Stroke In Older People Research Articles

Stroke Characteristics in the Elderly: A Hospital-Based Study in Cameroon.

Advanced age is an important nonmodifiable risk factor for stroke. Little data are available on stroke in older people in sub-Saharan Africa. This study aimed to determine the clinical features of stroke and identify the predictive factors for poor outcomes in this age group. A 4-month retrospective study was conducted using the Stroke Registry of Douala General Hospital. The main outcomes were mortality, poor functional recovery at 3 months (modified Rankin Scale score ≥3), and recurrence at 1 year. Factors associated with poor outcomes were determined using binary logistic regression. Survival was estimated using the Kaplan-Meier method. The significance threshold was set at p < 0.05. Elderly patients represented 38.6% of all stroke cases (n = 1,260). Male represented 48.6% of the old patients. The incidence of hypertension, diabetes, previous stroke, and cardiopathies was significantly higher in older patients (p < 0.05). Ischemic stroke accounted for 73.1% of stroke types. Cardiopathies, GCS 8-12, GCS <8, hemorrhagic stroke, NIHSS >14, and Barthel index at 1 month were independently associated with mortality. Being divorced, a modified Rankin scale score ≥3 at 1 month, and a Barthel index ≤60 at 1 month were independently associated with poor functional recovery at 3 months. Old patients represented 50% of recurrent stroke cases. Age >90 years (p < 0.001) and NIHSS <5 were independently associated to recurrence at 1 year. Approximately two out of five stroke cases were old. Cardiopathies, hemorrhagic stroke, and data related to stroke severity contribute to poor outcomes. A management approach that considers the particularities of this age group could contribute to improving the outcomes of these patients.

Association between late-life depression or depressive symptoms and stroke morbidity in elders: A systematic review and meta-analysis of cohort studies.

Whether late-life depression or depressive symptoms are a risk factor of future stroke in elders is important for prevention measures. A systematic review and meta-analysis were used to investigate the association between depression or depressive symptoms and risk of stroke in elders. Embase, MEDLINE, PsychINFO, and Web of Science were searched for studies published from inception to January 6, 2023. Prospective cohort studies reporting quantitative estimates of the association between depression or depressive symptoms and stroke morbidity in participants aged over 60 years were included. Reviews, meta-analyses, case reports, retrospective, cross-sectional, and theoretical studies were excluded. Study screening and data extraction were conducted by two researchers independently. Random-effects meta-analysis was used to estimate pooled adjusted hazard ratios (HRs). Publication bias was evaluated via the symmetry of funnel plots and Egger tests. The Newcastle Ottawa Scale was used to assess the risk of bias. The quality of evidence of synthesis was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE). The primary outcome was any stroke, including non-fatal, fatal, ischemic and hemorrhagic sub-types. Seventeen studies of 57,761 patients in total were included in the meta-analysis. A positive association was found between depressive disorder or symptoms and stroke risk (HR: 1.39; 95% CI: 1.22-1.58; p < 0.001). Late-life depression or depressive symptoms are a significant risk factor for stroke in older people. Regular assessment and more effective management of associated comorbidities are recommended to reduce stroke risk.

Atrial fibrillation, transient ischaemic attack and stroke in older people. A themed collection in age and ageing journal

With an increase in the ageing population, there is a rise in the burden of cardiovascular disease. Age and Ageing have compiled collections of their key cardiovascular themed papers. The first Age and Ageing Cardiovascular Collection focussed on blood pressure, coronary heart disease and heart failure. In this second collection, publications since 2011 were selected with emphasis on atrial fibrillation, transient ischaemic attack (TIA) and stroke. The prevalence of TIA and stroke increases as people get older. In this commentary we summarise studies published in Age and Ageing that bring to the fore the need for a multidisciplinary, person-centred approach to care, conscientious identification of risk factors and their management and prevention strategies, which will inform policy ultimately reducing the burden of cost placed by stroke care on healthcare financing. Read the latest Cardiovascular Collection here.

Low-carbohydrate diet score and the risk of stroke in older people: Guangzhou Biobank Cohort Study and meta-analysis of cohort studies

ObjectivesTo our knowledge, evidence regarding the association of a low-carbohydrate diet (LCD) with the risk for stroke is limited. The aim of this study was to examine the association between an LCD and stroke in a population with relatively high-carbohydrate intake and risk for stroke and use a meta-analysis to update the evidence. MethodsThe study included 19 850 participants aged ≥50 y without stroke history at baseline in the Guangzhou Biobank Cohort Study. LCD score was calculated based on the percentage of energy from carbohydrate, protein, and fat (range 0–30 points), with a higher score indicating a lower intake of carbohydrate and a higher intake of fat and protein. ResultsDuring an average follow-up of 13.1 y, 1661 stroke events and deaths occurred, including 1255 ischemic strokes. The second, versus the lowest quartile of animal-based LCD scores, were associated with lower risks for all stoke and ischemic stroke (hazards ratio [HR], 0.87; 95% confidence interval [CI], 0.77–0.997, and HR, 0.83; 95% CI, 0.72–0.97). Non-significant associations of plant-based or total LCD scores with the risk for stoke were found. ConclusionsIn a population consuming high levels of carbohydrates and low levels of protein and fat, a moderate level of animal-based LCD, but not plant-based LCD, was associated with a lower risk for stroke.

Brain white matter hyperintensities-predicted age reflects neurovascular health in middle-to-old aged subjects.

age-related neurovascular structural and functional impairment is a major aetiology of dementia and stroke in older people. There is no single marker representative of neurovascular biological age yet. this study aims to develop and validate a white matter hyperintensities (WMH)-based model for characterising individuals' neurovascular biological age. in this prospective single-site study, the WMH-based age-prediction model was constructed based on WMH volumes of 491 healthy participants (21-89 years). In the training dataset, the constructed linear-regression model with log-transformed WMH volumes showed well-balanced complexity and accuracy (root mean squared error, RMSE = 10.20 and mean absolute error, MAE = 7.76 years). This model of neurovascular age estimation was then applied to a middle-to-old aged testing dataset (n = 726, 50-92 years) as the testing dataset for external validation. the established age estimator also had comparable generalizability with the testing dataset (RMSE = 7.76 and MAE = 6.38 years). In the testing dataset, the WMH-predicted age difference was negatively associated with visual executive function. Individuals with older predicted-age for their chronological age had greater cardiovascular burden and cardiovascular disease risks than individuals with normal or delayed predicted age. These associations were independent of chronological age. our model is easy to use in clinical practice that helps to evaluate WMH severity objective to chronological age. Current findings support our WMH-based age measurement to reflect neurovascular health and have potential diagnostic and prognostic value for clinical or research purposes in age-related neurovascular disorders.

Reperfusion therapy for acute ischemic stroke in older people: An observational real-life study.

While randomized clinical trials have shown the benefit of thrombolysis and endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS), we aimed to describe in a real-life study the differences between older (>80 years old) and younger patients treated for AIS. Thousand patients treated with thrombolysis and/or EVT were consecutively included in a prospective monocentric database (admitted from December 2015 to May 2019 in our comprehensive stroke center). Demographic data with detailed history, baseline physical examinations and treatments, laboratory and imaging data, prestroke functional status, and outcome 3 months after stroke were analyzed. Older patients (n=357) had more baseline comorbidities and lower levels of prestroke independence (modified Rankin scale ≤2; 67.2% vs. 96.1%) and more severe strokes (median National Institute of Health Stroke Score [NIHSS] 15 vs. 12; p < 0.001) than younger patients (n=643). There was no difference in the reperfusion treatments used or treatment timelines. In older patients, good functional status at 3months was less common (29.7% vs. 61.3%) and mortality was higher (37.1% vs. 11.4%) than in younger patients. Younger age was independently associated with better prognosis (odds ratio [OR] 0.37, 95% confidence interval [CI]: 0.20-0.67; p=0.001) and lower mortality (OR 4.38, 95% CI: 2.11-9.09; p < 0.001). Among older adults, features associated with good outcome at 3months were age (OR 0.89, 95% CI: 0.81-0.97; p=0.01), initial NIHSS (OR 0.89, 95% CI: 0.83-0.94; p < 0.0001), and absence of severe leukoaraiosis, anticoagulant treatment, and symptomatic intracerebral hemorrhage following reperfusion therapy (respectively, OR 0.42, 95% CI: 0.19-0.93; p=0.03; OR=0.07, 95% CI: 0.01-0.70; p=0.02; and OR=0.07, 95% CI: 0.01-0.61; p=0.02). Although reperfusion therapy was less successful in older patients, these patients may benefit from acute recanalization despite their age. With an increasing older adult population, high-quality prospective studies are still required to better predict functional outcome and clarify the criteria that would allow better selection of appropriate treatment.

Pharmacological management of stroke in older people

AbstractStroke is one of the most common causes of death and disability. It is more common in people aged 65 years or older. Most patients survive the stroke and live with their disabilities, impacting their quality of life and day‐to‐day function to varying degrees. Stroke sequelae can be associated with a broad range of physical, functional, cognitive, behavioural, emotional and socioeconomic consequences. Optimising the management of stroke and its complications, as well as strategies to prevent stroke recurrence, using both non‐pharmacological and pharmacological approaches, is crucial. This narrative review covers the pharmacological management of acute stroke, common post‐stroke complications and secondary prevention, with a focus on older people.

Current characteristics and early functional outcome of older stroke patients: a population-based study (Dijon Stroke Registry).

the ongoing growing and ageing population is associated with an increase in older patients suffering a stroke. We aimed to assess the current profile of these patients in a population-based setting. all patients with acute stroke were prospectively identified among residents of Dijon, France, between 2013 and 2017, using a population-based registry. Characteristics and early outcome of patients were compared according to age groups. 1,288 stroke cases were recorded (median age: 81.1years, interquartile range: 66.1-86.7, 54% women). Patients aged 75-85years and those >85years accounted for 27.6 and 33.9% of overall cases. Increasing age was associated with a greater prevalence of vascular risk factors, pre-existing cognitive impairment and handicap, higher initial severity, more frequent cardioembolic ischemic stroke, post-stroke pulmonary infection and delirium. Only 41% of patients aged 75-85years and 18% of those aged >85years had a good early recovery. Compared with patients aged <75years, patients aged 75-85years [adjusted odds ratio (OR) = 2.61; 95% confidence interval (CI): 1.74-3.93, P < 0.001] and those aged >85years (adjusted OR = 7.18; 95% CI: 4.58-11.3, P < 0.001) had an increased risk of poor post-stroke functional outcome. Among survivors, the proportion of patients discharged to home was 60% in age group <75years, compared with 49% in patients aged 75-85years and 29% in those aged >85years. Thirty per cent of patients >85years old required a long-term care institution. the increasing burden of stroke in older people has major implications for future treatment strategies and need for dedicated care facilities.

A clinical audit of oral anticoagulant therapy in aged care residents with atrial fibrillation.

Background Atrial fibrillation (AF) is a risk factor for stroke in older people. Oral anticoagulants can reduce stroke risk but they are commonly under prescribed in the elderly, often due to concerns regarding the risk of bleeding. Prescribing in aged care residents may also be further complicated by associated geriatric conditions such as dementia and risk of falls. Systematic assessment of stroke and bleed risk can help identify people with AF expected to benefit from anticoagulant therapy and optimise prescribing. Objective The aim of this study was to assess the prescribing of anticoagulants in elderly aged care residents in accordance with Australian guideline recommendations. Setting Nineteen aged care facilities across southeast Queensland. Method A clinical audit of anticoagulant therapy in aged care residents was conducted. Main outcome measure Information was collected from the records of residents with non-valvular AF to assess the risk of stroke and bleeding and compare this prescribing to current evidence-based guidelines for anticoagulation in AF. Results A total of 1754 residents were screened with 359 (20.4%) identified to have a diagnosis of non-valvular AF. There were 356 (99.2%) residents with non-valvular AF and a sufficiently high risk of stroke to warrant the use of an anticoagulant. Of these, 172 (48.3%) were prescribed an oral anticoagulant and 40 (11.2%) residents had a documented decision not to prescribe oral anticoagulants in their records. The majority of residents prescribed anticoagulation were receiving non-vitamin K antagonists (76.8%). The prescribed dose was consistent with recommendations for 44.8% of residents prescribed oral anticoagulant therapy. Conclusion Many residents with non-valvular AF and significant risk of stroke were not receiving oral anticoagulation despite a lack of documented reason for non-prescribing. Non-vitamin K antagonists were widely prescribed but dosing of these agents could still be improved. There remains a need to improve anticoagulant prescribing for aged care residents and optimise stroke prevention in this population.

Association between systolic blood pressure and first ischemic stroke in the Chinese older hypertensive population.

ObjectiveThis study aimed to evaluate the association between systolic blood pressure (SBP) and first ischemic stroke in older people with hypertension in the community.MethodsThis retrospective cohort study included 3315 residents who were hypertensive and older than 60 years in Guangdong, China.ResultsA total of 1475 men and 1840 women aged 71.41±7.20 years were included. All subjects had a median follow-up duration for 5.5 years and 206 subjects reached the endpoint. The prevalence of first ischemic stroke increased with a higher SBP. SBP expressed as a continuous variable (hazard ratio [HR], 1.01; 95% confidence interval [CI], 1.00–1.02) and categorical variable (HRs, 1.00, 1.06, 1.17, 1.39, and 1.60 for increasing blood pressure from < 120–≥150 mmHg), was significantly associated with a higher risk of first ischemic stroke. Moreover, a fully adjusted model indicated an obvious increased risk in the SBP ≥150 mmHg group (HR, 1.60; 95% CI, 1.15–2.71) and the SBP 140–149 mmHg group (HR, 1.39; 95% CI, 1.01–2.39).ConclusionsHigh SBP was independently associated with the risk of first ischemic stroke in hypertensive residents in the community aged older than 60 years. SBP ≥140 mmHg increases the risk of first ischemic stroke.

Determinants of anticoagulant therapy in atrial fibrillation at discharge from a geriatric ward: cross sectional study

Oral anticoagulants (OACs) are effective in preventing stroke in older people with atrial fibrillation (AF), but they are often underused in this particularly high-risk population. The aim of the study was to identify health and functional determinants of oral anticoagulant therapy (OA) in AF at discharge from a geriatric sub-acute ward. A cross-sectional study was conducted and patients who presented with atrial fibrillation were analyzed. They were interviewed, examined, assessed with comprehensive geriatric assessment protocol, and had their hospital records analyzed. Relative risks for OA were counted and multivariable logistic regression model was built. 95 patients took part in the study (22.8% of 416 consecutively admitted to the department, 31.9% men, 73.7% 80 + year-old). 25.8% of them were on antiplatelet drugs and 58.9% on OACs. The percentage on OACs increased significantly to 73.7% at discharge (p = 0.004), mainly due to the new OACs prescription (from 11.8 to 33.3%; p < 0.001). Severe frailty (7 point Clinical Frailty Scale ≥ 6) and anemia presence, but not the risk of bleeding according to the HAS-BLED score, significantly decreased the probability of OACs prescription at discharge. There was also a trend for an association of OACs prescription with the higher total score of CHA2DS2-VASc scale. We conclude that in the real-life population of patients with AF comprehensive geriatric assessment might allow to increase significantly the number of patients on OACs, but it is limited by patient’s frailty status and anemia diagnosis.

Appropriateness of oral anticoagulant therapy prescription and its associated factors in hospitalized older people with atrial fibrillation.

Although oral anticoagulants (OACs) are effective in preventing stroke in older people with atrial fibrillation (AF), they are often underused in this particularly high-risk population. The aim of the present study was to assess the appropriateness of OAC prescription and its associated factors in hospitalized patients aged 65years or older. Data were obtained from the retrospective phase of Simulation-based Technologies to Improve the Appropriate Use of Oral Anticoagulants in Hospitalized Elderly Patients With Atrial Fibrillation (SIM-AF) study, held in 32 Italian internal medicine and geriatric wards. The appropriateness of OAC prescription was assessed, grouping patients in those who were and were not prescribed OACs at hospital discharge. Multivariable logistic regression was used to establish factors independently associated with the appropriateness of OAC prescription. A total of 328 patients were included in the retrospective phase of the study. Of these, almost 44% (N = 143) were inappropriately prescribed OACs, being mainly underprescribed or prescribed an inappropriate antithrombotic drug (N = 88). Among the patients prescribed OACs (N=221), errors in the prescribed doses were the most frequent cause of inappropriate use (N=55). Factors associated with a higher degree of patient frailty were inversely associated with the appropriateness of OAC prescription. In hospitalized older patients with AF, there is still a high prevalence of inappropriate OAC prescribing. Characteristics usually related to frailty are associated with the inappropriate prescribing. These findings point to the need for targeted interventions designed for internists and geriatricians, aimed at improving the appropriate prescribing of OACs in this complex and high-risk population.

Relationship of Self-Rated Health to Stroke Incidence and Mortality in Older Individuals with and without a History of Stroke: A Longitudinal Study of the MRC Cognitive Function and Ageing (CFAS) Population.

IntroductionPoor self-rated health (SRH) has been associated with increased risk of death and poor health outcomes even after adjusting for confounders. However its’ relationship with disease-specific mortality and morbidity has been less studied. SRH may also be particularly predictive of health outcomes in those with pre-existing conditions. We studied whether SRH predicts new stroke in older people who have never had a stroke, or a recurrence in those with a prior history of stroke.MethodsMRC CFAS I is a multicentre cohort study of a population representative sample of people in their 65th year and older. A comprehensive interview at baseline included questions about presence of stroke, self-rated health and functional disability. Follow-up at 2 years included self-report of stroke and stroke death obtained from death certificates. Multiple logistical regression determined odds of stroke at 2 years adjusting for confounders including disability and health behaviours. Survival analysis was performed until June 2014 with follow-up for up to 13 years.Results11,957 participants were included, of whom 11,181 (93.8%) had no history of stroke and 776 (6.2%) one or more previous strokes. Fewer with no history of stroke reported poor SRH than those with stroke (5 versus 21%). In those with no history of stroke, poor self-rated health predicted stroke incidence (OR 1.5 (1.1–1.9)), but not stroke mortality (OR 1.2 (0.8–1.9)) at 2 years nor for up to 13 years (OR 1.2(0.9–1.7)). In those with a history of stroke, self-rated health did not predict stroke incidence (OR 0.9(0.6–1.4)), stroke mortality (OR 1.1(0.5–2.5)), or survival (OR 1.1(0.6–2.1)).ConclusionsPoor self-rated health predicts risk of stroke at 2 years but not stroke mortality among the older population without a previous history of stroke. SRH may be helpful in predicting who may be at risk of developing a stroke in the near future.

Research roundup: July 2015

In brief ▪Breastfeeding for at least 6 months may reduce the number of childhood leukaemias by almost a fifth ▪ Statins and fibrates may reduce the incidence of stroke in older people by about 30% ▪ Proton pump inhibitors may be associated with an increased risk of myocardial infarction and cardiovascular mortality ▪ Te ban on smoking in public places probably reduced hospitalizations for respiratory tract infections in children by about 11 000 a year ▪ A recently launched combination for type 2 diabetes reduces weight, HbA1c and risk of hypoglycaemia

Lipid-lowering drugs may be effective in the prevention of stroke in older people

Lipid-lowering drugs may be effective in the prevention of stroke in older people

Research into practice: management of atrial fibrillation in general practice.

Atrial fibrillation (AF) is the commonest cardiac arrhythmia, characterised by an irregularly irregular pulse, and an absence of P waves on electrocardiogram (ECG). It is a major independent risk factor for thromboembolic disease, particularly stroke with which it is associated with a fivefold increase in risk. Prevalence data for AF have been notoriously difficult to ascertain with estimates of 5–10% in the population aged ≥65 years. A review of four large community-based studies of AF suggested that the overall community prevalence in the US is 0.89%. Our primary care studies in the UK indicate that over 10% of people aged >75 years experience AF1 and 4% of people with AF are undiagnosed.2 Prevalence increases sharply with age: 2.3% of people aged ≥40 years; 5.9% of people aged ≥65 years, and 10% of those >80 years. The vast majority (84%) of people with AF are ≥65 years. AF is a particularly important risk factor for stroke in older people: while 15% of all strokes are associated with the arrhythmia, it is associated with 36% of strokes in people aged >80 years. The incidence of new cases of AF in people aged ≥65 years is of the order of 1% per annum. The risk of stroke can be reduced through the use of anticoagulant agents; for example, warfarin has been found to be consistently effective for the prevention of ischaemic stroke with a reduction in the incidence of all strokes of 68% (95% confidence interval = 50% to 79%), representing an absolute annual reduction of 3.1% ( P <0.001). Newer agents (dabigatran, rivaroxaban, and apixaban) have been found in large randomised controlled trials (RCTs) to be at least as effective and are now to be considered alongside warfarin when deciding on anticoagulation.3 Despite the robust evidence base for effective stroke …

Anticoagulation for Non‐Valvular Atrial Fibrillation in Older People

ABSTRACTAtrial fibrillation (AF) is a common arrhythmia that increases in prevalence with advancing age. Systemic thromboembolism, a complication of AF and ischaemic stroke, is the most frequent clinical manifestation. The risk of stroke is increased in the presence of factors such as advancing age, heart failure, hypertension, diabetes and history of stroke. Long‐term anticoagulation with warfarin has been the standard treatment for stroke prevention in patients with AF. In older people anticoagulation is associated with an increased risk of bleeding. Therefore, managing AF in older people can be a clinical challenge because not only are they at a high risk of thromboembolism but also of bleeding. Stroke risk stratification schemes have been developed to guide assessment of risks versus benefits. Other considerations in older people include monitoring anticoagulation, and assessing falls risk, compliance and the potential for drug interactions. A range of novel oral anticoagulants, such as direct thrombin inhibitors and factor Xa inhibitors, have been developed. These anticoagulants have demonstrated advantages in safety, efficacy and convenience of use in large randomised clinical trials. These novel anticoagulants could provide alternatives to warfarin for preventing stroke in older people with AF.

Stroke as a medical emergency in older people

SummaryIn the last 20 years a realization has developed that acute stroke is a condition that benefits from early intensive investigation and treatment. Older people are historically less likely to receive such active management through a combination of limited evidence due to their exclusion from clinical trials and a level of ‘therapeutic nihilism’ regarding older subjects with severe, acute illness.There is increasing evidence that many acute therapies, including thrombolysis, benefit older stroke patients. Older subjects may not achieve as good results as younger groups but differential benefits are often comparable when expected outcomes are considered. Risk of haemorrhagic complications with thrombolysis is not substantially increased and older subjects are now receiving this therapy despite a dearth of relevant trial data.Intensive physiological monitoring and stroke unit care has been found to be of benefit to patients of all ages. Surgical options for intracerebral haemorrhage are limited, but there is little difference in the management of intracranial haemorrhage in older people. There is unlikely to be a benefit to surgical hemicraniectomy for cerebral infarction in those &gt;60 years. In conclusion, active management for acute stroke in older people is frequently beneficial and age should not be a barrier to such care.

Adipocytokines and risk of stroke in older people: a nested case–control study

Inflammation may play an important role in atherothrombosis and in promoting cerebral damage after stroke. We hypothesized that plasma adipocytokine concentrations would be associated with risk of stroke in older people. Nested case-control study from the Prospective Study of Pravastatin in the Elderly (PROSPER). Subjects were aged 70-82 years and followed up for a mean of 3.2 years: 266 incident stroke cases (179 confirmed as ischaemic) were compared with 532 controls matched for age, gender and treatment allocation (pravastatin or placebo). Adipocytokines [adiponectin, interleukin- (IL-)18 and tumour necrosis factor (TNF)alpha] were measured on stored baseline plasma samples. Elevated plasma adiponectin was associated with lower risk of ischaemic stroke on univariate analysis: odds ratio (OR) 0.78 per 1 SD increase (95% CI 0.62-0.97). There were no associations of IL-18 or TNFalpha with risk for ischaemic or total strokes. In multivariate models the independent predictors of ischaemic stroke were prior cerebrovascular accident (OR 2.68, 95% CI 1.60-4.50), any alcohol use (1.98, 1.33-2.94), triglycerides (1.40, 1.11-1.77), Barthel score (0.75, 0.58-0.96) and known diabetes (1.72, 1.04-2.83); adiponectin, IL-18 and TNFalpha did not contribute. A similar pattern of risk was seen for total stroke. Reduced adiponectin may have a modest role in the aetiology of ischaemic stroke in older people, however IL-18 and TNFalpha are unlikely to play any important part. These adipocytokines do not have clinical predictive utility; history of prior cerebrovascular accident, known diabetes mellitus, prior disability and higher alcohol intake explain much of the stroke risk.

Anticoagulation to Prevent Strokes in Older People with Atrial Fibrillation: Assembling Individualized Risk and Benefit Information

Anticoagulation to Prevent Strokes in Older People with Atrial Fibrillation: Assembling Individualized Risk and Benefit Information