Prevalence and Determinants of Diagnosed Dementia: A Registry Linkage Study Linking Diagnosis of Dementia in the Population-Based HUNT Study to Registry Diagnosis of Dementia in Primary Care and Hospitals in Norway.

Background: A timely diagnosis of dementia can be beneficial for providing good support, treatment, and care, but the diagnostic rate remains unknown and is probably low. Objective: To determine the dementia diagnostic rate and to describe factors associated with diagnosed dementia. Methods: This registry linkage study linked information on research-based study diagnoses of all-cause dementia and subtypes of dementias, Alzheimer's disease, and related dementias, in 1,525 participants from a cross-sectional population-based study (HUNT4 70+) to dementia registry diagnoses in both primary-care and hospital registries. Factors associated with dementia were analyzed with multiple logistic regression. Results: Among those with research-based dementia study diagnoses in HUNT4 70+, 35.6% had a dementia registry diagnosis in the health registries. The diagnostic rate in registry diagnoses was 19.8% among home-dwellers and 66.0% among nursing home residents. Of those with a study diagnosis of Alzheimer's disease, 35.8% (95% confidence interval (CI) 32.6-39.0) had a registry diagnosis; for those with a study diagnosis of vascular dementia, the rate was 25.8% (95% CI 19.2-33.3) and for Lewy body dementias and frontotemporal dementia, the diagnosis rate was 63.0% (95% CI 48.7-75.7) and 60.0% (95% CI 43.3-75.1), respectively. Factors associated with having a registry diagnosis included dementia in the family, not being in the youngest or oldest age group, higher education, more severe cognitive decline, and greater need for help with activities of daily living. Conclusions: Undiagnosed dementia is common, as only one-third of those with dementia are diagnosed. Diagnoses appear to be made at a late stage of dementia.

A longitudinal cohort study on the use of health and care services by older adults living at home with/without dementia before and during the COVID-19 pandemic: the HUNT study.

BACKGROUND: Older adults and people with dementia were anticipated to be particularly unable to use health and care services during the lockdown period following the COVID-19 pandemic. To better prepare for future pandemics, we aimed to investigate whether the use of health and care services changed during the pandemic and whether those at older ages and/or dementia experienced a higher degree of change than that observed by their counterparts. METHODS: Data from the Norwegian Trøndelag Health Study (HUNT4 70 + , 2017-2019) were linked to two national health registries that have individual-level data on the use of primary and specialist health and care services. A multilevel mixed-effects linear regression model was used to calculate changes in the use of services from 18 months before the lockdown, (12 March 2020) to 18 months after the lockdown. RESULTS: The study sample included 10,607 participants, 54% were women and 11% had dementia. The mean age was 76 years (SD: 5.7, range: 68-102 years). A decrease in primary health and care service use, except for contact with general practitioners (GPs), was observed during the lockdown period for people with dementia (p < 0.001) and those aged ≥ 80 years without dementia (p = 0.006), compared to the 6-month period before the lockdown. The use of specialist health services decreased during the lockdown period for all groups (p ≤ 0.011), except for those aged < 80 years with dementia. Service use reached levels comparable to pre-pandemic data within one year after the lockdown. CONCLUSION: Older adults experienced an immediate reduction in the use of health and care services, other than GP contacts, during the first wave of the COVID-19 pandemic. Within primary care services, people with dementia demonstrated a more pronounced reduction than that observed in people without dementia; otherwise, the variations related to age and dementia status were small. Both groups returned to services levels similar to those during the pre-pandemic period within one year after the lockdown. The increase in GP contacts may indicate a need to reallocate resources to primary health services during future pandemics. TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov, with the identification number NCT04792086.

Spousal bereavement and its effects on later life physical and cognitive capability: the Tromsø study.

Spousal bereavement is associated with health declines and increased mortality risk, but its specific impact on physical and cognitive capabilities is less studied. A historical cohort study design was applied including married Tromsø study participants (N=5739) aged 50-70 years with baseline self-reported overall health and health-related factors and measured capability (grip strength, finger tapping, digit symbol coding, and short-term recall) at follow-up. Participants had data from Tromsø4 (1994-1995) and Tromsø5 (2001), or Tromsø6 (2007-2008) and Tromsø7 (2015-2016). Propensity score matching, adjusted for baseline confounders (and baseline capability in a subset), was used to investigate whether spousal bereavement was associated with poorer subsequent capability. Spousal bereavement occurred for 6.2% on average 3.7 years (SD 2.0) before the capability assessment. There were no significant bereavement effects on subsequent grip strength, immediate recall, or finger-tapping speed. Without adjustment for baseline digit symbol coding test performance, there was a negative significant effect on the digit symbol coding test (ATT -1.33; 95% confidence interval -2.57, -0.10), but when baseline digit symbol coding test performance was taken into account in a smaller subsample, using the same set of matching confounders, there was no longer any association (in the subsample ATT changed from -1.29 (95% CI -3.38, 0.80) to -0.04 (95% CI -1.83, 1.75). The results in our study suggest that spousal bereavement does not have long-term effects on the intrinsic capacity components physical or cognition capability to a notable degree.

Health-promoting behaviors in older adulthood and intrinsic capacity 10 years later: the HUNT study.

BACKGROUND: With the global population growing older, there is a need for more knowledge of how to improve and/or maintain functional capacities to promote healthy ageing. In this study we aimed to assess the effect of several known health-promoting behaviors in old age with intrinsic capacity ten years later. METHODS: This was a prospective cohort study looking at participants that were ≥ 65 years at the time of the third wave of the Trøndelag Health Study (HUNT3, 2006-2008) who also took part in the 70 + sub-study of the fourth wave (HUNT4 70+, 2017-2019). Self-reported behavior data from short questionnaires, including diet and physical activity, were collected in HUNT3, and data on the five domains of intrinsic capacity defined by the World Health Organization were collected in HUNT4 70+. A composite index was created for both healthy life and intrinsic capacity, awarding points for how well participants adhered to guidelines for healthy living and their level of functional impairment, respectively. Ordinal logistic regression was used to assess the relationship between health-promoting behaviors and intrinsic capacity. RESULTS: Of 12,361 participants in HUNT3 ≥ 65 years, 4699 (56.5% women) also participated in HUNT4 70+. On the health-promoting behaviors, lowest adherence to healthy living guidelines were seen for fruit and vegetables intake (47.2%), milk intake (46.7%) and physical activity (31.1%). On intrinsic capacity domains, highest impairment was seen in the domains of locomotion (29.7%), hearing (11.1%) and vitality (8.3%). A higher adherence to guidelines for healthy living was associated with higher intrinsic capacity 10 years later. A one-point increase in the healthy life index was associated with a 1.15 (95% confidence interval 1.10-1.21) times increased odds of being in a higher intrinsic capacity category. CONCLUSION: Health-promoting behaviors in old age are associated with better intrinsic capacity ten years later. In clinical settings assessment of health-promoting behaviors could potentially be done using short questionnaires.

Hearing impairment and risk of dementia in The HUNT Study (HUNT4 70+): a Norwegian cohort study.

Background: Hearing impairment is strongly associated with future dementia. No studies have reported objectively measured hearing impairment in a cohort with a long period of follow-up (>20 years), and few have reported follow-up over 10 years. Hence, there is a need for high quality studies with sufficient follow-up time and data to account for reverse causality and confounding. We aimed to address this knowledge gap. Methods: This cohort study used individual participant data from The Trøndelag Health Study (HUNT) in Norway. All current residents aged at least 20 years in the former Norwegian Nord-Trøndelag County were invited to participate in four decennial surveys: HUNT1 (1984-1986), HUNT2 (1995-1997), HUNT3 (2006-2008), and HUNT4 (2017-2019) with individuals aged at least 70 years included in a substudy, known as HUNT4 70+. Here, we report the findings of this substudy. HUNT4 70+ comprised 7135 participants who were assessed for dementia using the Diagnostic and Statistical Manual of Mental Disorders 5 criteria and who had audiometry between 1996 and 1998. The primary objective was to investigate, with gold standard audiometric testing and dementia diagnostic assessment, whether hearing impairment was an independent risk factor for all-cause dementia. The secondary objective was to investigate if a risk also applied to Alzheimer dementia and non-Alzheimer dementia. We analysed the association using Poisson regression and adjusted for confounders. This study is registered with ClinicalTrials.gov (NCT04284384). Findings: At baseline, 1058 (15%) individuals had acquired hearing impairment with a hearing threshold of at least 25 decibel (dB) and, at follow-up, 1089 (15%) had dementia. In the total group, people with hearing impairment had a relative risk (RR) 1.04 (95% confidence interval (CI) 1.00-1.09) per 10 dB increase in hearing thresholds. For individuals younger than 85 years at follow-up the RR was 1.12 (95% CI 1.05-1.21). Associations between hearing impairment and Alzheimer dementia and non-Alzheimer dementia were similar. There was no association for individuals aged at least 85 years. Interpretation: We found a moderate association between objectively measured hearing impairment and dementia in the younger age group (<85 years). The findings of no association in the older age group (≥85 years) might be due to the competing risk of death. The present study adds to the literature showing that acquired hearing impairment is a risk for dementias over a period which is too long for reverse causation, and with thorough consideration of confounders. Further research is needed to investigate associations between the different aetiologies of hearing loss and dementia subtypes, and risk differences for sexes. Funding: The Norwegian National Centre for Ageing and Health with a grant from Health South-East.