Countrywide Stroke Incidence, Subtypes, Management and Outcome in a Multiethnic Asian Population: The Singapore Stroke Registry — Methodology

Associated demographic factors for the recurrence and prognosis of stroke patients within a multiethnic Asian population

OBJECTIVE

There is a paucity of studies investigating the outcomes among Asian stroke patients. Identifying subgroups of stroke patients at risk of poorer outcomes could identify patients who would benefit from targeted interventions. Therefore, the aim of this study was to identify which ischemic stroke patients at high risk of recurrent events and mortality.

METHODS

This cohort study adhered to STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines. We obtained data from the Singapore Stroke Registry (SSR) from 2005 to 2016 and cross referenced to the Death Registry and the Myocardial Infarction Registry. Outcome measures included recurrent stroke, acute myocardial infarction (AMI), and all-cause and stroke-related deaths. Multivariable Cox proportional hazards regression models were performed to determine risk factors for recurrent stroke, AMI, and all-cause and stroke-related deaths.

RESULTS

A total of 64,915 patients (6705 young, and 58,210 older) were included in our analysis. Older stroke patients were found to have an increased risk of recurrent stroke (hazard ratio (HR) = 1.21, 95% confidence interval (CI) = 1.12-1.30), AMI (HR = 1.73, 95% CI = 1.54-1.95), all-cause death (HR = 2.49, 95% CI = 2.34-2.64), and stroke-related death (HR = 176, 95% CI = 1.61-1.92). Among young stroke patients, males were at increased risk for recurrent stroke (HR = 1.18, 95% CI = 1.01-1.39) and AMI (HR = 1.41, 95% CI = 1.08-1.83), but at reduced risk for all-cause (HR = 0.78, 95% CI = 0.69-0.89) and stroke-related deaths (HR = 0.79, 95% CI = 0.67-0.94). Ethnicity appeared to influence outcomes, with Malay patients at increased risk of recurrent stroke (HR = 1.37, 95% CI = 1.14-1.65), AMI (HR = 2.45, 95% CI = 1.87-3.22), and all-cause (HR = 1.43, 95% CI = 1.24-1.66) and stroke-related deaths (HR = 1.34, 95% CI = 1.09-1.64). Indian patients were also at increased risk of AMI (HR = 1.96, 95% CI = 1.41-2.72). Similar findings were seen among the older stroke patients.

CONCLUSION

This study found that older stroke patients are at risk of poorer outcomes. Within the young stroke population specifically, males were predisposed to recurrent stroke and AMI but were protected against all-cause and stroke-related deaths. Males were also at reduced risk of all-cause and stroke-related deaths in the older stroke population. In addition, Malay and Indian patients experience poorer outcomes after first stroke. Further optimization of risk factors targeting these high-priority populations are needed to achieve high-quality care.

Incidence and Outcomes of Cardiocerebral Infarction: A Cohort Study of 2 National Population-Based Registries

BACKGROUND

Cardiocerebral infarction (CCI), which is concomitant with acute myocardial infarction (AMI) and acute ischemic stroke (AIS), is a rare but severe presentation. However, there are few data on CCI, and the treatment options are uncertain. We investigated the characteristics and outcomes of CCI compared with AMI or AIS alone.

METHODS

We performed a retrospective cohort study of 120 531 patients with AMI and AIS from the national stroke and AMI registries in Singapore. Patients were categorized into AMI only, AIS only, synchronous CCI (same-day), and metachronous CCI (within 1 week). The primary outcome was all-cause mortality, and the secondary outcome was cardiovascular mortality. The mortality risks were compared using Cox regression. Multivariable models were adjusted for baseline demographics, clinical variables, and treatment for AMI or AIS.

RESULTS

Of 127 919 patients identified, 120 531 (94.2%) were included; 74 219 (61.6%) patients had AMI only, 44 721 (37.1%) had AIS only, 625 (0.5%) had synchronous CCI, and 966 (0.8%) had metachronous CCI. The mean age was 67.7 (SD, 14.0) years. Synchronous and metachronous CCI had a higher risk of 30-day mortality (synchronous: adjusted HR [aHR], 2.41 [95% CI, 1.77-3.28]; metachronous: aHR, 2.80 [95% CI, 2.11-3.73]) than AMI only and AIS only (synchronous: aHR, 2.90 [95% CI, 1.87-4.51]; metachronous: aHR, 4.36 [95% CI, 3.03-6.27]). The risk of cardiovascular mortality was higher in synchronous and metachronous CCI than AMI (synchronous: aHR, 3.03 [95% CI, 2.15-4.28]; metachronous: aHR, 3.41 [95% CI, 2.50-4.65]) or AIS only (synchronous: aHR, 2.58 [95% CI, 1.52-4.36]; metachronous: aHR, 4.52 [95% CI, 2.95-6.92]). In synchronous CCI, AMI was less likely to be managed with PCI and secondary prevention medications (P<0.001) compared with AMI only.

CONCLUSIONS

Synchronous CCI occurred in 1 in 200 cases of AIS and AMI. Synchronous and metachronous CCI had higher mortality than AMI or AIS alone.

Bridging Real-World Data Gaps: Connecting Dots Across 10 Asian Countries

The economic trend and the health care landscape are rapidly evolving across Asia. Effective real-world data (RWD) for regulatory and clinical decision-making is a crucial milestone associated with this evolution. This necessitates a critical evaluation of RWD generation within distinct nations for the use of various RWD warehouses in the generation of real-world evidence (RWE). In this article, we outline the RWD generation trends for 2 contrasting nation archetypes: "Solo Scholars"-nations with relatively self-sufficient RWD research systems-and "Global Collaborators"-countries largely reliant on international infrastructures for RWD generation. The key trends and patterns in RWD generation, country-specific insights into the predominant databases used in each country to produce RWE, and insights into the broader landscape of RWD database use across these countries are discussed. Conclusively, the data point out the heterogeneous nature of RWD generation practices across 10 different Asian nations and advocate for strategic enhancements in data harmonization. The evidence highlights the imperative for improved database integration and the establishment of standardized protocols and infrastructure for leveraging electronic medical records (EMR) in streamlining RWD acquisition. The clinical data analysis and reporting system of Hong Kong is an excellent example of a successful EMR system that showcases the capacity of integrated robust EMR platforms to consolidate and produce diverse RWE. This, in turn, can potentially reduce the necessity for reliance on numerous condition-specific local and global registries or limited and largely unavailable medical insurance or claims databases in most Asian nations. Linking health technology assessment processes with open data initiatives such as the Observational Medical Outcomes Partnership Common Data Model and the Observational Health Data Sciences and Informatics could enable the leveraging of global data resources to inform local decision-making. Advancing such initiatives is crucial for reinforcing health care frameworks in resource-limited settings and advancing toward cohesive, evidence-driven health care policy and improved patient outcomes in the region.

Prehospital stroke care in Singapore

ABSTRACT

Due to the narrow window of opportunity for stroke therapeutics to be employed, effectiveness of stroke care systems is predicated on the efficiency of prehospital stroke systems. A robust prehospital stroke system of care that provides a rapid and well-coordinated response maximises favourable poststroke outcomes, but achieving this presents a unique set of challenges dependent on demographic and geographical circumstances. Set in the context of a highly urbanised first-world nation with a rising burden of stroke, Singapore's prehospital stroke system has evolved to reflect the environment in which it operates. This review aims to characterise the current state of prehospital stroke care in Singapore, covering prehospital aspects of the stroke survival chain from symptom onset till arrival at the emergency department. We identify areas for improvement and innovation, as well as provide insights into the possible future of prehospital stroke care in Singapore.

Trends in hemorrhagic stroke incidence and mortality in a National Stroke Registry of a multi-ethnic Asian population

INTRODUCTION

High-quality epidemiological data on hemorrhagic stroke (HS) and its subtypes, intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), remains limited in Asian ethnicities. We investigated the trends in HS incidence and 30-day mortality from 2005 to 2019 in a multi-ethnic Asian population from a national registry.

PATIENTS AND METHODS

Data on all stroke cases from the Singapore Stroke Registry from 2005 to 2019 were collected. Cases were defined using centrally adjudicated review of diagnosis codes. Death outcomes were obtained by linkage with the national death registry. Incidence (per 100,000 people) and 30-day mortality (per 100 people) were measured as crude and age-standardized rates. Trends were analyzed using linear regression.

RESULTS

We analyzed 19,017 cases of HS (83.9% ICH; 16.1% SAH). From 2005 to 2019, age-standardized incidence rates (ASIR) for HS remained stable from 34.4 to 34.5. However, age-standardized mortality rates (ASMR) decreased significantly from 29.5 to 21.4 (p < 0.001). For ICH, ASIR remained stable while ASMR decreased from 30.4 to 21.3 (p < 0.001); for SAH, ASIR increased from 2.7 to 6.0 (p = 0.006) while ASMR remained stable. In subgroup analyses, HS incidence increased significantly in persons <65 years (from 18.1 to 19.6) and Malays (from 39.5 to 49.7).

DISCUSSION

From 2005 to 2019, ASIR of HS remained stable while ASMR decreased. Decreasing ASMR reflects improvements in the overall management of HS, consistent with global trends.

CONCLUSION

Population health efforts to address modifiable risk factors for HS in specific demographic subgroups may be warranted to reduce incidence and mortality of HS.

Stroke Risk in Survivors of Head and Neck Cancer

Importance

Survivors of head and neck cancers (HNC) have increased risk of stroke. A comprehensive report using standardized methods is warranted to characterize the risk and to inform on survivorship strategy.

Objective

To determine the stroke risk in subpopulations of survivors of HNC in Singapore.

Design, Setting, and Participants

This national, registry-based, cross-sectional study aimed to estimate stroke risk in subgroups of the HNC population between January 2005 and December 2020. Participants were identified from the Singapore Cancer Registry, the Singapore Stroke Registry, and the Registry of Birth and Deaths using relevant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) codes. HNC subgroups were defined based on patient demographic, disease, and treatment factors. Data were analyzed from September 2022 to September 2023.

Exposure

Diagnosis of HNC.

Main Outcomes and Measures

Both ischemic and hemorrhagic stroke were studied. The age-standardized incidence rate ratio (SIRR) and age-standardized incidence rate difference (SIRD) were reported. The Singapore general population (approximately 4 million) served as the reference group for these estimations.

Results

A total of 9803 survivors of HNC (median [IQR] age at diagnosis, 58 [49-68] years; 7166 [73.1%] male) were identified. The most common HNC subsites were nasopharynx (4680 individuals [47.7%]), larynx (1228 individuals [12.5%]), and tongue (1059 individuals [10.8%]). A total of 337 individuals (3.4%) developed stroke over a median (IQR) follow-up of 42.5 (15.0-94.5) months. The overall SIRR was 2.46 (95% CI, 2.21-2.74), and the overall SIRD was 4.11 (95% CI, 3.37-4.85) strokes per 1000 person-years (PY). The cumulative incidence of stroke was 3% at 5 years and 7% at 10 years after HNC diagnosis. The SIRR was highest among individuals diagnosed at younger than 40 years (SIRR, 30.55 [95% CI, 16.24-52.35]). All population subsets defined by age, sex, race and ethnicity, HNC subsites (except tongue), stage, histology, and treatment modalities had increased risk of stroke compared with the general population. The SIRR and SIRD were significantly higher among individuals who had a primary radiation treatment approach (SIRR, 3.01 [95% CI, 2.64-3.43]; SIRD, 5.12 [95% CI, 4.18-6.29] strokes per 1000 PY) compared with a primary surgery approach (SIRR, 1.64 [95% CI, 1.31-2.05]; SIRD, 1.84 [95% CI, 0.923.67] strokes per 1000 PY).

Conclusions and Relevance

In this cross-sectional study of survivors of HNC, elevated stroke risks were observed across different age, subsites, and treatment modalities, underscoring the importance of early screening and intervention.

Non-Hypertensives and Those with Normal Cholesterol Are More Likely to Have Concomitant Cancer amongst Patients with Ischemic Stroke: A Retrospective Cross-Sectional Registry-Based Study

INTRODUCTION

Patients with cancer are known to have an increased risk of ischemic stroke (IS) around the time of their diagnosis. However, there is a paucity of data in Asian populations, and as such, we aimed to determine cancer incidence rates and patterns in Asian IS patients as well as investigate the differences in vascular risk profile of IS patients with and without concomitant cancer.

METHODS

We conducted a retrospective cross-sectional study using data from the Singapore Stroke and Cancer registries. We defined cases as patients with IS and a cancer diagnosis 2 years before or after the index IS. Cancer incidence was determined using the same direct age-standardization method performed for the Singapore general population in the 2015 Singapore cancer report. Multivariable logistic regression was used to analyze differences in vascular risk factors.

RESULTS

Among 21,068 IS patients (mean age, 67.9 ± 13.3 years), 6.3% (1,330) were found to have concomitant cancer; 4.4% (935) had prior cancer while 1.8% (395) had cancer diagnoses within 2 years following IS. The cancer incidence among IS patients was 3,393 (95% confidence interval [CI], 1,937-4,849) per 100,000 person-years compared to 219-231 per 100,000 person-years in the general population. Older age (odds ratio [OR], 1.02 [95% CI, 1.01-1.02] per year), males (OR, 1.25 [95% CI, 1.11-1.41), Chinese ethnicity (OR, 1.61 [95% CI, 1.37-1.89]) and a lower prevalence of hypertension (OR, 0.84 [95% CI, 0.73-0.97)]), and hyperlipidemia (OR, 0.53 [95% CI, 0.45-0.62]) were independently associated with cancer-related IS.

CONCLUSIONS

The age-standardized cancer incidence was 15 times higher in IS patients than the general population. IS patients with concomitant cancer were older and had a lower prevalence of vascular risk factors.

Association of ambient air pollution with risk of hemorrhagic stroke: A time-stratified case crossover analysis of the Singapore stroke registry

BACKGROUND

Haemorrhagic stroke (HS) is a major cause of mortality and disability. Previous studies reported inconsistent associations between ambient air pollutants and HS risk.

OBJECTIVE

We evaluated the association between air pollutant exposure and the risk of HS in a cosmopolitan city in the tropics.

METHODS

We performed a nationwide, population-based, time-stratified case-crossover analysis on all HS cases reported to the Singapore Stroke Registry from 2009 to 2018 (n = 12,636). We estimated the risk of HS across tertiles of air pollutant concentrations in conditional Poisson models, adjusting for meteorological confounders. We stratified our analysis by age, atrial fibrillation and smoking status, and investigated the lagged effects of each pollutant on the risk of HS up to 5 days.

RESULTS

All 12,636 episodes of HS were included. The median (1st-to 3rd-quartile) daily pollutant levels from 22 remote stations deployed across the island were as follows: (PM_2.5 = 15.9 (12.7-20.5), PM₁₀ = 27.3 (22.7-33.4), O₃ = 22.5 (17.3-29.8), NO₂ = 23.3 (18.8-28.4), SO₂ = 10.2 (5.6-14.4), CO = 0.5 (0.5-0.6). The median (1st-to 3rd-quartile) temperature (°C) was 27.9 (27.1-28.7), that of relative humidity (%) was 79.4 (75.6-83.2), and that of total rainfall (mm) was 0.0 (0.0-4.2). Higher levels of CO were significantly associated with an increased risk of HS (3rd tertile vs 1st tertile: Incidence Rate Ratio (IRR) = 1.06, 95% CI = 1.01-1.12). The increased risk of HS due to CO persisted for at least 5 days after exposure. Individuals under 65 years old and non-smokers had a higher risk of HS when exposed to CO. O₃ was associated with increased risk of HS up to 5 days (3rd tertile vs 1st tertile: IRR_{day 1} = 1.07, 95% CI = 1.02-1.12; IRR_{day 5} = 1.07, 95% CI = 1.02-1.13).

CONCLUSION

Short-term exposure to ambient CO levels was associated with an increased risk of HS. A reduction in CO emissions may reduce the burden of HS in the population.

3D-printed external cranial protection following decompressive craniectomy after brain injury: A pilot feasibility cohort study

OBJECTIVES

3D-printed (3DP) customized temporary cranial protection solutions following decompressive craniectomy (DC) are currently not widely practiced. A pilot trial of a 3DP customized head protection prototype device (HPPD) on 10 subjects was conducted during the subacute rehabilitation phase.

MATERIALS AND METHODS

Subjects > 30 days post-DC with stable cranial flaps and healed wounds were enrolled. HPPD were uniquely designed based on individuals' CT scan, where the base conformed to the surface of the individual's skin covering the cranial defect, and the lateral surface three-dimensionally mirrored, the contralateral healthy head. Each HPPD was fabricated using the fused deposition modeling method. These HPPD were then fitted on subjects using a progressive wearing schedule and monitored over 1, 2, 4, 6 and 8 follow-up (FU) weeks. Outcomes during FU included; reported wearing time/day (hours), subjective pain, discomfort, pruritus, dislodgment, cosmesis ratings; and observed wound changes. The primary outcome was safety and tolerability without pain or wound changes within 30 minutes of HPPD fitting.

RESULTS

In all, 10 enrolled subjects received 12 HPPDs [5/10 male, mean (SD) age 46 (14) years, mean (SD) duration post-DC 110 days (76)] and all subjects tolerated 30 minutes of initial HPPD fitting without wound changes. The mean (SD) HPPD mass was 61.2 g (SD 19.88). During 8 weeks of FU, no HPPD-related skin dehiscence was observed, while 20% (2/10) had transient skin imprints, and 80% (8/10) reported self-limiting pressure and pruritis.

DISCUSSION

Findings from this exploratory study demonstrated preliminary feasibility and safety for a customized 3DP HPPD for temporary post-DC head protection over 8 weeks of follow-up. Monitoring and regular rest breaks during HPPD wear were important to prevent skin complications.

CONCLUSION

This study suggests the potential for wider 3DP technology applications to provide cranial protection for this vulnerable population.

Lipid profiles and outcomes of patients with prior cancer and subsequent myocardial infarction or stroke

Patients with cancer are at increased risk of myocardial infarction (MI) and stroke. Guidelines do not address lipid profile targets for these patients. Within the lipid profiles, we hypothesized that patients with cancer develop MI or stroke at lower low density lipoprotein cholesterol (LDL-C) concentrations than patients without cancer and suffer worse outcomes. We linked nationwide longitudinal MI, stroke and cancer registries from years 2007–2017. We identified 42,148 eligible patients with MI (2421 prior cancer; 39,727 no cancer) and 43,888 eligible patients with stroke (3152 prior cancer; 40,738 no cancer). Median LDL-C concentration was lower in the prior cancer group than the no cancer group at incident MI [2.43 versus 3.10 mmol/L, adjusted ratio 0.87 (95% CI 0.85–0.89)] and stroke [2.81 versus 3.22 mmol/L, adjusted ratio 0.93, 95% CI 0.91–0.95)]. Similarly, median triglyceride and total cholesterol concentrations were lower in the prior cancer group, with no difference in high density lipoprotein cholesterol. Prior cancer was associated with higher post-MI mortality [adjusted hazard ratio (HR) 1.48, 95% CI 1.37–1.59] and post-stroke mortality (adjusted HR 1.95, 95% CI 1.52–2.52). Despite lower LDL-C concentrations, patients with prior cancer had worse post-MI and stroke mortality than patients without cancer.

New-Onset Atrial Fibrillation After Cardiac Surgery is a Significant Risk Factor for Long-Term Stroke: An Eight-Year Prospective Cohort Study

OBJECTIVES

This study sought to determine the incidence and significance of new-onset atrial fibrillation as a risk factor for long-term stroke and mortality after cardiac surgery.

DESIGN

A prospective cohort study.

SETTING

Two large tertiary public hospitals.

PARTICIPANTS

The study comprised 3008 patients who underwent coronary artery bypass grafting and/or valve surgery from 2008 to 2012.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

New-onset atrial fibrillation was analyzed as a risk factor for postoperative stroke using a multivariate logistic regression model after adjustment for potential confounders. A Cox regression model with time-dependent variables was used to analyze relationships between new-onset atrial fibrillation and postoperative survival. New-onset atrial fibrillation was detected in 573 (19.0%) patients. Stroke occurred in 234 (7.8%) patients during the mean postoperative follow-up period of six ± two years. The incidence of postoperative stroke in patients with new-onset atrial fibrillation (9.9%) and patients with both preoperative and postoperative atrial fibrillation (13.8%) was higher than in patients with no atrial fibrillation (6.8%) (p = 0.002). New-onset atrial fibrillation (odds ratio, 1.53; 95% confidence interval [CI], 1.08-2.18; p = 0.017) was identified as an independent risk factor for postoperative stroke. A total of 518 (17.2%) mortalities occurred within the mean postoperative follow-up period of eight ± two years. New-onset atrial fibrillation was associated with shorter survival (hazard ratio, 1.49; 95% CI, 1.22-1.81; p < 0.001) compared with patients with no atrial fibrillation.

CONCLUSIONS

New-onset atrial fibrillation is a significant risk factor for long-term stroke and mortality after cardiac surgery. Close monitoring and treatment of this condition may be necessary to reduce the risk of postoperative stroke and mortality.

National Stroke Registry Programme in India for Surveillance and Research: Design and Methodology

The burden of stroke is increasing, and India lacks comparable long-term data on stroke incidence and mortality. Disease surveillance using a registry model can provide long-term data on stroke for linking with public health interventions in stroke prevention, treatment, and rehabilitation. The objectives of the National Stroke Registry Programme (NSRP), India, are to generate reliable data on the incidence of first-ever stroke events in defined populations through a population-based stroke registry (PBSR) and to describe the patterns of care and outcomes of patients with stroke in different treatment settings through a hospital-based stroke registry (HBSR). Continuous systematic collection on a standardized format of diagnostic, treatment, and outcome information on stroke events in persons of defined population (PBSR) and those who attend hospitals (HBSR) is conducted through active data abstraction from review of records from all health facilities and imaging centres that cater to stroke patients. Data are ICD coded, verified, and completed by obtaining survival status of registered patients. IT tools are used for data collection,management and analysis. The NSRP shall establish a standardized stroke surveillance system that would reliably measure stroke incidence, subtypes, treatment patterns, complications, disability, case fatality, and survival. This evidence shall inform health planning of stroke interventions and control activities. It would facilitate improvement in stroke services to improve quality of care and outcomes of stroke. A thrust for research on stroke would be encouraged based on evidence-based hypothesis generation.

Impact of medication nonadherence on stroke recurrence and mortality in patients after first-ever ischemic stroke: Insights from registry data in Singapore

PURPOSE

This retrospective cohort study aims to examine adherence to secondary stroke preventive medications and their association with risk of stroke recurrence and mortality in patients after first-ever ischemic stroke.

METHODS

Using data from the National Healthcare Group and Singapore Stroke Registry, patients with first-ever ischemic stroke between 2010 and 2014 were included, and categorized based on antithrombotic or statin adherence using the proportion of days covered: high (≥75%), intermediate (50%-74%), low (25%-49%), and very low (<25%). The primary outcome was first recurrent ischemic stroke within a year after hospital discharge, while the secondary composite outcomes were (a) stroke recurrence and all-cause mortality and (b) stroke recurrence and cardiovascular mortality. The Cox proportional hazard model was used to examine the association between medication adherence and outcomes. Adjusted hazard ratios (aHRs) and the corresponding 95% confidence intervals (CIs) were reported.

RESULTS

Among ischemic stroke patients prescribed with antithrombotics (n = 1139) or statins (n = 1160) at hospital discharge, about one-third were highly adherent to their medications. Patients with lower medication adherence tended to be younger, were admitted to private ward classes, and were without hypertension. Compared with the patients with high medication adherence, the risk of stroke recurrence was higher in patients with very low antithrombotic (aHR = 4.65; 95% CI: 1.45-14.89) or statin (aHR = 3.44; 95% CI: 0.93-12.74) adherence. Similar findings were observed for the secondary outcomes.

CONCLUSIONS

Poor adherence to antithrombotic and statin treatment increases the risk of recurrent stroke and mortality in patients after first-ever ischemic stroke. Further measures are needed to improve medication adherence among stroke survivors.

Post-stroke patients with moderate function have the greatest risk of falls: a National Cohort Study

BACKGROUND

Stroke patients have increased risks of falls. We examined national registry data to evaluate the association between post-stroke functional level and the risk of low falls among post-stroke patients.

METHODS

This retrospective cohort study analyzed data from national registries to examine the risk factors for post-stroke falls. Data for patients who suffered ischemic strokes and survived the index hospital admission was obtained from the Singapore National Stroke Registry and matched to the National Trauma Registry, from 2011 to 2015. The primary outcome measure was a low fall (fall height ≤ 0.5 m). Competing risk analysis was performed to examine the association between functional level (by modified Rankin score [mRS] at discharge) and the risk of subsequent low falls.

RESULTS

In all, 2255 patients who suffered ischemic strokes had recorded mRS. The mean age was 66.6 years and 58.5% were men. By the end of 2015, 54 (2.39%) had a low fall while 93 (4.12%) died. After adjusting for potential confounders, mRS was associated with fall risk with an inverted U-shaped relationship. Compared to patients with a score of zero, the sub-distribution hazard ratio (SHR) increased to a maximum of 3.42 (95%CI:1.21-9.65, p = 0.020) for patients with a score of 2. The SHR then declined to 2.45 (95%CI:0.85-7.12, p = 0.098), 2.86 (95%CI:0.95-8.61, p = 0.062) and 1.93 (95%CI:0.44-8.52, p = 0.38) for patients with scores of 3, 4 and 5 respectively.

CONCLUSIONS

An inverted U-shaped relationship between functional status and fall risk was observed. This is consistent with the complex interplay between decreasing mobility (hence decreased opportunity to fall) and increasing susceptibility to falls. Fall prevention intervention could be targeted accordingly. (263 words).

Stroke Factors Associated with Thrombolysis Use in Hospitals in Singapore and US: A Cross-Registry Comparative Study

BACKGROUND AND OBJECTIVES

This paper aims to describe and compare the characteristics of 2 stroke populations in Singapore and in St. Louis, USA, and to document thrombolysis rates and contrast factors associated with its uptake in both populations.

METHODS

The stroke populations described were from the Singapore Stroke Registry (SSR) in -Singapore and the Cognitive Rehabilitation Research Group Stroke Registry (CRRGSR) in St. Louis, MO, USA. The registries were compared in terms of demographics and stroke risk factor history. Logistic regression was used to determine factors associated with thrombolysis uptake.

RESULTS

A total of 39,323 and 8,106 episodes were recorded in SSR and CRRGSR, respectively, from 2005 to 2012. Compared to CRRGSR, patients in SSR were older, male, and from the ethnic majority. Thrombolysis rates in SSR and CRRGSR were 2.5 and 8.2%, respectively, for the study period. History of ischemic heart disease or atrial fibrillation was associated with increased uptake in both populations, while history of stroke was associated with lower uptake. For SSR, younger age and males were associated with increased uptake, while having a history of smoking or diabetes was associated with decreased uptake. For CRRGSR, ethnic minority status was associated with decreased uptake.

CONCLUSIONS

The comparison of stroke populations in Singapore and St Louis revealed distinct differences in clinicodemographics of the 2 groups. Thrombolysis uptake was driven by nonethnicity demographics in Singapore. Ethnicity was the only demographic driver of uptake in the CRRGSR population, highlighting the need to target ethnic minorities in increasing access to thrombolysis.

Temporal Trends and Predictors of Drug Utilization and Outcomes in First-Ever Stroke Patients: A Population-Based Study Using the Singapore Stroke Registry

INTRODUCTION

Drug utilization and outcomes research in multi-ethnic Asian stroke populations is lacking.

OBJECTIVES

Our objective was to examine temporal trends and predictors of drug utilization and outcomes in a multi-ethnic Asian stroke population.

METHODS

This registry-based study included ischemic and hemorrhagic first-ever stroke patients hospitalized between 2009 and 2016. Utilization of medications included in-hospital thrombolytic agents, early antithrombotics (antiplatelets, anticoagulants) within 48 h of admission, and antithrombotics and statins at discharge. Outcomes analyzed were in-hospital all-cause mortality; 28-day, 90-day, and 1-year case fatality (CF); and discharge destination.

RESULTS

Of the 36,615 included patients, 81.6% had ischemic stroke and 18.4% had hemorrhagic stroke (15.5% intracerebral hemorrhage [ICH] and 2.8% subarachnoid hemorrhage [SAH]). For ischemic stroke, the combined use of all three guideline medications (in-hospital thrombolytic therapy, as well as antithrombotics and statins at discharge) increased (P = 0.006). Being on the stroke pathway was associated with prescription of all three guideline medications in ischemic stroke. Decreasing trends for in-hospital mortality, 28-day, 90-day, and 1-year CF and proportion of patients discharged home without rehabilitation appointment were observed in ischemic stroke (P < 0.05) but not in ICH or SAH (apart from 28-day CF). Ischemic stroke patients who received guideline medications were less likely to die or be discharged to nursing homes and chronic sick hospitals. Hemorrhagic stroke patients prescribed statins at discharge were less likely to have 28-day and 1-year CF.

CONCLUSIONS

Prescription of secondary stroke preventive medications (particularly in ischemic stroke) was associated with more favorable outcomes, highlighting the importance of physician adherence to evidence-based pharmacotherapy.

Comparative analysis of recurrent events after presentation with an index myocardial infarction or ischaemic stroke

Aims

Acute myocardial infarction (AMI) and stroke are important causes of mortality and morbidity. Our aims are to determine the comparative epidemiology of AMI and ischaemic stroke; and examine the differences in cardiovascular outcomes or mortality occurring after an AMI or stroke.

Methods and results

The Singapore National Registry of Diseases Office collects countrywide data on AMI, stroke, and mortality. Index events of AMI and ischaemic stroke between 2007 and 2012 were identified. Patients were then matched for occurrences of subsequent AMI, stroke, or death within 1-year of the index event. There were 33 222 patients with first-ever AMI and 20 982 with first-ever stroke. AMI patients were significantly more likely to be men (66.3% vs. 56.9%), non-Chinese (32.1% vs. 24.1%), and smokers (43.1% vs. 38.6%), but less likely to have hypertension (65.6% vs. 79%) and hyperlipidaemia (61.1% vs. 65.5%), compared with stroke patients. In total 6.8% of the AMI patients had recurrent AMI, whereas 4.8% of the stroke patients had recurrent stroke within 1 year; 31.7% of the AMI patients died, whereas 17.1% of the ischaemic stroke patients died within 1 year. Older age, Malay ethnicity, and diabetes mellitus were statistically significant risk factors for all-cause mortality and for the composite endpoint of AMI, stroke, and all-cause mortality, at 1 year.

Conclusions

Risk profiles of patients with AMI and stroke are significantly different. Patients suffer recurrent events in vascular territories similar to the index event. Age and diabetes mellitus are significant predictors of recurrent vascular events and mortality.

The Relationship Between Ambient Air Pollution and Acute Ischemic Stroke: A Time-Stratified Case-Crossover Study in a City-State With Seasonal Exposure to the Southeast Asian Haze Problem

STUDY OBJECTIVE

Studies are divided on the short-term association of air pollution with stroke. Singapore is exposed to seasonal transboundary haze. We aim to investigate the association between air pollution and stroke incidence in Singapore.

METHODS

We performed a time-stratified case-crossover analysis on all ischemic stroke cases reported to the Singapore Stroke Registry from 2010 to 2015. Exposure on days was compared with control days on which exposure did not occur. Control days were chosen on the same day of the week earlier and later in the same month in the same year. We fitted a conditional Poisson regression model to daily stroke incidence that included Pollutant Standards Index and environmental confounders. The index was categorized according to established classification (0 to 50=good, 51 to 100=moderate, and ≥101=unhealthy). We assessed the relationship between stroke incidence and Pollutant Standards Index in the entire cohort and in predetermined subgroups of individual-level characteristics.

RESULTS

There were 29,384 ischemic stroke cases. Moderate and unhealthy Pollutant Standards Index levels showed association with stroke occurrence, with incidence risk ratio 1.10 (95% confidence interval 1.06 to 1.13) and 1.14 (95% confidence interval 1.03 to 1.25), respectively. Subgroup analyses showed generally significant association, except in Indians and nonhypertensive patients. The association was significant in subgroups aged 65 years or older, women, Chinese, nonsmokers and those with history of diabetes, hypertension, and hyperlipidemia. Stratified by age and smoking, the risk diminished in smokers of all ages. Risk remained elevated for 5 days after exposure.

CONCLUSION

We found a short-term elevated risk of ischemic stroke after exposure to air pollution. These findings have public health implications for stroke prevention and emergency health services delivery.

National stroke registries for monitoring and improving the quality of hospital care: A systematic review

Background

Routine monitoring of the quality of stroke care is becoming increasingly important since patient outcomes could be improved with better access to proven treatments. It remains unclear how many countries have established a national registry for monitoring stroke care.

Aims

To describe the current status of national, hospital-based stroke registries that have a focus on monitoring access to evidence-based care and patient outcomes and to summarize the main features of these registries.

Summary of review

We undertook a systematic search of the published literature to identify the registries that are considered in their country to represent a national standardized dataset for acute stroke care and outcomes. Our initial keyword search yielded 5002 potential papers, of which we included 316 publications representing 28 national stroke registries from 26 countries. Where reported, data were most commonly collected with a waiver of patient consent (70%). Most registries used web-based systems for data collection (57%) and 25% used data linkage. Few variables were measured consistently among the registries reflecting their different local priorities. Funding, resource requirements, and coverage also varied.

Conclusions

This review provides an overview of the current use of national stroke registries, a description of their common features relevant to monitoring stroke care in hospitals. Formal registration and description of registries would facilitate better awareness of efforts in this field.

Trends in Stroke Incidence and 28-Day Case Fatality in a Nationwide Stroke Registry of a Multiethnic Asian Population

Background and Purpose—

This study investigated trends in stroke incidence and case fatality overall and according to sex, age, ethnicity, and stroke subtype in a multiethnic Asian population.

Methods—

The Singapore Stroke Registry identifies all stroke cases in all public hospitals using medical claims, hospital discharge summaries, and death registry data. Age-standardized incidence rates and 28-day case-fatality rates were calculated for individuals aged ≥15 years between 2006 and 2012. To estimate the annual percentage change of the rates, a linear regression model was fitted to the log rates, and a Wald test was performed to test for trend. P values <0.05 were considered significant.

Results—

A total of 40 623 cases were recorded. The total stroke incidence fell by ≈12.0%, and case fatality fell by 17.2% in the study. Declining trends in stroke incidence were stronger in women (female: −2.94; 95% confidence interval [CI], −3.43 to −2.44; male: −1.80; 95% CI, −2.58 to −1.02); in the older age groups (≥65 years: −3.62; 95% CI, −4.30 to −2.94; 50–64 years: −1.26; 95% CI, −1.97 to −0.55; <50 years: 3.33; 95% CI, 1.49 to 5.20), in Chinese (−2.64; 95% CI, −3.15 to −2.13), Indians (−3.78; 95% CI, −5.93 to −1.58), and others (−12.73; 95% CI, −18.93 to −6.06) compared with Malays (2.58; 95% CI, 1.17 to 4.02); and in ischemic stroke subtype (ischemic: −2.43; 95% CI, −3.13 to −1.73; hemorrhagic: −1.02; 95% CI, −2.04 to 0.01). Subgroup-specific findings for case fatality were similar.

Conclusion—

This is the first countrywide hospital-based registry study in a multiethnic Asian population, and it revealed marked overall reductions in stroke incidence and case fatality. However, it also identified important population groups with less favorable trends, especially younger adults and those of Malay ethnicity.