Primary stroke prevention worldwide: translating evidence into action

Stroke is the second leading cause of death and the third leading cause of disability worldwide and its burden is increasing rapidly in low-income and middle-income countries, many of which are unable to face the challenges it imposes. In this Health Policy paper on primary stroke prevention, we provide an overview of the current situation regarding primary prevention services, estimate the cost of stroke and stroke prevention, and identify deficiencies in existing guidelines and gaps in primary prevention. We also offer a set of pragmatic solutions for implementation of primary stroke prevention, with an emphasis on the role of governments and population-wide strategies, including task-shifting and sharing and health system re-engineering. Implementation of primary stroke prevention involves patients, health professionals, funders, policy makers, implementation partners, and the entire population along the life course.

Optimal measures for primary care physician encounters after stroke and association with survival: a data linkage study

BACKGROUND AND PURPOSE

Primary care physicians provide ongoing management after stroke. However, little is known about how best to measure physician encounters with reference to longer term outcomes. We aimed to compare methods for measuring regularity and continuity of primary care physician encounters, based on survival following stroke using linked healthcare data.

METHODS

Data from the Australian Stroke Clinical Registry (2010-2014) were linked with Australian Medicare claims from 2009 2016. Physician encounters were ascertained within 18 months of discharge for stroke. We calculated three separate measures of continuity of encounters (consistency of visits with primary physician) and three for regularity of encounters (distribution of service utilization over time). Indices were compared based on 1-year survival using multivariable Cox regression models. The best performing measures of regularity and continuity, based on model fit, were combined into a composite 'optimal care' variable.

RESULTS

Among 10,728 registrants (43% female, 69% aged ≥65 years), the median number of encounters was 17. The measures most associated with survival (hazard ratio [95% confidence interval], Akaike information criterion [AIC], Bayesian information criterion [BIC]) were the: Continuity of Care Index (COCI, as a measure of continuity; 0.88 [0.76 1.02], p=0.099, AIC=13746, BIC=13855) and our persistence measure of regularity (encounter at least every 6 months; 0.80 [0.67 0.95], p=0.011, AIC=13742, BIC=13852). Our composite measure, persistent plus COCI ≥80% (24% of registrants; 0.80 [0.68 0.94], p=0.008, AIC=13742, BIC=13851), performed marginally better than our persistence measure alone.

CONCLUSIONS

Our persistence measure of regularity or composite measure may be useful when measuring physician encounters following stroke.

Co-Designing a New Yoga-Based Mindfulness Intervention for Survivors of Stroke: A Formative Evaluation

Movement-based mindfulness interventions (MBI) are complex, multi-component interventions for which the design process is rarely reported. For people with stroke, emerging evidence suggests benefits, but mainstream programs are generally unsuitable. We aimed to describe the processes involved and to conduct a formative evaluation of the development of a novel yoga-based MBI designed for survivors of stroke. We used the Medical Research Council complex interventions framework and principles of co-design. We purposefully approached health professionals and consumers to establish an advisory committee for developing the intervention. Members collaborated and iteratively reviewed the design and content of the program, formatted into a training manual. Four external yoga teachers independently reviewed the program. Formative evaluation included review of multiple data sources and documentation (e.g., formal meeting minutes, focus group discussions, researcher observations). The data were synthesized using inductive thematic analysis. Three broad themes emerged: (a) MBI content and terminology; (b) manual design and readability; and (c) barriers and enablers to deliver the intervention. Various perspectives and feedback on essential components guided finalizing the program. The design phase of a novel yoga-based MBI was strengthened by interdisciplinary, consumer contributions and peer review. The 12-week intervention is ready for testing among survivors of stroke.

ASHA-Led Community-Based Groups to Support Control of Hypertension in Rural India Are Feasible and Potentially Scalable

Background: To improve the control of hypertension in low- and middle-income countries, we trialed a community-based group program co-designed with local policy makers to fit within the framework of India's health system. Trained accredited social health activists (ASHAs), delivered the program, in three economically and developmentally diverse settings in rural India. We evaluated the program's implementation and scalability. Methods: Our mixed methods process evaluation was guided by the United Kingdom Medical Research Council guidelines for complex interventions. Meeting attendance reports, as well as blood pressure and weight measures of attendees and adherence to meeting content and use of meeting tools were used to evaluate the implementation process. Thematic analysis of separate focus group discussions with participants and ASHAs as well as meeting reports and participant evaluation were used to investigate the mechanisms of impact. Results: Fifteen ASHAs led 32 community-based groups in three rural settings in the states of Kerala and Andhra Pradesh, Southern India. Overall, the fidelity of intervention delivery was high. Six meetings were delivered over a 3-month period to each of the intervention groups. The mean number of meetings attended by participants at each site varied significantly, with participants in Rishi Valley attending fewer meetings [mean (SD) = 2.83 (1.68)] than participants in West Godavari (Tukeys test, p = 0.009) and Trivandrum (Tukeys test, p < 0.001) and participants in West Godavari [mean (SD) = 3.48 (1.72)] attending significantly fewer meetings than participants in Trivandrum [mean (SD) = 4.29 (1.76), Tukeys test, p < 0.001]. Culturally appropriate intervention resources and the training of ASHAs, and supportive supervision of them during the program were critical enablers to program implementation. Although highly motivated during the implementation of the program ASHA reported historical issues with timely remuneration and lack of supportive supervision. Conclusions: Culturally appropriate community-based group programs run by trained and supported ASHAs are a successful and potentially scalable model for improving the control of hypertension in rural India. However, consideration of issues related to unreliable/insufficient remuneration for ASHAs, supportive supervision and their formal role in the wider health workforce in India will be important to address in future program scale up. Trial Registration: Clinical Trial Registry of India [CTRI/2016/02/006678, Registered prospectively].

Case-Fatality and Functional Outcome after Subarachnoid Hemorrhage (SAH) in INternational STRoke oUtComes sTudy (INSTRUCT)

BACKGROUND

There are few large population-based studies of outcomes after subarachnoid hemorrhage (SAH) than other stroke types.

METHODS

We pooled data from 13 population-based stroke incidence studies (10 studies from the INternational STRroke oUtComes sTudy (INSTRUCT) and 3 new studies; N=657). Primary outcomes were case-fatality and functional outcome (modified Rankin scale score 3-5 [poor] vs. 0-2 [good]). Harmonized patient-level factors included age, sex, health behaviours (e.g. current smoking at baseline), comorbidities (e.g.history of hypertension), baseline stroke severity (e.g. NIHSS >7) and year of stroke. We estimated predictors of case-fatality and functional outcome using Poisson regression and generalized estimating equations using log-binomial models respectively at multiple timepoints.

RESULTS

Case-fatality rate was 33% at 1 month, 43% at 1 year, and 47% at 5 years. Poor functional outcome was present in 27% of survivors at 1 month and 15% at 1 year. In multivariable analysis, predictors of death at 1-month were age (per decade increase MRR 1.14 [1.07-1.22]) and SAH severity (MRR 1.87 [1.50-2.33]); at 1 year were age (MRR 1.53 [1.34-1.56]), current smoking (MRR 1.82 [1.20-2.72]) and SAH severity (MRR 3.00 [2.06-4.33]) and; at 5 years were age (MRR 1.63 [1.45-1.84]), current smoking (MRR 2.29 [1.54-3.46]) and severity of SAH (MRR 2.10 [1.44-3.05]). Predictors of poor functional outcome at 1 month were age (per decade increase RR 1.32 [1.11-1.56]) and SAH severity (RR 1.85 [1.06-3.23]), and SAH severity (RR 7.09 [3.17-15.85]) at 1 year.

CONCLUSION

Although age is a non-modifiable risk factor for poor outcomes after SAH, however, severity of SAH and smoking are potential targets to improve the outcomes.

Treatment with Multiple Therapeutic Classes of Medication is Associated with Survival after Stroke

INTRODUCTION

Treatment with several therapeutic classes of medication is recommended for secondary prevention of stroke. We analysed the associations between the number of classes of prevention medications supplied within 90 days post-discharge for ischemic stroke (IS)/transient ischemic attack (TIA) and survival.

PATIENTS AND METHODS

Retrospective cohort study of adults with first-ever IS/TIA (2010-2014) from the Australian Stroke Clinical Registry individually linked with data from national pharmaceutical and Medicare claims. Exposure was the number of classes of recommended medications, i.e. blood pressure-lowering, antithrombotic or lipid-lowering agents, supplied to patients within 90 days post-discharge for IS/TIA. The longitudinal association between the number of classes of medications and survival was evaluated with Cox proportional hazards regression models using the landmark approach. A landmark date of 90 days post-hospital discharge was used to separate exposure and outcome periods and only patients who survived until this date were included.

RESULTS

Of 8,429 patients (43% female, median age 74 years, 80% IS), 607 (7%) died in the year following 90 days post-discharge. Overall, 56% of patients were supplied all three classes of medications, 28% two classes of medications, 11% one class of medications, and 5% no class of medications. Compared to patients supplied all three medication classes, adjusted hazard ratios for all-cause mortality ranged from 1.43 (95% confidence interval [CI]: 1.18-1.72) in those supplied two medication classes to 2.04 (CI: 1.44-2.88) in those supplied with no medication class.

CONCLUSION

Treatment with all three classes of guideline-recommended medications within 90 days post-discharge was associated with better survival. Ongoing efforts are required to ensure optimal pharmacological intervention for secondary prevention of stroke.

Intra-operative and early post-operative prediction of cardiac surgery-associated acute kidney injury: Urinary oxygen tension compared with plasma and urinary biomarkers

Acute kidney injury (AKI) is a common and serious post-operative complication of cardiac surgery. The value of a predictive biomarker is determined not only by its predictive efficacy, but also by how early this prediction can be made. For a biomarker of cardiac surgery-associated AKI, this is ideally during the intra-operative period. Therefore, in 82 adult patients undergoing cardiac surgery requiring cardiopulmonary bypass (CPB), we prospectively compared the predictive efficacy of various blood and urinary biomarkers with that of continuous measurement of urinary oxygen tension (UPO₂ ) at pre-determined intra- and post-operative time-points. None of the blood or urine biomarkers we studied showed predictive efficacy for post-operative AKI when measured intra-operatively. When treated as a binary variable (≤ or > median for the whole cohort), the earliest excess risk of AKI was predicted by an increase in urinary neutrophil gelatinase-associated lipocalin (NGAL) at 3 h after entry into the intensive care unit (odds ratio [95% confidence limits], 2.86 [1.14-7.21], p = 0.03). Corresponding time-points were 6 h for serum creatinine (3.59 [1.40-9.20], p = 0.008), and 24 h for plasma NGAL (4.54 [1.73-11.90], p = 0.002) and serum cystatin C (6.38 [2.35-17.27], p = 0.001). In contrast, indices of intra-operative urinary hypoxia predicted AKI after weaning from CPB, and in the case of a fall in UPO₂ to ≤10 mmHg, during the rewarming phase of CPB (3.00 [1.19-7.56], p = 0.02). We conclude that continuous measurement of UPO₂ predicts AKI earlier than plasma or urinary NGAL, serum cystatin C, or early post-operative changes in serum creatinine.

Qualitative study of Stroke Survivors' Perceptions of Secondary Prevention

AIMS

To understand how survivors of stroke perceive secondary prevention and explore their perceived barriers and facilitators using the Theoretical Domains Framework.

DESIGN

A qualitative descriptive study.

METHODS

Nineteen survivors of stroke from three hospitals were recruited and interviewed from April 2019 to April 2020. The data were analysed deductively and inductively by content analysis strategies.

RESULTS

Three main themes of perception of secondary prevention were identified, these being active treatment-seeking, attention to taking medications and negative attitude towards lifestyle changes. Using deductive analysis, eight domains of the Theoretical Domains Framework were reported to be relevant in the secondary prevention behaviour of survivors of stroke that mapped to five 'barrier' domains (i.e. knowledge, physical skills, beliefs about capability, beliefs about consequences and optimism) as well as six 'facilitator' domains (i.e. knowledge, interpersonal skills, beliefs about capability, intention, emotion and social influences). Using inductive analysis we identified two additional important factors not falling in the domains of the Theoretical Domains Framework. These comprised female spouses' support and patients' economic autonomy, both of which could be classified as a facilitator or barrier.

CONCLUSION

Survivors of stroke perceive seeking treatment and using preventive medication as more important than modifying lifestyle behaviours. Knowledge and insight into the barriers and facilitators of secondary prevention in this specific context provides a theoretical and practical basis for the design of future secondary prevention interventions.

IMPACT

Stroke survivors' perceptions of secondary prevention, barriers and facilitators were explored in the context of a developing country. These findings highlight the need to better communicate the importance of improving lifestyle modification and medication adherence, and provide evidence for designing relevant interventions for stroke management in the community.

Global, regional, and national burden of stroke and its risk factors, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Regularly updated data on stroke and its pathological types, including data on their incidence, prevalence, mortality, disability, risk factors, and epidemiological trends, are important for evidence-based stroke care planning and resource allocation. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) aims to provide a standardised and comprehensive measurement of these metrics at global, regional, and national levels.

METHODS

We applied GBD 2019 analytical tools to calculate stroke incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and the population attributable fraction (PAF) of DALYs (with corresponding 95% uncertainty intervals [UIs]) associated with 19 risk factors, for 204 countries and territories from 1990 to 2019. These estimates were provided for ischaemic stroke, intracerebral haemorrhage, subarachnoid haemorrhage, and all strokes combined, and stratified by sex, age group, and World Bank country income level.

FINDINGS

In 2019, there were 12·2 million (95% UI 11·0-13·6) incident cases of stroke, 101 million (93·2-111) prevalent cases of stroke, 143 million (133-153) DALYs due to stroke, and 6·55 million (6·00-7·02) deaths from stroke. Globally, stroke remained the second-leading cause of death (11·6% [10·8-12·2] of total deaths) and the third-leading cause of death and disability combined (5·7% [5·1-6·2] of total DALYs) in 2019. From 1990 to 2019, the absolute number of incident strokes increased by 70·0% (67·0-73·0), prevalent strokes increased by 85·0% (83·0-88·0), deaths from stroke increased by 43·0% (31·0-55·0), and DALYs due to stroke increased by 32·0% (22·0-42·0). During the same period, age-standardised rates of stroke incidence decreased by 17·0% (15·0-18·0), mortality decreased by 36·0% (31·0-42·0), prevalence decreased by 6·0% (5·0-7·0), and DALYs decreased by 36·0% (31·0-42·0). However, among people younger than 70 years, prevalence rates increased by 22·0% (21·0-24·0) and incidence rates increased by 15·0% (12·0-18·0). In 2019, the age-standardised stroke-related mortality rate was 3·6 (3·5-3·8) times higher in the World Bank low-income group than in the World Bank high-income group, and the age-standardised stroke-related DALY rate was 3·7 (3·5-3·9) times higher in the low-income group than the high-income group. Ischaemic stroke constituted 62·4% of all incident strokes in 2019 (7·63 million [6·57-8·96]), while intracerebral haemorrhage constituted 27·9% (3·41 million [2·97-3·91]) and subarachnoid haemorrhage constituted 9·7% (1·18 million [1·01-1·39]). In 2019, the five leading risk factors for stroke were high systolic blood pressure (contributing to 79·6 million [67·7-90·8] DALYs or 55·5% [48·2-62·0] of total stroke DALYs), high body-mass index (34·9 million [22·3-48·6] DALYs or 24·3% [15·7-33·2]), high fasting plasma glucose (28·9 million [19·8-41·5] DALYs or 20·2% [13·8-29·1]), ambient particulate matter pollution (28·7 million [23·4-33·4] DALYs or 20·1% [16·6-23·0]), and smoking (25·3 million [22·6-28·2] DALYs or 17·6% [16·4-19·0]).

INTERPRETATION

The annual number of strokes and deaths due to stroke increased substantially from 1990 to 2019, despite substantial reductions in age-standardised rates, particularly among people older than 70 years. The highest age-standardised stroke-related mortality and DALY rates were in the World Bank low-income group. The fastest-growing risk factor for stroke between 1990 and 2019 was high body-mass index. Without urgent implementation of effective primary prevention strategies, the stroke burden will probably continue to grow across the world, particularly in low-income countries.

FUNDING

Bill & Melinda Gates Foundation.

The state of stroke services across the globe: Report of World Stroke Organization-World Health Organization surveys

BACKGROUND

Improving stroke services is critical for reducing the global stroke burden. The World Stroke Organization-World Health Organization-Lancet Neurology Commission on Stroke conducted a survey of the status of stroke services in low and middle-income countries (LMICs) compared to high-income countries.

METHODS

Using a validated World Stroke Organization comprehensive questionnaire, we collected and compared data on stroke services along four pillars of the stroke quadrangle (surveillance, prevention, acute stroke, and rehabilitation) in 84 countries across World Health Organization regions and economic strata. The World Health Organization also conducted a survey of non-communicable diseases in 194 countries in 2019.

RESULTS

Fewer surveillance activities (including presence of registries, presence of recent risk factors surveys, and participation in research) were reported in low-income countries than high-income countries. The overall global score for prevention was 40.2%. Stroke units were present in 91% of high-income countries in contrast to 18% of low-income countries (p < 0.001). Acute stroke treatments were offered in ∼ 60% of high-income countries compared to 26% of low-income countries (p = 0.009). Compared to high-income countries, LMICs provided less rehabilitation services including in-patient rehabilitation, home assessment, community rehabilitation, education, early hospital discharge program, and presence of rehabilitation protocol.

CONCLUSIONS

There is an urgent need to improve access to stroke units and services globally especially in LMICs. Countries with less stroke services can adapt strategies from those with better services. This could include establishment of a framework for regular monitoring of stroke burden and services, implementation of integrated prevention activities and essential acute stroke care services, and provision of interdisciplinary care for stroke rehabilitation.

Self-perceived acute psychological stress and risk of mortality, recurrence and disability after stroke: Mashhad Stroke Incidence Study

This longitudinal study was designed to evaluate the association between acute pre-stroke stress and the severity stroke and its outcomes including mortality, recurrence, disability and functional dependency. Patients with first-ever stroke (FES) were recruited from the Mashhad Stroke Incidence Study. Patients were asked about any acute severe pre-stroke stress in the 2 weeks prior to index stroke. Disability and functional disability were defined using modified the Rankin Scale and Barthel Index, respectively. We used logistic and ordinal regression tests to assess the association between acute pre-stroke stress and study outcomes. Among 624 patients with FES, 169 reported acute pre-stroke stress. Patients with acute pre-stroke stress were younger than those without stress (60.7 ± 14.4 vs. 66.2 ± 14.7; p < 0.001). The frequency of traditional vascular risk factors was not different in patients with and without acute pre-stroke stress. We did not find any association between acute pre-stroke stress and stroke outcomes. Although acute stress was common in our cohort, our results did not support an association between acute pre-stroke stress and the severity of stroke at admission and long-term stroke outcomes.

Adherence to evidence-based processes of care reduces one-year mortality after aneurysmal subarachnoid hemorrhage (aSAH)

BACKGROUND

There is limited research on the provision of evidence-based care and its association with outcomes after aneurysmal subarachnoid hemorrhage (aSAH).

AIMS

We examined adherence to evidence-based care after aSAH and associations with survival and discharge destination. Also, factors associated with evidence-based care including age, sex, Charlson comorbidity index, severity scores, and delayed cerebral ischemia and infarction were examined for association with survival and discharge destination.

METHODS

In a retrospective cohort (2010-2016) of all aSAH cases across two comprehensive cerebrovascular centres, we extracted 3 indicators of evidence-based aSAH care from medical records: (1) antihypertensives prior to aneurysm treatment, (2) nimodipine, and (3) aneurysm treatment (coiling/clipping). We defined 'optimal care' as receiving all eligible processes of care. Survival at 1 year was obtained by data linkage. We estimated (1) proportion of patients and characteristics associated with receiving processes of care, (2) associations between processes of care with 1-year mortality using cox-proportional hazard model and discharge destination with log binomial regression adjusting for age, sex, severity of aSAH, delayed cerebral ischemia and/or cerebral infarction and comorbidities. Sensitivity analyses explored effect modification of the association between processes of care and outcome by management type (active versus comfort measures).

RESULTS

Among 549 patients (69% women), 59% were managed according to the guidelines. Individual indicators were associated with lower 1-year mortality but not discharge destination. Optimal care reduced mortality at 1 year in univariable (HR 0.24 95% CI 0.17-0.35) and multivariable analyses (HR 0.51 95% CI 0.34-0.77) independent of age, sex, severity, comorbidities, and hospital network.

CONCLUSION

Adherence to processes of care reduced 1-year mortality after aSAH. Many patients with aSAH do not receive evidence-based care and this must be addressed to improve outcomes.

970Comparison of lab-and non-lab based absolute cardiovascular disease risk scores in rural India

Background

Over 75% of global cardiovascular (CVD) deaths occur in low-to-middle-income countries (LMICs).

In limited resource settings non-lab-based CVD risk algorithms could be as effective as lab-based algorithms in identifying high-risk groups. We aimed to compare the concordance between lab-and non-lab-based absolute CVD risk algorithms in a LMIC setting.

Methods

The study was conducted in the Rishi Valley, Andhra Pradesh, India. Over 8,000 participants were surveyed between 2012-2015. The 10-year absolute CVD risk score was computed and compared using lab-and-non-lab based Framingham and WHO algorithms.

Results

In participants aged 35-74 years, absolute CVD risk score increased with age, and was greater in men than women, for all risk assessment tools. Using the Framingham lab-based algorithm, 15.6% were categorized as high-risk while 14.5% were at high-risk using the non-lab-based algorithm. The non-lab-based Framingham risk score had close agreement and strong correlation with the lab-based Framingham risk score in women (90%, Spearman’s rho (rs)=0.81) and men (83%, rs=0.89). Similarly, the non-lab-based WHO risk score had close agreement and strong correlation with the lab-based WHO risk score in women (95%, rs=0.83) and men (92% rs=0.84). In both cases, agreement was better in women than men (P &lt; 0.05 for a two-sample test of proportions).

Conclusions

The effectiveness of non-lab-based Framingham and WHO algorithms are comparable to that of lab-based algorithms in discriminating high-and low-risk groups. However, the performance of non-lab-based risk score is better among women than men.

Key messages

Non-lab-based CVD risk algorithms could be effective and resource-efficient in LMIC settings, particularly among women.

961Absolute cardiovascular disease risk scores and medication use in rural India

Background

Low-to-middle-income countries (LMICs) have limited resources to tackle the burden of cardiovascular disease (CVD). Most screening guidelines recommend the use of absolute risk scoring to determine treatment, but there is uncertainty among policy makers and clinicians about which risk algorithm to choose. We aimed to compare laboratory-based absolute CVD risk algorithms in a LMIC setting.

Methods

The study was conducted in the Rishi Valley, Andhra Pradesh, India. Over 8,000 participants were surveyed between 2012-2015. The 10-year absolute risk was computed and compared using the Framingham, WHO, and Australian absolute risk CVD algorithms.

Results

In participants aged 35-74 years, 151 (3%) had prior CVD. In all algorithms, absolute CVD risk increased with age and was greater in men than women. Using the WHO algorithm 4% were characterized as high-risk while &gt;29% were at high-risk using the Australian risk tool. Agreement of risk classification among men ranged from a high of 84% (Spearman’s rho (rs) =0.92) between Australian and Framingham algorithms to 43% (rs=0.6) between the Australian and WHO risk scores. Among the high-risk population, only 15% were on lipid-lowering or antihypertensive therapy.

Conclusions

The Framingham and Australian risk scores enable some discrimination between high- and low-risk groups. However, the WHO algorithm underestimates these high-risk groups. Even though one third of the participants were at high-risk, most of them were not receiving recommended treatment.

Key messages

Lab-based CVD risk assessment tools have the potential in identifying high-risk populations in LMICs but the WHO risk scoring tool should be used with caution.

Quality of stroke guidelines in low- and middle-income countries: a systematic review

OBJECTIVE

To identify gaps in national stroke guidelines that could be bridged to enhance the quality of stroke care services in low- and middle-income countries.

METHODS

We systematically searched medical databases and websites of medical societies and contacted international organizations. Country-specific guidelines on care and control of stroke in any language published from 2010 to 2020 were eligible for inclusion. We reviewed each included guideline for coverage of four key components of stroke services (surveillance, prevention, acute care and rehabilitation). We also assessed compliance with the eight Institute of Medicine standards for clinical practice guidelines, the ease of implementation of guidelines and plans for dissemination to target audiences.

FINDINGS

We reviewed 108 eligible guidelines from 47 countries, including four low-income, 24 middle-income and 19 high-income countries. Globally, fewer of the guidelines covered primary stroke prevention compared with other components of care, with none recommending surveillance. Guidelines on stroke in low- and middle-income countries fell short of the required standards for guideline development; breadth of target audience; coverage of the four components of stroke services; and adaptation to socioeconomic context. Fewer low- and middle-income country guidelines demonstrated transparency than those from high-income countries. Less than a quarter of guidelines encompassed detailed implementation plans and socioeconomic considerations.

CONCLUSION

Guidelines on stroke in low- and middle-income countries need to be developed in conjunction with a wider category of health-care providers and stakeholders, with a full spectrum of translatable, context-appropriate interventions.

Intraoperative renal hypoxia and risk of cardiac surgery-associated acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is common after cardiac surgery requiring cardiopulmonary bypass. Renal hypoxia may precede clinically detectable AKI. We compared the efficacy of two indices of renal hypoxia, (i) intraoperative urinary oxygen tension (UPO₂ ) and (ii) the change in plasma erythropoietin (pEPO) during surgery, in predicting AKI. We also investigated whether the performance of these prognostic markers varies with preoperative patient characteristics.

METHODS

In 82 patients undergoing on-pump cardiac surgery, blood samples were taken upon induction of anesthesia and upon entry into the intensive care unit. UPO₂ was continuously measured throughout surgery.

RESULTS

Thirty-two (39%) patients developed postoperative AKI. pEPO increased during surgery, but this increase did not predict AKI, regardless of risk of postoperative mortality assessed by EuroSCORE-II. For patients categorized at higher risk by EuroSCORE-II >1.98 (median score for the cohort), UPO₂  ≤10 mmHg at any time during surgery predicted a 4.04-fold excess risk of AKI (p = .04). However, UPO₂ did not significantly predict AKI in lower-risk patients. UPO₂ significantly predicted AKI in patients who were older, had previous myocardial infarction, diabetes, lower preoperative serum creatinine, or shorter bypass times. pEPO and UPO₂ were only weakly correlated.

CONCLUSIONS

Intraoperative change in pEPO does not predict AKI. However, UPO₂ shows promise, particularly in patients with higher risk of operative mortality. The disparity between these two markers of renal hypoxia may indicate that UPO₂ reflects medullary oxygenation whereas pEPO reflects cortical oxygenation.

Greater Adherence to Secondary Prevention Medications Improves Survival After Stroke or Transient Ischemic Attack: A Linked Registry Study

BACKGROUND AND PURPOSE

Although a target of 80% medication adherence is commonly cited, it is unclear whether greater adherence improves survival after stroke or transient ischemic attack (TIA). We investigated associations between medication adherence during the first year postdischarge, and mortality up to 3 years, to provide evidence-based targets for medication adherence.

METHODS

Retrospective cohort study of 1-year survivors of first-ever stroke or TIA, aged ≥18 years, from the Australian Stroke Clinical Registry (July 2010-June 2014) linked with nationwide prescription refill and mortality data (until August 2017). Adherence to antihypertensive agents, statins, and nonaspirin antithrombotic medications was based on the proportion of days covered from discharge until 1 year. Cox regression with restricted cubic splines was used to investigate nonlinear relationships between medication adherence and all-cause mortality (to 3 years postdischarge). Models were adjusted for age, sex, socioeconomic position, stroke factors, primary care factors, and concomitant medication use.

RESULTS

Among 8363 one-year survivors of first-ever stroke or TIA (44% aged ≥75 years, 44% female, 18% TIA), 75% were supplied antihypertensive agents. In patients without intracerebral hemorrhage (N=7446), 84% were supplied statins, and 65% were supplied nonaspirin antithrombotic medications. Median adherence was ≈90% for each medication group. Between 1% and 100% adherence, greater adherence to statins or antihypertensive agents, but not nonaspirin antithrombotic agents, was associated with improved survival. When restricted to linear regions above 60% adherence, each 10% increase in adherence was associated with a reduction in all-cause mortality of 13% for antihypertensive agents (hazard ratio, 0.87 [95% CI, 0.81-0.95]), 13% for statins (hazard ratio, 0.87 [95% CI, 0.80-0.95]), and 15% for nonaspirin antithrombotic agents (hazard ratio, 0.85 [95% CI, 0.79-0.93]).

CONCLUSIONS

Greater levels of medication adherence after stroke or TIA are associated with improved survival, even among patients with near-perfect adherence. Interventions to improve medication adherence are needed to maximize survival poststroke.

Perspectives on rehabilitation for Aboriginal people with stroke: a qualitative study

BACKGROUND

Aboriginal and Torres Strait Islander (hereinafter respectfully termed Aboriginal) people have a greater incidence of stroke at a younger age than non-Indigenous people in Australia. The needs and preferences of Aboriginal people for rehabilitation and longer-term support remain largely unknown.

OBJECTIVES

To identify the long-term rehabilitation needs of Aboriginal people who have a stroke, from the perspectives of Aboriginal persons with stroke and health care providers.

METHODS

Aboriginal people who had experienced stroke in the previous three years were interviewed to obtain their experiences of rehabilitation care. Health professionals who provided care in each of six designated hospitals and nearby community health sites were involved in focus groups and individual interviews. Information obtained was thematically analyzed separately for Aboriginal people with stroke and health professionals, and compared using Nvivo.

RESULTS

Among six Aboriginal people with stroke and 78 healthcare providers, four main themes emerged: the importance of family; variable access to services; the impact of stroke on Aboriginal peoples' lives; and making positive choices. Communication and involvement of family was highlighted as essential for a shared understanding, particularly when making decisions about participating in short and long-term rehabilitation. Co-morbidities, conflicting priorities, and inadequate or inflexible services and transport compounded issues with changing life roles. Stories of resilience were also shared.

CONCLUSIONS

Aboriginal people report making positive lifestyle changes, but experience significant unmet rehabilitation needs. Addressing issues of communication, advocacy and flexible delivery should improve some of the shortfalls in service provision, particularly in regional and remote areas.

Utility of the Hospital Frailty Risk Score Derived From Administrative Data and the Association With Stroke Outcomes

[Figure: see text].

Protocol of a randomized controlled trial investigating the effectiveness of Recovery-focused Community support to Avoid readmissions and improve Participation after Stroke (ReCAPS)

RATIONALE

To address unmet needs, electronic messages to support person-centered goal attainment and secondary prevention may avoid hospital presentations/readmissions after stroke, but evidence is limited.

HYPOTHESIS

Compared to control participants, there will be a 10% lower proportion of intervention participants who represent to hospital (emergency/admission) within 90 days of randomization.

METHODS AND DESIGN

Multicenter, double-blind, randomized controlled trial with intention-to-treat analysis. The intervention group receives 12 weeks of personalized, goal-centered, and administrative electronic messages, while the control group only receive administrative messages. The trial includes a process evaluation, assessment of treatment fidelity, and an economic evaluation. Participants: Confirmed stroke (modified Rankin Score: 0-4), aged ≥18 years with internet/mobile phone access, discharged directly home from hospital. Randomization: 1:1 computer-generated, stratified by age and baseline disability. Outcomes assessments: Collected at 90 days and 12 months following randomization.

OUTCOMES

Primary outcomes include hospital emergency presentations/admissions within 90 days of randomization. Secondary outcomes include goal attainment, self-efficacy, mood, unmet needs, disability, quality-of-life, recurrent stroke/cardiovascular events/deaths at 90 days and 12 months, and death and cost-effectiveness at 12 months. Sample size: To test our primary hypothesis, we estimated a sample size of 890 participants (445 per group) with 80% power and two-tailed significance threshold of α = 0.05. Given uncertainty for the effect size of this novel intervention, the sample size will be adaptively re-estimated when outcomes for n = 668 are obtained, with maximum sample capped at 1100.

DISCUSSION

We will provide new evidence on the potential effectiveness, implementation, and cost-effectiveness of a tailored eHealth intervention for survivors of stroke.

Sex Disparities in Enrollment in Recent Randomized Clinical Trials of Acute Stroke: A Meta-analysis

Importance

The underenrollment of women in randomized clinical trials represents a threat to the validity of the evidence supporting clinical guidelines and potential disparities in access to novel treatments.

Objective

To determine whether women were underenrolled in contemporary randomized clinical trials of acute stroke therapies published in 9 major journals after accounting for their representation in underlying stroke populations.

Data Sources

MEDLINE was searched for acute stroke therapeutic trials published between January 1, 2010, and June 11, 2020.

Study Selection

Eligible articles reported the results of a phase 2 or 3 randomized clinical trial that enrolled patients with stroke and/or transient ischemic attack and examined a therapeutic intervention initiated within 1 month of onset.

Data Extraction

Data extraction was performed by 2 independent authors in duplicate. Individual trials were matched to estimates of the proportion of women in underlying stroke populations using the Global Burden of Disease database.

Main Outcomes and Measures

The primary outcome was the enrollment disparity difference (EDD), the absolute difference between the proportion of trial participants who were women and the proportion of strokes in the underlying disease populations that occurred in women. Random-effects meta-analyses of the EDD were performed, and multivariable metaregression was used to explore the associations of trial eligibility criteria with disparity estimates.

Results

The search returned 1529 results, and 115 trials (7.5%) met inclusion criteria. Of 121 105 randomized patients for whom sex was reported, 52 522 (43.4%) were women. The random-effects summary EDD was -0.053 (95% CI, -0.065 to -0.040), indicating that women were underenrolled by 5.3 percentage points. This disparity persisted across virtually all geographic regions, intervention types, and stroke types, apart from subarachnoid hemorrhage (0.117 [95% CI, 0.084 to 0.150]). When subarachnoid hemorrhage trials were excluded, the summary EDD was -0.067 (95% CI, -0.078 to -0.057). In the multivariable metaregression analysis, an upper age limit of 80 years as an eligibility criterion was associated with a 6-percentage point decrease in the enrollment of women.

Conclusions and Relevance

Further research is needed to understand the causes of the underenrollment of women in acute stroke trials. However, to maximize representation, investigators should avoid imposing age limits on enrollment.

Dynamic responses of renal oxygenation at the onset of cardiopulmonary bypass in sheep and man

INTRODUCTION

The renal medulla is susceptible to hypoxia during cardiopulmonary bypass (CPB), which may contribute to the development of acute kidney injury. But the speed of onset of renal medullary hypoxia remains unknown.

METHODS

We continuously measured renal medullary oxygen tension (MPO₂) in 24 sheep, and urinary PO₂ (UPO₂) as an index of MPO₂ in 92 patients, before and after induction of CPB.

RESULTS

In laterally recumbent sheep with a right thoracotomy (n = 20), even before CPB commenced MPO₂ fell from (mean ± SEM) 52 ± 4 to 41 ±5 mmHg simultaneously with reduced arterial pressure (from 108 ± 5 to 88 ± 5 mmHg). In dorsally recumbent sheep with a medial sternotomy (n = 4), MPO₂ was even more severely reduced (to 12 ± 12 mmHg) before CPB. In laterally recumbent sheep in which a crystalloid prime was used (n = 7), after commencing CPB, MPO₂ fell abruptly to 24 ±6 mmHg within 20-30 minutes. MPO₂ during CPB was not improved by adding donor blood to the prime (n = 13). In patients undergoing cardiac surgery, UPO₂ fell by 4 ± 1 mmHg and mean arterial pressure fell by 7 ± 1 mmHg during the 30 minutes before CPB. UPO₂ then fell by a further 12 ± 2 mmHg during the first 30 minutes of CPB but remained relatively stable for the remaining 24 minutes of observation.

CONCLUSIONS

Renal medullary hypoxia is an early event during CPB. It starts to develop even before CPB, presumably due to a pressure-dependent decrease in renal blood flow. Medullary hypoxia during CPB appears to be promoted by hypotension and is not ameliorated by increasing blood hemoglobin concentration.

The Incidence of Stroke in Indigenous Populations of Countries With a Very High Human Development Index: A Systematic Review Protocol

Background and Aims: Despite known Indigenous health and socioeconomic disadvantage in countries with a Very High Human Development Index, data on the incidence of stroke in these populations are sparse. With oversight from an Indigenous Advisory Board, we will undertake a systematic review of the incidence of stroke in Indigenous populations of developed countries or regions, with comparisons between Indigenous and non-Indigenous populations of the same region, though not between different Indigenous populations. Methods: Using PubMed, OVID-EMBASE, and Global Health databases, we will examine population-based incidence studies of stroke in Indigenous adult populations of developed countries published 1990-current, without language restriction. Non-peer-reviewed sources, studies including <10 Indigenous People, or with insufficient data to determine incidence, will be excluded. Two reviewers will independently validate the search strategies, screen titles and abstracts, and record reasons for rejection. Relevant articles will undergo full-text screening, with standard data extracted for all studies included. Quality assessment will include Sudlow and Warlow's criteria for population-based stroke incidence studies, the Newcastle-Ottawa Scale for risk of bias, and the CONSIDER checklist for Indigenous research. Results: Primary outcomes include crude, age-specific and/or age-standardized incidence of stroke. Secondary outcomes include overall stroke rates, incidence rate ratio and case-fatality. Results will be synthesized in figures and tables, describing data sources, populations, methodology, and findings. Within-population meta-analysis will be performed if, and where, methodologically sound and comparable studies allow this. Conclusion: We will undertake the first systematic review assessing disparities in stroke incidence in Indigenous populations of developed countries. Data outputs will be disseminated to relevant Indigenous stakeholders to inform public health and policy research.

Linking Australian Stroke Clinical Registry data with Australian government Medicare and medication dispensing claims data and the potential for bias

OBJECTIVE

We aim to report the accuracy of linking data from a non-government-held clinical quality registry to national claims data and identify associated sources of systematic bias.

METHODS

Patients with stroke or transient ischaemic attack admitted to hospitals participating in the Australian Stroke Clinical Registry (AuSCR) were linked with Medicare and medication dispensings through the Australian Medicare enrolment file (MEF). The proportion of registrants in the datasets was calculated and factors associated with a non-merge assessed using multivariable analyses.

RESULTS

A total of 17,980 AuSCR registrants (January 2010 - July 2014) were submitted for linkage (median age 76 years; 46% female; 67% ischaemic stroke); the proportion merged was 97% MEF, 93% Medicare and 95% medication dispensings. Data from registrants born in Asia were less likely to link with the MEF (adjusted Odds Ratio [aOR]: 0.20; 95%Confidence Interval [CI]: 0.15, 0.27). Data for those aged 85-plus compared to those under 65 years were less likely to merge with Medicare (aOR 0.25; 95%CI:0.21, 0.30) but more likely to merge with dispensing claims data (aOR: 2.15 (95%CI:1.71, 2.69). Implications for public health: Linkage between the AuSCR, a national clinical quality registry and Commonwealth datasets was achieved and potential sources of bias were identified.

Abstract P38: Pooled Analysis of Long and Short Term Outcomes After Subarachnoid Hemorrhage - International Stroke Outcomes Study (INSTRUCT)

Background: Outcomes after subarachnoid hemorrhage (SAH) have been rarely examined in large cohorts.

Methods: This is an extension of the International Stroke Outcomes Study (INSTRUCT) pooling 13 ‘ideal’ stroke incidence studies (n=657 with SAH from 1993-2017, median age 56 years; 46% men). The primary outcomes were mortality and functional outcome (mRS score 3-5). Harmonized study factors included age, sex, behaviors (current smoking, alcohol intake), comorbidities (history of hypertension, ischemic heart disease, atrial fibrillation), stroke severity (e.g. NIHSS score) and year of stroke. In the pooled dataset, we estimated predictors of mortality using Poisson regression, to estimate incidence rate ratio (IRR) at 1 month (11 studies), 1 year (12 studies) and 5 years (7 studies). Generalized equation estimates in the log-binomial family were used to calculate risk ratios (RRs) for predictors of poor functional outcome at 1 month (5 studies) and 1 year (8 studies).

Results: Mortality was 33% at 1 month, 43% at 1 year, and 47% at 5 years (Fig 1). Poor functional outcome was 25% at 1 month and 15% at 1 year (Fig 1). In multivariable analysis, age and stroke severity were associated with mortality at all time points, together with current smoking at 1 and 5 years, and history of hypertension at 5 years (Fig 2). Poor functional outcome was predicted by age (RR 1.03; 95% CI 1.01-1.04) at 1 month and by age (RR 1.04; 95% CI 1.00-1.08) and stroke severity (RR 1.94; 95% CI 1.02-2.87) at 1 year.

Conclusion: Risk factors that predict SAH incidence including hypertension and smoking make outcomes worse. Better management of older patients and those with severe strokes could improve outcomes after SAH.