Deaths from Alzheimer’s Disease — United States, 1999–2014

Weekly / May 26, 2017 / 66(20);521–526

Christopher A. Taylor, PhD1; Sujay F. Greenlund2; Lisa C. McGuire, PhD1; Hua Lu, MS1; Janet B. Croft, PhD1 (View author affiliations)

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Summary

What is already known about this topic?

Alzheimer’s disease (Alzheimer’s) is the most common cause of dementia. It currently affects an estimated 5.5 million adults in the United States and is expected to affect 13.8 million U. S. adults aged ≥65 years by 2050.

What is added by this report?

Age-adjusted rates of Alzheimer’s mortality significantly increased in 41 states and the District of Columbia from 1999 to 2014. Counties with the highest age-adjusted rates were primarily in the Southeast, plus some additional areas in the Midwest and West. Significant increases in Alzheimer’s deaths coupled with an increase in the number of persons with Alzheimer’s dying at home suggest that the burden on caregivers has increased even more than the increase in the number of deaths.

What are the implications for public health practice?

Given the increasing number of Alzheimer’s deaths and persons with Alzheimer’s dying at home, there is a growing number of caregivers who likely can benefit from interventions like education, respite care, and home health assistance; such interventions can lessen the burden of caregiving and can improve the care received by persons with Alzheimer’s.

Christopher A. Taylor, PhD1; Sujay F. Greenlund2; Lisa C. McGuire, PhD1; Hua Lu, MS1; Janet B. Croft, PhD1 (View author affiliations)

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Alzheimer’s disease (Alzheimer’s), an ultimately fatal form of dementia, is the sixth leading cause of death in the United States, accounting for 3.6% of all deaths in 2014 (1,2). Alzheimer’s deaths can be an indicator of paid and unpaid caregiver burden because nearly everyone in the final stages of Alzheimer’s needs constant care, regardless of the setting, as the result of functional and cognitive declines (2). To examine deaths with Alzheimer’s as the underlying cause, state-level and county-level death certificate data from the National Vital Statistics System for the period 1999–2014 were analyzed. A total of 93,541 Alzheimer’s deaths occurred in the United States in 2014 at an age-adjusted (to the 2000 standard population) rate of 25.4 deaths per 100,000 population, a 54.5% increase compared with the 1999 rate of 16.5 deaths per 100,000. Most deaths occurred in a nursing home or long-term care facility. The percentage of Alzheimer’s decedents who died in a medical facility (e.g., hospital) declined from 14.7% in 1999 to 6.6% in 2014, whereas the percentage who died at home increased from 13.9% in 1999 to 24.9% in 2014. Significant increases in Alzheimer’s deaths coupled with an increase in the number of persons with Alzheimer’s dying at home have likely added to the burden on family members or other unpaid caregivers. Caregivers might benefit from interventions such as education, respite care, and case management that can lessen the potential burden of caregiving and can improve the care received by persons with Alzheimer’s.

Mortality data for 1999–2014 were analyzed using CDC WONDER (https://wonder.cdc.gov). The data were provided by the National Vital Statistics System and based on information from all resident death certificates filed in the 50 states and the District of Columbia (DC). The period analyzed represented all of the years with U.S. mortality data available at the time of analysis* using the International Classification of Disease, Tenth Revision (ICD-10) code set, which was implemented in 1999. CDC WONDER queries were used to generate the number of deaths with Alzheimer’s reported as the underlying cause of death, along with unadjusted and age-adjusted death rates with 95% confidence intervals and standard errors for groups defined by characteristics including year, sex, age group (≤64, 65–74, 75–84, and ≥85 years), race/ethnicity (non-Hispanic white, non-Hispanic black, American Indian/Alaska Native, Asian/Pacific Islander, or Hispanic), urban-rural classification, state, and county.

The percentages of Alzheimer’s deaths that occurred in medical facilities, the decedent’s home, hospice facility, or nursing home/long-term care facilities also were obtained. County-level data were examined for the aggregated years of 2005–2014 because the geographic distribution for 1999–2004 data were inconsistent with more recent data and would have obscured any current geographic patterns. ICD-10 codes G30.0, G30.1, G30.8, and G30.9 were used to identify Alzheimer’s as the underlying cause of death. These codes are used by CDC to describe Alzheimer’s as a leading cause of death (1). Other forms of dementia were not examined in this analysis.

Mortality rates were calculated using population estimates produced by the U.S. Census Bureau in collaboration with CDC’s National Center for Health Statistics. Age-adjusted mortality rates were calculated using the 2000 U.S. standard population. The z-statistic (assuming a normal approximation for the distribution of rates) was used to compare rates at a statistical significance level of p<0.05. No adjustment was made for multiple comparisons. Joinpoint regression was used to test the significance of trends in age-specific rates for the period 1999–2014.

From 1999 to 2014, age-specific rates of deaths attributed to Alzheimer’s increased among adults aged 75–84 years from 129.5 to 185.6 per 100,000 population and among adults aged ≥85 years, from 601.3 to 1,006.8. The largest increase in the rates of Alzheimer’s deaths among adults aged ≥85 years occurred from 1999 to 2005, compared with 2005–2014 (p<0.001) (Figure 1). Since 2005, although the mortality rate has continued to increase, the rate of increase was not as large as 1999–2005.

The age-adjusted Alzheimer’s death rate per 100,000 population increased from 16.5 (44,536 deaths) in 1999 to 25.4 (93,541 deaths) in 2014, an increase of 54.5% (Table). In 2014, rates were higher compared with 1999 among all age groups; also in 2014 rates were higher among women compared with men and among non-Hispanic whites compared with other racial/ethnic populations (Table). In 2014, death rates for Alzheimer’s were lower among residents of large central metropolitan areas and large fringe metropolitan areas compared with residents in other urban-rural classifications.

From 1999 to 2014, rates of Alzheimer’s deaths significantly increased for 41 states and DC (Table). Only one state, Maine, had a significant decrease in age-adjusted Alzheimer’s deaths. Age-adjusted rates for all 50 states and DC ranged from 7.0 to 29.8 per 100,000 in 1999 and from 10.7 to 43.6 per 100,000 in 2014.

Using average annual county-level data for the period 2005–2014, age-adjusted rates of Alzheimer’s deaths ranged from 4.3 to 123.7 per 100,000 (Figure 2). Counties with the highest age-adjusted rates were primarily in the Southeast, plus some additional areas in the Midwest and West.

Most Alzheimer’s decedents died in a nursing home or long-term care facility in 1999 (67.5%) and 2014 (54.1%). The percentage who died in a medical facility declined from 14.7% in 1999 to 6.6% in 2014. In contrast, the percentage who died at home increased from 13.9% in 1999 to 24.9% in 2014, with an additional 6.1% who died in a hospice facility in 2014.

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Discussion

Symptoms of early stage Alzheimer’s include memory loss that interferes with daily activities, difficulties with problem solving, losing or misplacing objects, and changes in mood and personality. As Alzheimer’s progresses, the brain’s ability to control language and reasoning becomes impaired. Persons might have problems recognizing family and friends or performing multistep tasks such as getting dressed. In advanced stages, persons with Alzheimer’s might be bedridden, have difficulty communicating, swallowing, or controlling bowel or bladder functions (2).

Adults aged ≥65 years are at greatest risk for developing Alzheimer’s (2). The number of Alzheimer’s deaths has increased, in part, because of a growing population of older adults. With the number of older adults increasing, the prevalence of Alzheimer’s is projected to quadruple by 2050 (3). However, age-adjusted rates of Alzheimer’s deaths have been increasing since 1979 (4). Although the actual number Alzheimer’s deaths might be increasing, the increase in the rate of Alzheimer’s deaths might also be attributed to increases in premorbid Alzheimer’s diagnosis by patients seeking care for symptoms and increased reporting by physicians, coroners, and medical examiners who assign causes of death.

Studies have shown that non-Hispanic blacks and Hispanics are more likely to have Alzheimer’s because of a wide variety of factors including increased cardiovascular disease risk factors (5). In contrast, this analysis showed that non-Hispanic whites have higher rates of Alzheimer’s deaths. The causes of the racial differences in the increase in Alzheimer’s death rates might be the result of competing causes of mortality; when compared with non-Hispanic whites, non-Hispanic blacks have higher rates for death from cardiovascular disease at younger ages (6).

It is important to note that the largest increase in the mortality rate occurred in older adults aged ≥85 years for the years 1999–2005. Since 2005, the mortality rate in this age group has continued to increase, but at a slower pace. This study did not directly examine factors that might have contributed to the sharp increase in reported deaths from 1999 to 2005 or the subsequent slowing of this increase. Increases in the mortality rate for Alzheimer’s might be the result of corresponding decreases in mortality rates for competing causes of death, including cardiovascular disease and stroke (2,6).

The increasing rates of Alzheimer’s deaths are not only problematic because of their obvious direct health effects on persons with Alzheimer’s. The debilitating nature of Alzheimer’s means that there are financial and societal costs borne by patients and their families, and by states and counties that operate publicly funded long-term care facilities. It is estimated that total health and long-term care costs for persons with Alzheimer’s and other dementias in the United States will total $259 billion in 2017, more than two thirds of which is expected to be covered by public sources such as Medicare and Medicaid (2). Additionally, most care provided to older adults with Alzheimer’s who do not live in long-term care facilities is provided by family members or other unpaid caregivers (7). In 2015, caregivers of persons with dementia, including Alzheimer’s, provided 18.2 billion hours of unpaid assistance (2). These caregiving hours might correspond to increased financial costs for caregivers and decreased work productivity, as caregivers might take leave from work to ensure adequate care is provided. The societal costs are substantial when considered in the context of the estimated 5.5 million U.S. residents who live with Alzheimer’s (2).

The findings in this report are subject to at least three limitations. First, several factors relating to the assigned cause of death might affect estimates of death involving Alzheimer’s. Evidence suggests that Alzheimer’s deaths reported on death certificates might be underestimates of the actual number of Alzheimer’s deaths in the United States (8). Because cases were identified using the underlying cause of death, persons with Alzheimer’s but a non-Alzheimer’s underlying cause of death were not identified in this analysis. Second, complications from Alzheimer’s, such as pneumonia, might be reported as the cause of death although the actual underlying cause of death, Alzheimer’s, was not reported on the death certificate. Finally, a person with Alzheimer’s might have dementia assigned as the underlying cause of death rather than a more specific diagnosis of Alzheimer’s.

Some modifiable risk factors for cardiovascular disease, such as obesity and fewer years of education, have been identified as factors associated with an increased risk for dementia (9,10). Although some treatments have been demonstrated to alleviate symptoms of Alzheimer’s, there is no cure or definitive means of prevention (2). Until Alzheimer’s can be prevented, slowed, or stopped, caregiving for persons with advanced Alzheimer’s will remain a demanding task. An increasing number of Alzheimer’s deaths coupled with an increasing number of patients dying at home suggests that there is an increasing number of caregivers of persons with Alzheimer’s. It is likely that these caregivers might benefit from interventions such as education, respite care, and case management that can lessen the potential burden of caregiving.

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Corresponding author Christopher A. Taylor, cataylor1@cdc.gov, 770-488-1121.

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1Division of Population Health, National Center for Chronic Disease Prevention and Health Promotion, CDC; 2Georgia State University, Atlanta, Georgia.

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* Before the release of 2015 National Vital Statistics System data on December 9, 2016.

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FIGURE 1. Death rates for Alzheimer’s disease as the underlying cause of death, by age group (years) — United States, 1999–2014

The figure above is a line graph showing the number of deaths per 100,000 population during 1999–2014, by four age groups: ≥85, 75–84, 65–74, and ≤64 years.