secondary bacterial infections may develop, taking advantage of the body's weakened condition and lowered resistance. The most common bacterial complication is pneumonia, affecting the lungs, but sinuses, bronchi (larger air passages of the lungs), or inner ears can also become secondarily infected with bacteria. Less common but serious complications include viral pneumonia, encephalitis (inflammation of the brain), acute renal (kidney) failure, and nervous system disorders. These complications can be fatal.

Influenza can be prevented by inoculation with a current influenza vaccine, which is formulated annually to contain the influenza viruses expected to cause the flu the upcoming year. Immunization produces antibodies to the influenza viruses, which become most effective after one or two months. The CDC advises that older adults get flu shots early in the fall, because peak flu activity usually occurs around the beginning of the new calendar year. In 2004, 67% of non-Hispanic white, 55% of Hispanic, and 46% of non-Hispanic African-American older adults reported receiving influenza shots within the past twelve months. (See Figure 7.11.) In "Questions & Answers: Flu Shot" (July 24, 2006, http://www.cdc.gov/flu/about/qa/flushot.htm), the CDC reports that immunization reduces hospitalization by 30% to 70% among noninstitutionalized older adults. Among nursing home residents, the flu shot reduces the risk of hospitalization by 50% to 60% and the risk of death by 80%.

Pneumonia

Pneumonia is a serious lung infection. Symptoms of pneumonia are fever, chills, cough, shortness of breath, chest pain, and increased sputum production. Pneumonia may be caused by viruses, bacteria, or fungi; however, the pneumococcus bacterium is the most important cause of serious pneumonia.

In older adults pneumococcal pneumonia is a common cause of hospitalization and death. In "Mortality from Invasive Pneumococcal Pneumonia in the Era of Antibiotic Resistance, 1995–1997" (American Journal of Public Health, February 2000), Daniel R. Feikin et al. indicate that about one-quarter of adults aged sixty-five and older who contract pneumococcal pneumonia develop bacteremia (bacteria in the blood), and nearly one-quarter of those with bacteremia die from it, even with antibiotic treatment.

Older adults are at high risk—two to three times more likely than other adults—to develop pneumococcal infections.

A single vaccination can prevent most cases of pneumococcal pneumonia. The CDC recommends that all people aged sixty-five and older receive the pneumonia vaccine, and, since 1997, an increasing proportion of the older population reports having been vaccinated. In 2004, 60.9% of non-Hispanic white, 38.6% of non-Hispanic African-American, and 33.7% of Hispanic older adults had received a pneumococcal vaccination. (See Table 7.7.)

MANDATORY IMMUNIZATION FOR NURSING HOME RESIDENTS.

Since late 2005 all the estimated 1.5 million residents of the nation's 16,100 nursing homes must be immunized against influenza and pneumonia or the nursing homes will risk losing reimbursement from the Medicare and Medicaid programs. (See Table 3.3 in Chapter 3.) The regulation, which was issued by the Centers for Medicare and Medicaid Services in August 2005, intends to ensure that the most vulnerable older adults receive their flu and pneumococcal vaccinations. People sixty-five and older are among the most vulnerable, especially those in the close quarters of nursing homes where infection can spread more easily.

DISABILITY IN THE OLDER POPULATION

Americans are not only living longer but also are developing fewer chronic diseases and disabilities. The current cohort (a group of individuals that shares a common characteristic such as birth years and is studied over time) of older Americans are defying the stereotype that aging is synonymous with increasing disability and dependence.

In "Change in Chronic Disability from 1982 to 2004/2005 as Measured by Long-Term Changes in Function and Health in the U.S. Elderly Population" (Proceedings of the National Academy of Sciences, November 28, 2006), Kenneth G. Manton, XiLiang Gu, and Vicki L. Lamb report on the 1982 and 2004–05 National Long-Term Care Surveys, which surveyed approximately twenty thousand Medicare enrollees. Manton, Gu, and Lamb note that the proportion of older Americans with a chronic disability significantly declined from 26.5% in 1982 to 19% in 2004–05. Their analysis shows that during this period:

• Chronic disability rates decreased among those over sixty-five with both severe and less severe impairments, with the greatest improvements seen among the most severely impaired. Environmental modifications, assistive technologies, and biomedical advances are believed to have contributed to the observed declines.
• The proportion of people without disabilities increased the most among the oldest adults, rising by 32.6% among those eighty-five years and older.
• The percentage of Medicare enrollees aged sixty-five and older living in long-term care facilities decreased from 7.5% to 4%. The growth of assisted living, changes in Medicare reimbursement, and improved rehabilitation services are possible factors in this decrease in institutionalization.

DRUG USE AMONG OLDER ADULTS

According to Harrison Wein, in "Taking Your Medicine" (NIH Word on Health, April 2001), adults aged sixty-five and older take more prescription and over-the-counter medicines than any other age group. The U.S. Food and Drug Administration (FDA) reports in "Medications and Older People" (September 2003, http://www.fda.gov/fdac/features/1997/697_old.html) that older adults purchase 30% of all prescription drugs and 40% of all over-the-counter medications. Prescription drug costs have skyrocketed since the early 1990s. In 2002 the average cost per person was $1,740. (See Figure 7.12.) Cynthia M. Williams notes in "Using Medications Appropriately in Older Adults" (American Family Physician, November 15, 2002) that older Americans spend an average total of $3 billion annually on prescription medications. Furthermore, she states that more than 60% of older adults are taking at least one prescription medication and that most take an average of three to five medications. These estimates do not include over-the-counter medications, dietary supplements, and other alternative therapies.

Out-of-pocket costs for prescription drugs have increased, creating serious financial hardships for many older adults, especially those Medicare enrollees without supplemental drug coverage. Historically, Medicare did not cover most outpatient prescription drugs; however, Medicare coverage of prescription drugs began in January 2006. It pays for brand-name and generic drugs and offers a choice of prescription drug plans to Medicare beneficiaries.

Older Adults Respond Differently to Drugs

Many factors influence the efficacy, safety, and success of drug therapy with older patients. These factors include the effects of aging on pharmacokinetics—the absorption, distribution, metabolism, and excretion of drugs. Of the four, absorption is the least affected by aging. In older people, absorption is generally complete, just slower. Distribution of most medications is related to body weight and composition changes that occur with aging such as decreased lean muscle mass, increased fat mass, and decreased total body water.

Health professionals who care for older adults know that drug dosages must often be modified based on changing organ function and estimates of lean body mass. They coined the adage "start low and go slow" to guide prescribing drugs for older adults. For example, some initial doses of drugs should be lower because older adults have decreased total body water, which might increase the concentration of the drug. Fat-soluble drugs may also have to be administered in lower doses because they may accumulate in fatty tissues, resulting in longer durations of action. The mechanism used to clear a drug via metabolism in the liver or clearance—excretion—through the kidneys changes with aging and is affected by interactions with other medications. Pharmacodynamics, or tissue sensitivity to drugs, also changes with advancing age. Among older adults, complete elimination of a drug from body tissues, including the brain, can take weeks longer than it might in younger people because of a combination of pharmacokinetic and pharmacodynamic effects.

Adherence, Drug-Drug Interactions,
and Polypharmacy

Adherence—taking prescription medications regularly and correctly—is a challenge for older people who may suffer from memory loss, impaired vision, or arthritis. In "Medications and Older People," the FDA notes that between 40% and 75% of older adults fail to take their medications at the right times and in the right amounts. Strategies to improve adherence include weekly pill boxes, calendars, and easy-to-open bottles with large-print labels.

Drug-drug interactions are more frequent among older adults because they are more likely than people of other ages to be taking multiple medications. The FDA reports in "Medications and Older People" that the average older person takes over four prescription medications at once plus two over-the-counter medications. Dangerous drug-drug interactions may occur when two or more drugs act together to either intensify or diminish one another's potency and effectiveness or when in combination they produce adverse side effects. For example, a person who takes heparin, a blood-thinning medication, should not take aspirin, which also acts to thin the blood. Similarly, antacids can interfere with absorption of certain drugs used to treat Parkinson's disease, hypertension, and heart disease.

Polypharmacy is the use of many medications at the same time. It also refers to prescribing more medication than is needed or a medication regimen that includes at least one unnecessary medication. The major risk associated with polypharmacy is the potential for adverse drug reactions and interactions. Drug-induced adverse events may masquerade as other illnesses or precipitate confusion, falls, and incontinence, potentially prompting the physician to prescribe yet another drug. This "prescribing cascade" is easily prevented. It requires that physicians ensure that all medications prescribed are appropriate, taken correctly, safe, and effective. It may also be prevented by older adults' maintenance of accurate and complete records of all their prescription and over-the-counter drug use.

LEADING CAUSES OF DEATH

According to Yelena Gorina et al., in Trends in Causes of Death among Older Persons in the United States (October 2005, http://0-www.cdc.gov.mill1.sjlibrary.org/nchs/data/ahcd/agingtrends/06olderpersons.pdf), three-quarters of all deaths in the United States occur among people sixty-five years of age and over. During the past fifty years, overall death rates have declined by more than one-third for older people, with chronic diseases responsible for most of the deaths throughout this period.

The top three leading causes of death among adults aged sixty-five and over—heart disease, malignant neoplasms (cancer), and cerebrovascular diseases—were unchanged from 1980 to 2004. (See Table 7.6.) In 2004 Alzheimer's disease, a degenerative disease of the brain that affects many areas of cognitive function, rose to fifth place on the list of leading causes of death and was responsible for 65,313 deaths.

Heart Disease

Even though deaths from heart disease have declined, it still kills more Americans than any other single disease. According to the American Heart Association (2004, http://www.americanheart.org/downloadable/heart/1075718681641FS08OLD4.pdf), 84% of people who die of heart disease are aged sixty-five or older.

Several factors account for the decreasing numbers of deaths from heart disease, including better control of hyper-tension and cholesterol levels and changes in exercise and nutrition. The increasing ranks of trained mobile emergency personnel (paramedics) and wide spread use of cardiopulmonary resuscitation and immediate treatment have also increased the likelihood of surviving an initial heart attack.

Growing use of procedures such as cardiac catheterization, coronary bypass surgery, pacemakers, and angioplasty (a procedure to open narrowed or blocked blood vessels of the heart) and placement of stents (wire scaffolds that hold arteries open) have improved the quality, and in some instances extended the lives, of people with heart disease.

Cancer

Cancer is the second-leading cause of death among older adults. (See Table 7.6.) The American Cancer Society indicates in Cancer Facts and Figures, 2004 (2004, http://www.cancer.org/downloads/STT/CAFF_finalPWSecured.pdf) that about 76% of all cancers are diagnosed after age fifty-five. The likelihood of dying of cancer increases every decade after the age of thirty. In 2004