Incidence Rate Of Dementia Research Articles

Recombinant zoster vaccine and the risk of dementia.

Herpes zoster is a potential risk factor for dementia. The effectiveness of the recombinant zoster vaccine for preventing dementia is uncertain. This retrospective cohort study used de-identified claims data from the Optum Labs Data Warehouse database from January 1, 2017, to December 31, 2022, to determine whether the recombinant zoster vaccine is associated with a reduced risk of dementia. Immunocompetent patients with ≥365days of continuous enrollment were included, with the risk period starting upon age-eligibility for the recombinant zoster vaccination. Cox regression adjusted for time-fixed and time-updated measures every six months was implemented to estimate hazard ratios for dementia. Herpes zoster diagnosis and antiviral therapy were also assessed. There were 4,502,678 individuals (median [IQR] age, 62 [54-71] years; 51% female) included in this study: 206,297 (4.6%) were partially vaccinated, and 460,413 (10.2%) were fully vaccinated. The incidence rate of dementia was 99.1 cases per 10,000 person-years in the fully vaccinated group, 108.2 cases per 10,000 person-years in the partially vaccinated group, and 135.0 cases per 10,000 person-years in the unvaccinated group. After adjustment, vaccination was significantly associated with a decreased risk of dementia for two doses (hazard ratio (HR): 0.68; 95% CI: 0.67-0.70; P<.001) and for one dose (HR 0.89; 95% CI: 0.87-0.92; P<.001). Having a herpes zoster diagnosis before the first vaccination dose was associated with an increased hazard of dementia (HR 1.47; 95% CI: 1.42-1.52; P<.001) compared to those with no diagnosis. Antivirals used to treat zoster infection were protective against dementia (HR 0.42; 95% CI: 0.40-0.44; P<.001). These findings suggest that the recombinant zoster vaccine is associated with a decreased risk of dementia and highlight an additional benefit of vaccination beyond preventing herpes zoster.

Birth Rate as a Determinant of Dementia Incidence: A Comprehensive Global Analysis.

The role of parity in predicting dementia risk in women is debated. This study examines how birth rate affects global dementia incidence. Country-specific data on birth rate and dementia incidence rate were analyzed using bivariate analysis, partial correlation, and multiple linear regression. Confounding factors such as aging, affluence, genetic predisposition (Ibs), and urbanization were considered. Pearson's r and nonparametric analyzes showed a significant inverse correlation between birth rate and dementia incidence. This relationship remained significant after controlling for aging, affluence, Ibs, and urbanization. Multiple linear regression identified birth rate as a significant predictor of dementia incidence, and as the strongest predictor. Affluence and urbanization were not significant predictors. The correlation was stronger in developing countries. Lower birth rate is an independent risk factor for dementia, particularly in developed countries. These findings highlight the importance of considering birth rate in dementia studies.

Dementia incidence among a cohort of lebanese older adults: first incidence estimates from the Middle East and North Africa region.

To provide the first estimates of dementia incidence rates among elderly in Lebanon. The cohort established in 2013 consisted of 470 elderly from Beirut and Mount Lebanon, who consented to be followed-up. In 2017, we reached 341 participants/informants, achieving a response rate of 72.6%. The validated Arabic version of the 10/66 Dementia Research Group diagnostic tool was administered through face-to-face interviews. Direct age standardization was applied to the data using the Western European population distribution. Age-, sex- and location-specific incidence rates were estimated. After 3.5 years of follow up, 19 new cases of dementia were identified among 229 surviving participants. The crude incidence rate was 16.8 per 1,000 p-y, and the age standardized rate was 20.5 per 1,000 p-y. The incidence rate increased with age, going from 6.5 for those aged 65-74 years to 54.0 for those aged 85-89 years. Incidence rate was higher among females than males (20.7 vs.12.0), and higher in Mount Lebanon, as compared to the capital city Beirut (19.5 vs.14.9). Dementia incidence rate was close to European and North American countries' estimates. The use of validated tools increased the internal validity of our results. A large cohort study is warranted to confirm these results.

ApoE Genotype, Age, and Cognitive Decline in Old Chinese Individuals Without Dementia: A Population-Based Study With Five-Year Follow-Up.

Apolipoprotein E (ApoE) ε4 genotype is a well-known risk factor for Alzheimer's disease (AD). However, its effect on predicting cognitive decline in individuals without dementia and its association with age are unclear. To investigate the relationship between ApoE polymorphism and risk of cognitive decline and dementia incidence in the elderly without dementia. This population-based prospective study was conducted between 2011 and 2016. The study involved 767 dementia-free individuals who had undergone ApoE genotype analysis, were aged ≥ 60years, and lived in rural China. Participants were divided into three ApoE groups: E3 (genotype 3/3), E4 (genotypes 3/4 and 4/4), and E2 (genotype 2/3) groups. After 5years, 666 (86.8%) individuals were followed up. The rate of change in MMSE score was faster in the E4 group than in the E3 and E2 groups (5.0±4.4 vs. 3.5±3.8 vs. 3.9±3.9, p=0.001), after adjusting for age, sex, educational level and baseline MMSE scores, especially in the 70-79years age group. In the same age group, the incidence rate of dementia was higher in the E4 group than in the E3 group (OR=2.850; 95% CI: 1.146-7.090). After adjusting for age, sex, hypertensive status, educational level, marital status, engagement in social activities, and past history of stroke, the ApoE ε4 allele remained an independent risk factor for dementia incidence (OR=3.070; 95% CI: 1.162-8.110) in individuals aged 70-79years after follow-up. ApoE ε4 carriers with age ≥60years had faster cognitive decline. The ApoE ε4 allele was an independent risk factor for dementia incidence in extremely old individuals.

The Protective Role of Ambient Ultraviolet Radiation Against Dementia: An Ecological Analysis of Global Data.

This study investigates the global impact of ambient ultraviolet radiation (UVR) on dementia incidence, addressing its controversial association with dementia risk. UVR, through both vitamin D-dependent and independent mechanisms, influences physiological processes essential for brain health, such as reducing neuroinflammation, improving sleep regulation, and enhancing neuroplasticity. This study aims to clarify the relationship between UVR and dementia incidence and evaluate its role in public health strategies for dementia prevention. An ecological analysis across 204 countries was conducted using country-specific data on UVR levels and dementia incidence rates. Bivariate analysis, partial correlation, and multiple linear regression models were employed to assess the relationship between UVR and dementia incidence. Confounding factors, including aging, economic affluence, genetic predisposition, and urbanization, were controlled to ensure robust results. Subgroup analyses were performed to explore differences across income classifications, regional groupings, and developmental statuses, based on World Bank and United Nations criteria. A significant inverse correlation between UVR and dementia incidence was identified (r = -0.764, p < 0.001), which persisted after adjusting for confounding factors. UVR emerged as the strongest predictor of dementia incidence, explaining a substantial portion of the variance, followed by aging as the second strongest predictor. Subgroup analyses revealed that the protective effects of UVR were particularly pronounced in developing countries, where limited access to vitamin D supplementation, combined with greater exposure tonatural sunlight may enhance its influence. Lower ambient UVR levels are associated with higher dementia incidence rates worldwide, suggesting a critical role for UVR in mitigating dementia risk. Public health strategies should consider environmental factors like UVR, particularly in regions with limited sunlight. Incorporating interventions to optimize UVR exposure could offer a cost-effective approach to reducing the global dementia burden and improving brain health outcomes.

Improving dementia prognostication in cognitively normal older adults: conventional versus novel approaches to modelling risk associated with neuropsychiatric symptoms.

Studies in cognitively normal individuals on associations between psychiatric symptomatology and incident dementia have not reliably differentiated psychiatric syndromes from neuropsychiatric symptoms (NPS) that represent neurodegeneration. Conventional modelling often overlooks symptom natural history. Mild behavioural impairment (MBI) is a syndrome that leverages later-life emergent and persistent NPS to identify a high-risk group for incident dementia. We aimed to explore associations of MBI, and conventionally-measured NPS (NPS-not-MBI), with incident dementia in cognitively normal individuals and the cognitively normal subset with subjective cognitive decline (SCD). Using National Alzheimer's Coordinating Center data, MBI was operationalised by the absence of past psychiatric disorders (symptom emergence) and the presence of symptoms at >2/3 of pre-dementia visits (symptom persistence). Kaplan-Meier survival curves and Cox proportional hazards regressions modelled dementia incidence across NPS groups and MBI domains, adjusted for age, gender, education, race, APOE-ε4, and cognitive status. The sample comprised 1408 MBI (age 75.2 ± 9.5; 54.3% female), 5625 NPS-not-MBI (age 71.6 ± 8.8; 65.5% female) and 5078 No-NPS (age 71.2 ± 8.9; 67.6% female) participants. Compared with No-NPS, MBI participants had lower dementia-free survival (P < 0.0001) and 2.76-fold greater adjusted dementia incidence rate (95% CI: 2.27-3.35, P < 0.001); incidence rate in NPS-not-MBI did not differ from No-NPS (hazard ratio 0.97, 95% CI: 0.82-1.14, P = 0.687). Of those with MBI who progressed to dementia, 76.0% developed Alzheimer's disease. Similarly, in the SCD subsample (n = 3485), persons with MBI had 1.99-fold greater dementia incidence versus No-NPS (95% CI: 1.46-2.71, P < 0.001) while NPS-not-MBI did not differ from No-NPS (hazard ratio 0.92, 95% CI: 0.70-1.19, P = 0.511). Incorporating natural history into assessment of psychiatric symptoms in accordance with MBI criteria enhances dementia prognostication and modelling.

Incidence Rates of Dementia—What Can They Tell Us?

Incidence Rates of Dementia—What Can They Tell Us?

37‐year secular trends in prevalence, incidence, and survival rate of dementia in a Japanese community: the Hisayama Study

37‐year secular trends in prevalence, incidence, and survival rate of dementia in a Japanese community: the Hisayama Study

Temporal Trends in Dementia Incidence in Sweden: Insights from NEAR Data

Abstract Background This study investigates the temporal trends of dementia incidence in Sweden over a span of 35 years, drawing on data from the National E-Infrastructure for Aging Research (NEAR). Methods Our comprehensive analysis encompassed over 10,000 participants aged 50 and above. We estimated dementia incidence rates across the study period, considering birth cohort, age, and sex while controlling for potential confounders. Additionally. We explored potential modifiers influencing the estimated trend of dementia incidence. Results The analysis reveals a notable decline in dementia incidence rates, particularly among individuals born in more recently. Octogenarians born in the 1920-1930 cohort had a 74% lower dementia incidence rate compared to their counterparts born before 1900. Similarly, nonagenarians born in the 1910-1920 cohort experienced a 45% lower incidence rate. We further investigate determinants influencing this declining trend, shedding light on various factors shaping the observed patterns. Conclusions The incidence rate of dementia in Sweden has shown a consistent decline over the past 35 years, with a notable birth cohort effect indicating lower rates among individuals born more recently. This finding suggests evolving factors in lifestyle, healthcare, or environmental conditions contributing to improved cognitive health outcomes. Key Messages • These findings underscore the importance of proactive public health measures aimed at sustaining and enhancing cognitive health outcomes among aging populations. • Understanding the temporal dynamics and underlying factors driving these trends can inform strategies for promoting healthy aging and improving the quality of life for older adults.

Association between preventive treatment for unruptured intracranial aneurysms and incident dementia: a nationwide population-based cohort study

Preventive treatments for unruptured intracranial aneurysms (UIAs) are used worldwide. However, the long-term effects to cognition have been underestimated. Using representative sample data from the National Health Insurance Service-Senior Cohort database, we compared cumulative risk of incident dementia between two groups: (1) treatment versus observation group, and (2) within the treatment group (surgical versus endovascular treatment). Cox proportional hazard ratios were estimated after applying one-to-one propensity score matching. Subgroup analyses were conducted to investigate interactions between treatment effects and sex, age and history of stroke, respectively. After matching, 3,763 participants were included in each group. The 10-year incidence rates of dementia were 9.82 and 8.68 per 1,000 person-years in the treatment and observation groups, respectively (HR: 1.11, 95% CI: 0.90–1.38, P = 0.33). Furthermore, the risk of incident dementia was not different between the surgical and endovascular treatment groups (HR: 0.98, 95% CI: 0.70–1.37, P = 0.91). In the subgroup analysis, surgical treatment was associated with an increased risk of developing dementia, particularly among male patient (HR: 2.34, 95% CI: 1.04–5.28). Preventive treatment of UIAs appears acceptable in terms of long-term effects to cognition. However, further researches are strongly required to identify the high risk patients of development of dementia.

Association between cervical lymph node dissection and dementia: a retrospective analysis

BackgroundDementia, characterized by memory loss and cognitive impairment, considerably impacts individuals and society. Our research focused on cervical lymph nodes, crucial for CNS lymphatic drainage, in the context of dementia. We hypothesized that the patients with head and neck cancer (HNC) undergoing cervical lymph node dissection (CLND) may have increased dementia risk due to obstructed lymphatic pathways. MethodsWe conducted a retrospective analysis of the electronic medical records from patients over 60 years diagnosed with HNC who underwent CLND between March 2007 and April 2023. We collected demographic data, calculated dementia incidence rates, and compared parameters between patients with and without dementia. ResultsAmong the 251 patients with HNC who underwent CLND, 234 were men and 17 were women. Nine male patients developed dementia within an average of 50.1 ± 35.3 months post-surgery. The dementia incidence rate was 0.7 per 100 patient-years, with a cumulative incidence of 10.34% over 8.6 years. The CLND patterns were associated with dementia (p = 0.028), with bilateral supraomohyoid neck dissection (SOHND)/modified radical neck dissection (MRND) and unilateral MRND combined with any neck dissection type on the other side presenting higher risks than unilateral MRND/SOHND (p = 0.016). ConclusionPatients with HNC undergoing bilateral and comprehensive lymph node dissection showed higher dementia risk, highlighting the importance of the neck’s lymphatic role in brain health. These findings may guide future surgical practices.

Tramadol use and incident dementia in older adults with musculoskeletal pain: a population-based retrospective cohort study

We aimed to assess the association of tramadol use with the risk of dementia. This population-based retrospective cohort study using the Korean National Health Insurance Service database included a total of 1,865,827 older adult patients aged 60 years or older with common musculoskeletal pain between January 1, 2003, and December 31, 2007. Individuals who were newly dispensed tramadol (N = 41,963) were identified and propensity score–matched with those who were not (N = 41,963). Over a maximum of 14-year follow-up, the incidence rates (events per 1000 person-years) of all-cause dementia were 6.1 for nonusers, 6.2 for those with cumulative tramadol use of 1–14 days, 7.7 for those with 15–90 days of use, and 8.0 for those with > 90 days of use. Longer cumulative duration of tramadol use was associated with an increased risk of all-cause dementia compared with nonuse (1 to 14 days: aHR 1.06, 95% CI 0.96–1.17; 15 to 90 days: aHR 1.14, 95% CI 1.10–1.35; and more than 90 days: aHR 1.18, 95% CI 1.00–1.39; test for trend: P < 0.001). The results showed a similar pattern for Alzheimer’s disease and were robust across subgroup and sensitivity analyses, but not for vascular dementia. This study found that exposure to tramadol was associated with an increased risk of dementia. Taking this potential risk into consideration, clinicians should carefully weigh potential benefits and risks when prescribing tramadol to older adults with musculoskeletal pain.

Exploring Chronic Pain Patterns and Associations With All-Cause Dementia: Results From UK Biobank

The count of locations with chronic pain is widely used in research and clinical practice. However, this approach might be too simplistic to fully capture the complexity of chronic pain experiences. This study identified prevalent patterns of chronic pain locations and evaluated their associations with incident dementia among middle-aged and older adults in the UK. Data were from 445,530 participants who were free of dementia at baseline (2006–2010) in the UK Biobank. We calculated the incidence rates of all-cause dementia by the 20 most prevalent combinations of pain locations assessed at baseline. Cox models were utilized to examine the hazard ratio of incident dementia among each of these 20 combinations compared to 3 groups: 1) participants without chronic pain, 2) participants with only a single chronic pain location not included in the combination, and 3) participants with only a single chronic pain location included in the combination. The 3 most prevalent combinations were neck and back (5.7%), back and knee (5.4%), and neck and knee (4.5%). Chronic back, neck, and knee pain was commonly present either individually or simultaneously in combinations associated with higher dementia rates than persons without chronic pain. The combinations involving back, neck, and knee were associated with higher dementia rates than groups with 1 pain location not included in the combination. Chronic pain is not randomly present in body locations. Understanding how different patterns of chronic pain locations relate to dementia provides new insights into dementia prevention through pain relief. PerspectiveThis article unveils chronic pain patterns and dementia risks in the UK Biobank. Chronic pain in back, neck, and knee presents frequently, either individually or in combinations associated with increased dementia rates. Chronic pain combos correlate with diverse dementia rates, guiding targeted prevention strategies through pain management.

Association Between Cancer Screening Patterns and Carer Literacy in Individuals With Cognitive Decline: An Observational Study.

The incidence rates of dementia, mild cognitive impairment, and cancer increase with age, posing challenges to affected individuals and their families. However, there are currently no clear cancer screening guidelines for individuals with cognitive impairment. This study analyzed the impact of carer health literacy on screening behaviors in this population. We conducted a postal follow-up survey, associated with the National Center for Geriatrics and Gerontology-Life STORIES of People with Dementia, that targeted primary carers to assess their reports regarding patient attendance at regular cancer screenings recommended by the Japanese Ministry of Health, Labor and Welfare, over the preceding 2 years. Screening rates were compared between the memory clinic cohort and the national average, and the influence of carer health literacy level on screening was analyzed. Among the 826 total individuals analyzed, the memory clinic cohort exhibited lower breast cancer screening rates, at 11% among female patients aged 65-74 years versus the national average of 32%. Higher health literacy among carers was significantly associated with increased screening. For female patients, carers with high levels of communicative health literacy were more likely to ensure that patients attended screenings for gastric (adjusted odds ratio [AOR], 1.77; 95% confidence interval [CI], 1.03-3.04), colorectal (AOR, 1.70, 95% CI 1.08-2.70), and breast cancers (AOR, 3.08; 95% CI, 1.40-6.76). Among the male patients, high communicative health literacy was associated with increased lung cancer screening attendance (AOR, 1.82; 95% CI, 1.11-2.99). Our research highlights a notable gap in cancer screening attendance between individuals with cognitive impairment and the general population, potentially arising from the intricate nature of screening procedures and the extensive burden on carers. More informed decisions and increased screening rates can be achieved through patient-centric communication strategies that accommodate the cognitive abilities of patients, ensuring the comprehensibility and accessibility of health-related information.

Alzheimer Dementia Among Individuals With Down Syndrome

With the advancement in administrative data as a research tool and the reliance on public health insurance for individuals with Down syndrome, population-level trends in Alzheimer dementia in this population are beginning to be understood. To comprehensively describe the epidemiology of Alzheimer dementia in adults with Down syndrome in a full US Medicare and Medicaid sample. This cohort study included 132 720 adults aged 18 years or older with Medicaid and/or Medicare claims data with an International Statistical Classification of Diseases and Related Health Problems code for Down syndrome. Data were collected from January 1, 2011, to December 31, 2019, and analyzed from August 2023 to May 2024. The main outcome was prevalence of Alzheimer dementia in each calendar year and during the 9-year period. Alzheimer dementia incidence rates by calendar year and age and stratified for race or ethnicity as well as time to death after Alzheimer dementia diagnosis were also assessed. There were 132 720 unique adults with Down syndrome from 2011 to 2019: 79 578 (53.2%) were male, 17 090 (11.7%) were non-Hispanic Black, 20 777 (15.7%) were Hispanic, 101 120 (68.8%) were non-Hispanic White, and 47 692 (23.3%) had ever had an Alzheimer dementia diagnosis. Incidence was 22.4 cases per 1000 person-years. The probability of an incident Alzheimer dementia diagnosis over 8 years was 0.63 (95% CI, 0.62-0.64) for those entering the study between ages 55 to 64 years. Mean (SD) age at incident diagnosis was 54.5 (7.4) years and median (IQR) age was 54.6 (9.3) years. Mean (SD) age at death among those with Alzheimer dementia was 59.2 (6.9) years (median [IQR], 59.0 [8.0] years). The mean (SD) age at onset for the Hispanic group was 54.2 (9.2) years, 52.4 (7.8) years for the American Indian or Alaska Native group, and 52.8 (8.2) years for the mixed race groups compared with 55.0 (7.8) years for the White non-Hispanic group. For age at death, there were no differences by sex. The mean (SD) age at death was later for the White non-Hispanic group (59.3 [6.8] years) compared with the Hispanic group (58.5 [7.8] years), Native American group (57.8 [7.1] years), and mixed race group (58.2 [7.0] years). In this cohort study of adults with Down syndrome who were enrolled in Medicaid and Medicare, Alzheimer dementia occurred at high rates. Consistency with clinical studies of dementia in Down syndrome supports the use of administrative data in Down syndrome-Alzheimer dementia research.

Associations between tooth loss, denture use, and dementia in older Taiwanese adults.

The literature has mainly focused on the association between tooth loss and dementia, and evidence regarding the separate and joint effects of tooth loss and denture use on the risk of dementia is limited. This study investigated the links among tooth loss, denture use, and dementia risk in Taiwanese adults aged 65 years or older. This retrospective cohort study utilized data from the 2009 National Health Interview Survey and 2008-2017 National Health Insurance claim records, including the records of 2247 individuals free from dementia treatment in 2008-2009. Dementia diagnoses were tracked until 2017. The Cox proportional hazards model was used to calculate hazard ratios (HRs) for exploring the correlations among tooth loss, denture use, and dementia risk. Older adults with 20 or more natural teeth and dentures had the lowest dementia incidence (1.43 per 100 person-years). Those with <20 natural teeth, with or without dentures, experienced high dementia incidence rates of 2.31 and 3.33 per 100 person-years, respectively. After adjusting for various factors (i.e., sociodemographic characteristics, health conditions/comorbidities, and lifestyles), having <20 natural teeth or not using dentures was associated with non-significantly increased HRs of 1.30 (95% CI, 0.99-1.71) and 1.20 (95% CI, 0.95-1.52). Subgroup analysis revealed that compared to older adults with 20 or more natural teeth and dentures, those with <20 natural teeth and not wearing dentures had a significantly increased risk of dementia (adjusted HR, 1.57; 95% CI, 1.04-2.37). This study found that having <20 natural teeth and not using dentures was significantly associated with an increased risk of dementia in Taiwanese individuals aged 65 years or above.

Cervical cancer and risk of dementia: real-world insights from a nationwide cohort study in Taiwan

ObjectiveCervical cancer, linked to human papillomavirus (HPV), ranks fourth among women’s cancers globally. Several studies have found an association between viral infections or cancer and dementia, which is a major...

Association of Gum Treatment with Cognitive Decline and Dementia Risk among Older Adults with Periodontal Symptoms: A 12-Year Prospective Cohort Study.

This study examines the associations of gum treatment with cognitive decline and dementia risk among older adults with periodontal symptoms in the USA. A cohort of 866 adults aged ≥50 with periodontal symptoms was recruited for the 2008 Health and Retirement Study "Dental Health Experimental Module" and followed until 2020. Cognitive function was assessed with the Telephone Interview for Cognitive Status (TICS). Dementia status was ascertained with the Langa-Weir algorithm based on TICS scores and proxy assessments. Linear mixed-effects model and multivariable Cox regression models were utilized to analyze the associations of gum treatment with cognitive decline and the risk of dementia, respectively. Of 866 participants (mean age 67.7, 61.4% women), 105 (12.1%) developed dementia with a median follow-up of 9 (IQR, 6-10) years. The dementia incidence rates were lower in the group with gum treatment (7.4 vs. 12.9 per 1,000 person-years). Compared with participants who did not have gum treatment, those with gum treatment experienced a decline in TICS score that was on average 0.025 (95% CI, 0.005-0.044) points less per year and a 38% lower incidence of dementia (hazard ratio, 0.62; 95% CI, 0.41-0.93). These associations were consistent across participants with a different severity of periodontal symptoms and sociodemographic characteristics (age, sex, race, ethnicity, and education) except for income levels. Prompt gum treatment for older adults with periodontal symptoms may be beneficial for their cognitive health.

Estimating dementia incidence in insured older Asian Americans and Pacific Islanders in California: an application of inverse odds of selection weights.

Literature shows heterogeneous age-standardized dementia incidence rates across US Asian American, Native Hawaiian, and Pacific Islanders (AANHPI), but no estimates of population-representative dementia incidence exist due to lack of AANHPI longitudinal probability samples. We compared harmonized characteristics between AANHPI Kaiser Permanente Northern California members (KPNC cohort) and the target population of AANHPI 60+ with private or Medicare insurance using the California Health Interview Survey. We used stabilized inverse odds of selection weights (sIOSW) to estimate ethnicity-specific crude and age-standardized dementia incidence rates and cumulative risk by age 90 in the target population. Differences between the KPNC cohort and target population varied by ethnicity. sIOSW eliminated most differences in larger ethnic groups; some differences remained in smaller groups. Estimated crude dementia incidence rates using sIOSW (versus unweighted) were similar in Chinese, Filipinos, Pacific Islanders and Vietnamese, and higher in Japanese, Koreans, and South Asians. Unweighted and weighted age-standardized incidence rates differed for South Asians. Unweighted and weighted cumulative risk were similar for all groups. We estimated the first population-representative dementia incidence rates and cumulative risk in AANHPI ethnic groups. We encountered some estimation problems and weighted estimates were imprecise, highlighting challenges using weighting to extend inferences to target populations.

The criteria used to rule out mild cognitive impairment impact dementia incidence rates in subjective cognitive decline

BackgroundThe research criteria for subjective cognitive decline (SCD) exclude mild cognitive impairment (MCI), but do not stipulate the use of specific MCI criteria. This study compared different approaches to defining (i.e., excluding) MCI during the ascertainment of SCD, focusing on the impact on dementia incidence rates in SCD.MethodsThis cohort study utilized routine healthcare data collected in the Essex Memory Clinic from 1999 to 2023. Two different operationalizations of the SCD criteria were used to categorize the cohort into two SCD patient samples. One sample was based on local clinical practice – MCI was excluded according to the Winblad criteria (this sample was termed SCDWinblad). The other sample was created via the retrospective application of the Jak/Bondi criteria for the exclusion of MCI (termed SCDJak/Bondi). Only patients aged ≥ 55 years at baseline with ≥ 12 months follow-up were considered for inclusion. The initial clinical/demographic characteristics of the samples were compared. Rates of incident dementia were calculated for each sample, and unadjusted and Mantel-Haenszel-adjusted incidence rate ratios were calculated to compare dementia incidence between the SCD samples.ResultsThe Essex Memory Clinic database included 2,233 patients in total. The SCD and study eligibility criteria were used to select SCDWinblad (n = 86) and SCDJak/Bondi (n = 185) samples from the database. Median follow-up (3 years) did not differ between the two samples. The SCDJak/Bondi sample was significantly older than the SCDWinblad at first assessment (median age: 74 versus 70 years) and had poorer scores on tests of global cognition, immediate and delayed verbal recall, and category fluency. Following adjustment for age, the dementia incidence rate ratio [95% confidence interval] was 3.7 [1.5 to 9.3], indicating a significantly greater rate of progression to dementia in SCDJak/Bondi.ConclusionsThis study highlights that the approach used to ascertain SCD has important implications for both SCD phenotypes and prognosis. This underscores the importance of how MCI is operationalized within SCD studies. More broadly, the findings add to a growing body of work indicating that objective cognition should not be overlooked in SCD, and offer a potential explanation for the heterogeneity across the SCD prognostic literature.