Pushpani Herath

Development of a new method for assessing global risk of alzheimer's disease for use in population health approaches to prevention

Alzheimer’s disease (AD) affects approximately 35 million people worldwide. Increasing evidence suggests that many risk factors for AD are modifiable. AD pathology develops over decades. Hence risk reduction interventions require very long follow-ups to show effects on AD incidence. Focussing on AD risk, instead of diagnosis, provides a more realistic target for prevention strategies. We developed a novel methodology that yields a global approach to risk assessment for AD for use in population-based settings and interventions. The methodology was used to develop a risk assessment tool that can be updated as more evidence becomes available. First, a systematic search strategy identified risk and protective factors for AD. Eleven risk factors and four protective factors for AD were identified for which odds ratios were published or could be calculated (age, sex, education, body mass index, diabetes, depression, serum cholesterol, traumatic brain injury, smoking, alcohol intake, social engagement, physical activity, cognitive activity, fish intake, and pesticide exposure). An algorithm was developed to combine the odds ratios into an AD risk score. The approach allows for interactions among risk factors which provides for their varying impact over the life-course as current evidence suggests midlife is a critical period for some risk factors. Finally, a questionnaire was developed to assess the risk and protective factors by self-report. Compared with developing risk indices on single cohort studies, this approach allows for more risk factors to be included, greater generalizeability of results, and incorporation of interactions based on findings from different stages of the lifecourse.

A Self-Report Risk Index to Predict Occurrence of Dementia in Three Independent Cohorts of Older Adults : The ANU-ADRI

Background and Aims The Australian National University AD Risk Index (ANU-ADRI, http://anuadri.anu.edu.au) is a self-report risk index developed using an evidence-based medicine approach to measure risk of Alzheimers disease (AD). We aimed to evaluate the extent to which the ANU-ADRI can predict the risk of AD in older adults and to compare the ANU-ADRI to the dementia risk index developed from the Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study for middle-aged cohorts. Methods This study included three validation cohorts, i.e., the Rush Memory and Aging Study (MAP) (n = 903, age ≥53 years), the Kungsholmen Project (KP) (n = 905, age ≥75 years), and the Cardiovascular Health Cognition Study (CVHS) (n = 2496, age ≥65 years) that were each followed for dementia. Baseline data were collected on exposure to the 15 risk factors included in the ANU-ADRI of which MAP had 10, KP had 8 and CVHS had 9. Risk scores and C-statistics were computed for individual participants for the ANU-ADRI and the CAIDE index. Results For the ANU-ADRI using available data, the MAP study c-statistic was 0·637 (95% CI 0·596–0·678), for the KP study it was 0·740 (0·712–0·768) and for the CVHS it was 0·733 (0·691–0·776) for predicting AD. When a common set of risk and protective factors were used c-statistics were 0.689 (95% CI 0.650–0.727), 0.666 (0.628–0.704) and 0.734 (0.707–0.761) for MAP, KP and CVHS respectively. Results for CAIDE ranged from c-statistics of 0.488 (0.427–0.554) to 0.595 (0.565–0.625). Conclusion A composite risk score derived from the ANU-ADRI weights including 8–10 risk or protective factors is a valid, self-report tool to identify those at risk of AD and dementia. The accuracy can be further improved in studies including more risk factors and younger cohorts with long-term follow-up.

Multimorbidity is associated with higher out-of-pocket spending: a study of older Australians with multiple chronic conditions

Most older Australians have at least one chronic health condition. The management of chronic disease is associated with potentially severe economic consequences for patients and their households, partially due to the financial burden associated with out-of-pocket costs for medical and health-related care. A questionnaire was mailed to a cross-sectional sample of older Australians in mid-2009, with 4574 responding. Multivariate logistic regression models were developed to investigate the relationships between multimorbidity and out-of-pocket spending on medical and health-related expenses, including the factors associated with severe financial stress among older Australians. We found a positive relationship between number of chronic conditions and out-of-pocket spending on health and that people with multiple chronic conditions tend to be on lower incomes. People with five or more chronic conditions spent on average five times as much on their health as those with no diagnosed chronic conditions and each additional chronic disease added 46% to the likelihood of a person facing a severe financial burden due to health costs.

A 12-week multidomain intervention versus active control to reduce risk of Alzheimer’s disease: study protocol for a randomized controlled trial

BackgroundDisappointing results from clinical trials of disease-modifying interventions for Alzheimer’s dementia (AD), along with reliable identification of modifiable risk factors in mid life from epidemiological studies, have contributed to calls to invest in risk-reduction interventions. It is also well known that AD-related pathological processes begin more than a decade before the development of clinical signs. These observations suggest that lifestyle interventions might be most effective when targeting non-symptomatic adults at risk of AD. To date, however, the few dementia risk-reduction programs available have targeted individual risk factors and/or were restricted to clinical settings. The current study describes the development of an evidence-based, theoretically-driven multidomain intervention to reduce AD risk in adults at risk.MethodThe design of Body Brain Life (BBL) is a randomized controlled trial (RCT) to evaluate a 12-week online AD risk-reduction intervention. Eligible participants with several modifiable risk factors on the Australian National University (ANU) AD Risk Index (ANU-ADRI) are randomly allocated to an online only group, an online and face-to-face group, or an active control group. We aim to recruit 180 participants, to undergo a comprehensive cognitive and physical assessment at baseline, post-intervention, and 6-month follow-up assessment. The intervention comprises seven online modules (dementia literacy, risk factor education, engagement in physical, social, and cognitive lifestyles, nutrition, and health monitoring) designed using contemporary models of health behavior change.DiscussionThe BBL program is a novel online intervention to reduce the risk of AD in middle-aged adults at risk. The trial is currently under way. It is hypothesized that participants in the intervention arms will make lifestyle changes in several domains, and that this will lead to a reduction in their AD risk profile. We also expect to show that health behavior change is underpinned by changes in psychological determinants of behavior. If successful, the findings will contribute to the development of further dementia risk reduction interventions, and thus contribute to the urgent need to lower dementia risk factors in the population to alter future projections of disease prevalence. Longer follow-up of BBL participants and replications using large samples are required to examine whether reduction in AD risk factors will be associated with reduced prevalence.Trial registrationReg. no. ACTRN12612000147886

The impact of chronic illness on workforce participation and the need for assistance with household tasks and personal care by older Australians

People, along with their families, feel the impact of chronic illness in many areas of their lives. It has been known that those with chronic illness leave the workforce earlier than their peers, have lower incomes and often need additional support to manage their health and lives. However, limited information is available about whether chronic illness is already present prior to retirement, or has developed subsequently. Similarly, we know little about what personal and household assistance is needed by people with chronic illness. In this study, a random sample of 10 000 members of National Seniors Australia, stratified by age and state of residence, were surveyed by post between August and September 2009 and asked about their chronic illnesses along with their age at diagnosis. In addition, participants were asked about their need for assistance with everyday household tasks and personal care. Responses were received from 4574 respondents, a response rate of 45.7%. Of those responding, 82.2% reported having at least one chronic illness at the time of the survey. The study confirms that ill health leads to earlier retirement from the workforce, and those who are sickest require more assistance with their household tasks and personal care. Each additional chronic illness present at age 50 reduced working life by a year, and each present at age 60 by 0.7 years. Diabetes, arthritis and depression were significantly related to earlier retirement. The impact was greatest for both continued workforce participation and need for assistance for those suffering from depression or anxiety. The relationships between health, workforce participation and need for assistance in daily activities are complex. Further research is required to uncover this complexity; nevertheless, the findings highlight the need to review the adequacy of current social and health policy for this particular population.

The Effect of Diabetes Medication on Cognitive Function: Evidence from the PATH Through Life Study

Objective. To examine the effect of diabetes treatment on change of measures of specific cognitive domains over 4 years. Research Design and Methods. The sample was drawn from a population-based cohort study in Australia (the PATH Through Life Study) and comprised 1814 individuals aged 65–69 years at first measurement, of whom 211 were diagnosed with diabetes. Cognitive function was measured using 10 neuropsychological tests. The effect of type of diabetes treatment (diet, oral hypoglycemic agents, and insulin) on measures of specific cognitive domains was assessed using Generalized Linear Models adjusted for age, sex, education, smoking, physical activity level, BMI, and hypertension. Results. Comparison of cognitive function between diabetes treatment groups showed no significant effect of type of pharmacological treatment on cognitive function compared to diet only group or no diabetes group. Of those on oral hypoglycaemic treatment only, participants who used metformin alone had better cognitive function at baseline for the domains of verbal learning, working memory, and executive function compared to participants on other forms of diabetic treatment. Conclusion. This study did not observe significant effect from type of pharmacological treatment for diabetes on cognitive function except that participants who only used metformin showed significant protective effect from metformin on domain of verbal learning, working memory, and executive function.

Body brain life: A randomized controlled trial of an online dementia risk reduction intervention in middle-aged adults at risk of Alzheimer's disease

To examine the efficacy of body brain life (BBL), a 12‐week online dementia risk reduction intervention.