Have We Been Underestimating Modifiable Dementia Risk? An Alternative Approach for Calculating the Combined Population Attributable Fraction for Modifiable Dementia Risk Factors.

Estimating the fraction of dementia cases in a population attributable to a risk factor or combination of risk factors (the population attributable fraction (PAF)) informs the design and choice of dementia risk-reduction activities. It is directly relevant to dementia prevention policy and practice. Current methods employed widely in the dementia literature to combine PAFs for multiple dementia risk factors assume a multiplicative relationship between factors and rely on subjective criteria to develop weightings for risk factors. In this paper we present an alternative approach to calculating the PAF based on sums of individual risk. It incorporates individual risk factor interrelationships and enables a range of assumptions about the way in which multiple risk factors will combine to affect dementia risk. Applying this method to global data demonstrates that the previous estimate of 40% is potentially too conservative an estimate of modifiable dementia risk and would necessitate subadditive interaction between risk factors. We calculate a plausible conservative estimate of 55.7% (95% confidence interval: 55.2, 56.1) based on additive risk factor interaction.

Psychotropic medicine prescribing and polypharmacy for people with dementia entering residential aged care: the influence of changing general practitioners.

OBJECTIVE: To examine relationships between changing general practitioner after entering residential aged care and overall medicines prescribing (including polypharmacy) and that of psychotropic medicines in particular. DESIGN: Retrospective data linkage study. SETTING, PARTICIPANTS: 45 and Up Study participants in New South Wales with dementia who were PBS concession card holders and entered permanent residential aged care during January 2010 - June 2014 and were alive six months after entry. MAIN OUTCOME MEASURES: Inverse probability of treatment-weighted numbers of medicines dispensed to residents and proportions of residents dispensed antipsychotics, benzodiazepines, and antidepressants in the six months after residential care entry, by most frequent residential care GP category: usual (same as during two years preceding entry), known (another GP, but known to the resident), or new GP. RESULTS: Of 2250 new residents with dementia (mean age, 84.1 years; SD, 7.0 years; 1236 women [55%]), 625 most frequently saw their usual GPs (28%), 645 saw known GPs (29%), and 980 saw new GPs (44%). The increase in mean number of dispensed medicines after residential care entry was larger for residents with new GPs (+1.6 medicines; 95% CI, 1.4-1.9 medicines) than for those attended by their usual GPs (+0.7 medicines; 95% CI, 0.4-1.1 medicines; adjusted rate ratio, 2.42; 95% CI, 1.59-3.70). The odds of being dispensed antipsychotics (adjusted odds ratio [aOR], 1.59; 95% CI, 1.18-2.12) or benzodiazepines (aOR, 1.69; 95% CI, 1.25-2.30), but not antidepressants (aOR, 1.32; 95% CI, 0.98-1.77), were also higher for the new GP group. Differences between the known and usual GP groups were not statistically significant. CONCLUSIONS: Increases in medicine use and rates of psychotropic dispensing were higher for people with dementia who changed GP when they entered residential care. Facilitating continuity of GP care for new residents and more structured transfer of GP care may prevent potentially inappropriate initiation of psychotropic medicines.

The impact of dementia on aged care service transitions in the last five years of life.

OBJECTIVE: To investigate the impact of dementia on aged care service use at end-of-life. METHODS: Our retrospective data linkage study in New South Wales, Australia, used survey data from participants in the 45 and Up Study who died between July 2011-June 2014 linked to routinely collected administrative data for 2006-2014. We investigated movement between aged care "states" (No Services, Home Care including Home Support and Low-and High-Level Home Care and Residential Care) in the last five years of life. The dementia cohort comprised decedents with a dementia diagnosis recorded in hospital records, death certificates or who had claims for dementia-specific medicines prior to death (n = 2,230). The comparison cohort were decedents with no dementia diagnosis, matched 1:1 on age-at-death, sex, income and location. RESULTS: Compared to those without dementia, people with dementia were more likely to: use home care (67 versus 60%, P < 0.001), enter residential care (72 versus 30%, P < 0.001) and stay longer in residential care (median 17.9 versus 12.7 months, P < 0.001). Five years before death, more people with dementia were within residential care (6 versus 4%; RR = 1.61, 95%CI = 1.23-2.10) and these rates diverged at the end-of-life (69 versus 28%, RR = 2.48, 95%CI = 2.30-2.66). Use of home-based care was higher among people with dementia five years from death (20 versus 17%; RR = 1.15, 95%CI = 1.02-1.30) but lower at end-of-life (13 versus 24%, RR = 0.55, 95%CI = 0.49-0.63). CONCLUSION: Dementia-specific aged care trajectories were dominated by residential care. Home care use declined towards end-of-life for people with dementia and may not be meeting their needs.

Factors Associated with Participation in a Multidomain Web-Based Dementia Prevention Trial: Evidence from Maintain Your Brain (MYB).

BACKGROUND: The Maintain Your Brain (MYB) trial aims to prevent cognitive decline and dementia through multidomain, web-based risk-reduction. To facilitate translation, it is important to understand drivers of participation. OBJECTIVE: To describe characteristics associated with participation in MYB. METHODS: This was an observational ancillary study of MYB, a randomized controlled trial nested within the 45 and Up Study in New South Wales, Australia. We linked 45 and Up Study survey and MYB participation data. The study cohort comprised 45 and Up Study participants, aged 55-77 years at 1 January 2018, who were invited to participate in MYB. 45 and Up Study participant characteristics and subsequent MYB consent and participation were examined. RESULTS: Of 98,836 invited, 13,882 (14%) consented to participate and 6,190 participated (6%). Adjusting for age and sex, a wide range of factors were related to participation. Higher educational attainment had the strongest relationship with increased MYB participation (university versus school non-completion; AdjOR = 5.15; 95% CI:4.70-5.64) and lower self-rated quality of life with reduced participation (Poor versus Excellent: AdjOR = 0.19; 95% CI:0.11-0.32). A family history of Alzheimer's disease was related to increased participation but most other dementia risk factors such as diabetes, obesity, stroke, high blood pressure, and current smoking were associated with reduced participation. CONCLUSION: Higher socio-economic status, particularly educational attainment, is strongly associated with engagement in online dementia prevention research. Increasing population awareness of dementia risk factors, and better understanding the participation barriers in at-risk groups, is necessary to ensure online interventions are optimally designed to promote maximum participation.

Measuring dementia incidence within a cohort of 267,153 older Australians using routinely collected linked administrative data.

To estimate dementia incidence rates using Australian administrative datasets and compare the characteristics of people identified with dementia across different datasets. This data linkage study used a cohort of 267,153 from the Australian 45 and Up Study. Participants completed a survey in 2006-2009 and subsequent dementia was identified through pharmaceutical claims, hospitalisations, aged care eligibility assessments, care needs at residential aged care entry and death certificates. Age-specific, and age-standardised incidence rates, incidence rate ratios and survival from first dementia diagnosis were estimated. Estimated age-standardised dementia incidence rates using all linked datasets was 16.8 cases per 1000 person years for people aged 65+. Comparing incidence rates to the global published rates suggested 77% of cases were identified but this varied by age with highest coverage among those aged 80-84 years (92%). Incidence rate ratios were inconsistent across datasets for: sex, socio-economic disadvantage, size of support network, marital status, functional limitations and diabetes. Median survival from first dementia diagnosis ranged from 1.80 years in the care needs dataset to 3.74 years in the pharmaceutical claims dataset. Characteristics of people identified with dementia in different administrative datasets reflect the factors that drive interaction with specific services; this may introduce bias in observational studies using a single data-source to identify dementia.

Impact of Prior Home Care on Length of Stay in Residential Care for Australians With Dementia.

OBJECTIVES: To assess the impact of home care on length-of-stay within residential care. DESIGN: A retrospective observational data-linkage study. SETTING AND PARTICIPANTS: In total there were 3151 participants from the 45 and Up Study in New South Wales, Australia with dementia who entered residential care between 2010 and 2014. METHODS: Survey data collected from 2006‒2009 were linked to administrative data for 2006‒2016. The highest level of home care a person accessed prior to residential care was defined as no home care, home support, low-level home care, and high-level home care. Multinomial logistic regression and Cox proportional hazards were used to investigate differences in activities of daily living, behavioral, and complex healthcare scales at entering residential care; and length-of-stay in residential care. RESULTS: People with prior high-level home care entered residential care needing higher assistance compared with the no home care group: activities of daily living [odds ratio (OR) 3.41, 95% confidence interval (CI) 2.14‒5.44], behavior (OR 2.61, 95% CI 1.69‒4.03), and complex healthcare (OR 2.02, 95% CI 1.06‒3.84). They had a higher death rate, meaning shorter length-of-stay in residential care (<2 years after entry: hazard ratio 1.12; 95% CI 0.89‒1.42; 2-4 years: hazard ratio 1.49; 95% CI 1.01‒2.21). Those using low-level home care were less likely to enter residential care needing high assistance compared to the no home care group (activities of daily living: OR 0.61, 95% CI 0.45‒0.81; behavioral: OR 0.72, 95% CI 0.54‒0.95; complex healthcare: OR 0.51, 95% CI 0.33‒0.77). There was no difference between the home support and no home care groups. CONCLUSIONS: High-level home care prior to residential care may help those with dementia stay at home for longer, but the low-level care group entered residential care at low assistance levels, possibly signaling lack of informal care and barriers in accessing higher-level home care. IMPLICATIONS: Better transition options from low-level home care, including more timely availability of high-level care packages, may help people with dementia remain at home longer.