Estimates of probable dementia prevalence from population-based surveys compared with dementia prevalence estimates based on meta-analyses

<p>Abstract</p> <p>Background</p> <p>National data on dementia prevalence are not always available, yet it may be possible to obtain estimates from large surveys that include dementia screening instruments. In Australia, many of the dementia prevalence estimates are based on European data collected between 15 and 50 years ago. We derived population-based estimates of probable dementia and possible cognitive impairment in Australian studies using the Mini-Mental State Examination (MMSE), and compared these to estimates of dementia prevalence from meta-analyses of European studies.</p> <p>Methods</p> <p>Data sources included a pooled dataset of Australian longitudinal studies (DYNOPTA), and two Australian Bureau of Statistics National Surveys of Mental Health and Wellbeing. National rates of probable dementia (MMSE < 24) and possible cognitive impairment (24-26) were estimated using combined sample weights.</p> <p>Results</p> <p>Estimates of probable dementia were higher in surveys than in meta-analyses for ages 65-84, but were similar at ages 85 and older. Surveys used weights to account for sample bias, but no adjustments were made in meta-analyses. Results from DYNOPTA and meta-analyses had a very similar pattern of increase with age. Contrary to trends from some meta-analyses, rates of probable dementia were not higher among women in the Australian surveys. Lower education was associated with higher prevalence of probable dementia. Data from investigator-led longitudinal studies designed to assess cognitive decline appeared more reliable than government health surveys.</p> <p>Conclusions</p> <p>This study shows that estimates of probable dementia based on MMSE in studies where cognitive decline and dementia are a focus, are a useful adjunct to clinical studies of dementia prevalence. Such information and may be used to inform projections of dementia prevalence and the concomitant burden of disease.</p

Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model

<p>Abstract</p> <p>Background</p> <p>Alzheimer's Disease (AD) affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development.</p> <p>Methods</p> <p>A time-to-event (TTE) simulation provided estimates of screening asymptomatic patients in the general population age ≥55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death.</p> <p>Results</p> <p>The base case results indicated increased AD free years (AD-FYs) through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years) the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90).</p> <p>Conclusions</p> <p>This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.</p

Effect of diabetes on caregiver burden in an observational study of individuals with Alzheimer’s disease

Background The burden on caregivers of patients with Alzheimer’s disease (AD) is associated with the patient’s functional status and may also be influenced by chronic comorbid medical conditions, such as diabetes. This post-hoc exploratory analysis assessed whether comorbid diabetes in patients with AD affects caregiver burden, and whether caregivers with diabetes experience greater burden than caregivers without diabetes. Caregiver and patient healthcare resource use (HCRU) were also assessed. Methods Baseline data from the GERAS observational study of patients with AD and their caregivers (both n = 1495) in France, Germany and the UK were analyzed. Caregiver burden was assessed using the Zarit Burden Interview (ZBI). Caregiver time on activities of daily living (ADL: basic ADL; instrumental ADL, iADL) and supervision (hours/month), and caregiver and patient HCRU (outpatient visits, emergency room visits, nights hospitalized) were assessed using the Resource Utilization in Dementia instrument for the month before the baseline visit. Regression analyses were adjusted for relevant covariates. Time on supervision and basic ADL was analyzed using zero-inflated negative binomial regression. Results Caregivers of patients with diabetes (n = 188) were younger and more likely to be female (both p < 0.05), compared with caregivers of patients without diabetes (n = 1307). Analyses showed caregivers of patients with diabetes spent significantly more time on iADL (+16 %; p = 0.03; increases were also observed for basic ADL and total caregiver time but did not reach statistical significance) and had a trend towards increased ZBI score. Patients with diabetes had a 63 % increase in the odds of requiring supervision versus those without diabetes (p = 0.01). Caregiver and patient HCRU did not differ according to patient diabetes. Caregivers with diabetes (n = 127) did not differ from those without diabetes (n = 1367) regarding burden/time, but caregivers with diabetes had a 91 % increase in the odds of having outpatient visits (p = 0.01). Conclusions This cross-sectional analysis found caregiver time on iADL and supervision was higher for caregivers of patients with AD and diabetes versus without diabetes, while HCRU was unaffected by patient diabetes. Longitudinal analyses assessing change in caregiver burden over time by patient diabetes status may help clarify the cumulative impact of diabetes and AD dementia on caregiver burden

Dementia and cognition in the oldest-old

Introduction Fueled by medical and technological advances, average life expectancy in the USA has increased by more than 25 years over the past century. A consequence of increased longevity and the aging of the “baby boomers” is that the oldest-old (age 90 or older) have become the fastest growing segment of the US population. Currently, there are fewer than 2 million Americans aged 90 and older, but this number will increase to approximately 10 million by 2050. In terms of percentage of the population, those aged 90 and older presently represent 0.5% of the population in the USA, while by the middle of the twenty-first century, they will form about 2.5% of the population as depicted in Fig. 17.1. Moreover, the increases in the oldest-old population are occurring worldwide. Countries including Japan, France, Italy and Germany are expected to have between 3 and 5% of their population aged 90 and over by 2050. Cognition in the oldest-old: key questions What is the prevalence of dementia in the oldest-old? What are the causes of dementia in the oldest-old? How can we screen for dementia in this population and what challenges must we overcome in the cognitive assessment of this age group? What are the clinical–pathological correlates of dementia in the oldest-old? The rapidly growing population over the age of 90 signals a need to understand aging and age-related conditions in the oldest-old. Many issues require investigation in these pioneers of aging. Estimates of dementia prevalence vary as described in more detail below

Psychometric properties of the 3MS and MMSE in the oldest-old: Sensitivity and specificity

OBJECTIVE: To compare the sensitivity and specificity of the Modified Mini-Mental State Examination (3MS) and Mini-Mental State Examination (MMSE) in a sample of 90t years old. BACKGROUND: The 3MS and MMSE are common screening measures used in research and clinical settings. Psychometric investigations of these scales rarely include 90+ year olds. DESIGN/METHODS Participants are from the 90-t Study, a longitudinal study of aging and dementia. A clinical diagnosis of normal, codtive impairment not demented, or demented was assigned by a neuroexaminer based on DSM-IV criteria. The 438 participants who completed ail items on the 3MS and derived MMSE are included (5040 with college education or higher, mean age of 95). ROC analyses were conducted to compare: 1) normal versus cognitive impairment (CI); and 2) non-demented versus demented. RESULTS The 3MS had better overall accuracy than the MMSE in differentiating between normal and CI (3MS Area Under the Curve [AUC] = .93 vs. MMSE AUC = .90). The suggested cut-off point for CI on the 3MS is 589 (sens. = .85, spec. = .83). The overall accuracy of the 3MS and MMSE in differentiating between nondemented and demented was the same (AUC = .93). In identifying the normal versus CI groups, the 3MS had better specificity than the MMSE when holding sensitivity constant. In the nondemented versus demented comparison, the MMSE had better specificity than the 3MS. The suggested cut-off point for dementia on the MMSE is 524 (sens. = .85, spec. = .81). CONCLUSIONS/RELEVANCE Both the 3MS and MMSE had high sensitivity and specificity. The 3MS appears to be a slightly better screening measure than the MMSE for identifying CI in the oldest-old, and the MMSE may be slightly better than the 3MS at correctly ruling out those who do not have dementia. Supported by: NIH grant R01AG021055 and the Al and Trish Nichols Chak in Clinical Neuroscience

Detection, diagnosis, and treatment of Alzheimer&rsquo;s disease dementia stratified by severity as reported by caregivers in Japan

William Montgomery,1 Amir Goren,2 Kristin Kahle-Wrobleski,3 Tomomi Nakamura,4 Kaname Ueda5 1Global Patient Outcomes &amp; Real World Evidence, Eli Lilly Australia, NSW, Australia; 2Real World Evidence, Kantar Health, New York, NY, USA; 3Global Patient Outcomes and Real World Evidence, Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, USA; 4Bio-Medicines, Medical Development Unit, Eli Lilly Japan K.K., Tokyo, Japan; 5Health Outcomes, Health Technology Assessment, &amp; Real World Evidence, Medical Development Unit, Eli Lilly Japan K.K., Kobe, Japan Background: Dementia of Alzheimer&rsquo;s disease (AD) imposes burdens on patients, caregivers, and society. This cross-sectional study examined caregiver-reported history of disease onset and AD dementia to inform efforts promoting early disease detection and diagnosis.Methods: An online survey collected self-reported cross-sectional data &ndash; demographic characteristics, diagnosis, treatment experiences, and other information on disease detection, diagnosis, and treatment &ndash; from caregivers of patients with AD dementia. These characteristics were examined as a function of AD dementia severity.Results: Three hundred patients with AD dementia were trichotomized by long-term care insurance levels reported by caregivers: 12.3% (n=37) as low severity, 63.7% (n=191) as medium severity, and 24.0% (n=72) as high severity. The Short-Memory Questionnaire and patient dependency scores both varied significantly across severity groups. AD dementia symptoms were most frequently first detected by a caregiver (58.7%) or the patient&rsquo;s family (45.7%). However, in 13.7% of cases, symptoms were detected by a health care provider during a routine visit. Memory problems were the most frequent first symptoms (77.3%), followed by repetition (55.7%). Patients (73.7%) were taking symptomatic treatment such as acetylcholinesterase inhibitors or memantine. High-severity patients were older, had been diagnosed with AD dementia for a longer time, had more frequent reports of memory problems as the first symptoms detected, and required more hours of care per day, compared with low-severity patients.Conclusion: Caregivers and families play an integral role in the identification of AD dementia patients, with memory problems being common first symptoms noticed by caregivers that led to a diagnosis of AD dementia. These results provide novel insight into the detection, diagnosis, and treatment of AD dementia in Japan and how these factors differ across the spectrum of disease severity. Keywords: Alzheimer&rsquo;s disease dementia, Japan, disease history, caregivers, treatment patter