A Comparison of the Prevalence of Dementia in the United States in 2000 and 2012

Abstract

IMPORTANCEThe aging of the US population is expected to lead to a large increase in the number of adults with dementia, but some recent studies in the United States and other high-income countries suggest that the age-specific risk of dementia may have declined over the past 25 years. Clarifying current and future population trends in dementia prevalence and risk has important implications for patients, families, and government programs. OBJECTIVE To compare the prevalence of dementia in the United States in 2000 and 2012. DESIGN, SETTING, AND PARTICIPANTS We used data from the Health and Retirement Study (HRS), a nationally representative, population-based longitudinal survey of individuals in the United States 65 years or older from the 2000 (n = 10 546) and 2012 (n = 10 511) waves of the HRS.MAIN OUTCOMES AND MEASURES Dementia was identified in each year using HRS cognitive measures and validated methods for classifying self-respondents, as well as those represented by a proxy. Logistic regression was used to identify socioeconomic and health variables associated with change in dementia prevalence between 2000 and 2012. RESULTSThe study cohorts had an average age of 75.0 years (95% CI, 74.8-75.2 years) in 2000 and 74.8 years (95% CI, 74.5-75.1 years) in 2012 (P= .24); 58.4% (95% CI, 57.3%-59.4%) of the 2000 cohort was female compared with 56.3% (95% CI, 55.5%-57.0%) of the 2012 cohort (P< .001). Dementia prevalence among those 65 years or older decreased from 11.6% (95% CI, 10.7%-12.7%) in 2000 to 8.8% (95% CI, 8.2%-9.4%) (8.6% with ageand sex-standardization) in 2012 (P < .001). More years of education was associated with a lower risk for dementia, and average years of education increased significantly (from 11.8 years [95% CI,9 years] to 12.7 years [95% CI, 12.6-12.9 years]; P < .001) between 2000 and 2012. The decline in dementia prevalence occurred even though there was a significant age-and sex-adjusted increase between years in the cardiovascular risk profile (eg, prevalence of hypertension, diabetes, and obesity) among older US adults. CONCLUSIONS AND RELEVANCEThe prevalence of dementia in the United States declined significantly between 2000 and 2012. An increase in educational attainment was associated with some of the decline in dementia prevalence, but the full set of social, behavioral, and medical factors contributing to the decline is still uncertain. Continued monitoring of trends in dementia incidence and prevalence will be important for better gauging the full future societal impact of dementia as the number of older adults increases in the decades ahead.

Neuropsychiatric Symptoms in Alzheimer Disease, Vascular Dementia, and Mixed Dementia

“…Cerebrovascular disease is preventable and modification of lifestyle has been recognized to have a significant impact on decreasing the incidence and prevalence of vascular disease dementia [45,46] and dementia more broadly [25]. Given that VaD had the greatest prevalence of NPS, which are the leading cause of institutionalization, there is enormous societal benefit to implementing prevention programs for vascular disease.…”

“…Most recently, it has been suggested that ischemic small vessel disease is likely associated with psychosis in AD [24] Thus, by better understanding the underlying vascular changes that are associated with certain NPS, we can better target treatment options, arguing for more aggressive treatment for vascular disease. Langa et al [25] recently conducted a study in the USA that found a significantly decreased prevalence of dementia in the year 2012 when compared to the prevalence in 2000 for subjects aged 65 years or older. Furthermore, the authors suggest that “increasing educational attainment and better control of cardiovascular risk factors may have contributed to the improvement, but the full set of social, behavioral, and medical factors contributing to the improvement is still uncertain” [25].…”

“…Langa et al [25] recently conducted a study in the USA that found a significantly decreased prevalence of dementia in the year 2012 when compared to the prevalence in 2000 for subjects aged 65 years or older. Furthermore, the authors suggest that “increasing educational attainment and better control of cardiovascular risk factors may have contributed to the improvement, but the full set of social, behavioral, and medical factors contributing to the improvement is still uncertain” [25]. Therefore, in better understanding the vascular changes that are associated with NPS, we can also potentially better manage the incidence of dementia.…”

Scores Obtained from a Simple Cognitive Test of Visuospatial Episodic Memory Performed Decades before Death Are Associated with the Ultimate Presence of Alzheimer Disease Pathology

“…We used 27 items from this test to assign a TICS27 score [22]. Using thresholds defined in this report, we classified participants as follows: 0–6 = dementia; 7–11 = cognitive impairment not dementia; and 12–27 = normal cognition.…”

Research update on Alzheimer’s disease and introduction to the Expert Review of Neurotherapeutics special issue

“…Prevention of AD is thus clearly the current preferred alternative [8], and national plans in many countries are encouraging higher education and healthier lifestyles. The decrease in prevalence of dementia in the United States between 2000 and 2012 is attributed primarily to an increase in educational attainment [9], and other countries are reporting reductions attributed to stricter control of vascular risk factors in mid-life. An excellent overall perspective on how to defeat dementia has been written by science writer Elie Dolgin, in his feature news [10].…”