Validity of a stroke severity index for administrative claims data research: a retrospective cohort study

Use of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers Is Associated With a Reduced Risk of Poststroke Epilepsy in Patients With Ischemic Stroke

BACKGROUND

Poststroke epilepsy (PSE) is a common complication after ischemic stroke. This study investigates the association between the use of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) and the risk of PSE in patients with ischemic stroke.

METHODS AND RESULTS

A population-based retrospective cohort study was conducted using Taiwan's National Health Insurance Research Database between 2000 and 2015. Patients with hypertension with a history of ischemic stroke were classified into prevalent, new, and nonusers according to their use of ACEIs/ARBs. Prevalent ACEI/ARB users were further classified into continuing or discontinued users, based on their poststroke medication adherence. We used multivariate Cox regression models, adjusted for demographics and comorbidities, to assess the risk of PSE among different ACEI/ARB user groups. There were 182 983 ACEI/ARB users and 38 365 nonusers included. There were 7387 patients diagnosed with PSE, whereas 213 961 were not. Nonusers exhibited a higher risk of PSE (adjusted hazard ratio [aHR], 1.72 [95% CI, 1.63-1.82]). Both prevalent and nonusers had higher risks compared with new ACEI/ARB users, with respective aHRs of 1.33 (95% CI, 1.25-1.41) and 2.00 (95% CI, 1.87-2.14). Discontinued ACEI/ARB users showed the highest risk of PSE (aHR, 2.34 [95% CI, 2.15-2.54]), suggesting the importance of continuing ACEI/ARB use after stroke. Treatment-by-age interaction was significant among patients with or without ACEI/ARB use before stroke (P value for interaction 0.004 and <0.001, respectively), suggesting a stronger beneficial association in younger patients.

CONCLUSIONS

The use of ACEIs/ARBs after ischemic stroke in patients with hypertension is associated with a reduced risk of PSE, especially among younger patients.

Prognosis of Patients With Ischemic Stroke With Prior Anticoagulant Therapy: Direct Oral Anticoagulants Versus Warfarin

BACKGROUND

Direct oral anticoagulants (DOACs) have been the drug of choice for preventing ischemic stroke in patients with atrial fibrillation since 2014. In previous studies, the stroke risk while taking warfarin was 2 per 100 patient-years and 1.5% per year while taking DOACs. We hypothesized that even if ischemic stroke occurred during anticoagulation therapy with DOACs, the prognosis was likely to be better than that with warfarin.

METHODS AND RESULTS

Data from 2002 to 2019, sourced from a nationwide claims database, were used to identify atrial fibrillation patients using International Classification of Diseases codes. Patients who experienced an ischemic stroke during anticoagulation were categorized by the drugs used (warfarin, dabigatran, apixaban, rivaroxaban, and edoxaban). The primary outcome was mortality within 3 months and 1 year after the ischemic stroke. Among the 9578 patients with ischemic stroke during anticoagulation, 3343 received warfarin, and 6235 received DOACs (965 dabigatran, 2320 apixaban, 1702 rivaroxaban, 1248 edoxaban). The DOACs group demonstrated lower risks of 3-month (adjusted hazard ratio [HR], 0.550, [95% CI, 0.473-0.639]; P<0.0001) and 1-year mortality (adjusted HR, 0.596 [95% CI, 0.536-0.663]; P<0.0001) than the warfarin group. Apixaban and edoxaban within the DOAC group exhibited particularly reduced 1-year mortality risk compared with other DOACs (P<0.0001).

CONCLUSIONS

Our study confirmed that DOACs have a better prognosis than warfarin after ischemic stroke. The apixaban and edoxaban groups had a lower risk of death after ischemic stroke than the other DOAC groups.

The association between antithrombotic drug regimen changes and clinical outcomes after stroke in atrial fibrillation

BACKGROUND

The impact of post-stroke antithrombotic regimen in atrial fibrillation (AF) is uncertain.

OBJECTIVE

To describe antithrombotic therapy prescribing patterns following ischemic stroke, and its impact on outcomes.

METHODS

A total of 23,165 AF patients experiencing ischemic stroke were identified. Subsequent post-stroke events included recurrent ischemic stroke, intracranial hemorrhage (ICH), major bleeding, mortality, and composite outcomes.

RESULTS

Among those who were non-anticoagulated before a stroke, 33.5% remained non-anticoagulated and 39.2% were prescribed only antiplatelets (AP) post-stroke. Compared to NOACs post-stroke, there was a significant increase in ischemic stroke and mortality in non-anticoagulated (aHRs 2.09 and 3.92) and antiplatelet users (aHRs 1.32 and 1.28). Post-stroke warfarin was associated with a significantly incresaed risk of major bleeding compared to NOACs (aHR 1.23). Among 769 patients receiving NOACs before stroke and continuing NOAC post-stroke, those switching to a different NOAC were associated with significantly higher risk of ischemic stroke (aHR 2.07) and composite outcomes (aHRs 1.36-1.85) with no difference in ICH, major bleeding or mortality compared to those on the same NOAC post-stroke. Among patients receiving NOACs before stroke, the risks of clinical events were similar between patients on NOACs alone and those on NOAC plus AP post-stroke.

CONCLUSIONS

NOAC alone post-stroke was associated with a better clinical outcome compared to non-anticoagulation, AP or warfarin. Among patients already taking NOACs before stroke, the addition of AP didn't confer additional benefits compared to NOACs alone. A change of NOAC types post-stroke was associated with a two-fold higher risk of ischemic stroke and composite outcomes.

Assessment of the impact of resting heart rate on the risk of major adverse cardiovascular events after ischemic stroke: a retrospective observational study

BACKGROUND

Although elevated heart rate is a risk factor for cardiovascular morbidity and mortality in healthy people, the association between resting heart rate and major cardiovascular risk in patients after acute ischemic stroke remains debated. This study evaluated the association between heart rate and major adverse cardiovascular events after ischemic stroke.

METHODS

We conducted a retrospective cohort study analyzing data from the Chang Gung Research Database for 21,655 patients with recent ischemic stroke enrolled between January 1, 2010, and September 30, 2018. Initial in-hospital heart rates were averaged and categorized into 10-beats per minute (bpm) increments. The primary outcome was the composite of hospitalization for recurrent ischemic stroke, myocardial infarction, or all-cause mortality. Secondary outcomes were hospitalization for recurrent ischemic stroke, myocardial infarction, and heart failure. Hazard ratios and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models, using the heart rate < 60 bpm subgroup as the reference.

RESULTS

After a median follow-up of 3.2 years, the adjusted hazard ratios for the primary outcome were 1.13 (95% CI: 1.01 to 1.26) for heart rate 60-69 bpm, 1.35 (95% CI: 1.22 to 1.50) for heart rate 70-79 bpm, 1.64 (95% CI: 1.47 to 1.83) for heart rate 80-89 bpm, and 2.08 (95% CI: 1.85 to 2.34) for heart rate ≥ 90 bpm compared with the reference group. Heart rate ≥ 70 bpm was associated with increased risk of all secondary outcomes compared with the reference group except heart failure.  CONCLUSIONS: Heart rate is a simple measurement with important prognostic implications. In patients with ischemic stroke, initial in-hospital heart rate was associated with major adverse cardiovascular events.

Association between repeat imaging and readmission in patients with acute ischaemic stroke: a 16-year nationwide population-based study

OBJECTIVES

This study aims to evaluate such usage patterns and identify factors that may contribute to the need for repeat imaging in acute ischaemic stroke patients and determine the association between repeat imaging and readmission in Taiwan.

METHODS

We searched and analysed data from the Taiwan National Health Insurance Research Database for patients admitted for acute ischaemic stroke between 2002 and 2017. Cases where repeat brain imaging during the initial hospital admission occurred and where patients were readmitted within 30 days following discharge were documented.

RESULTS

Of a total of 195 016 patients with new onset ischaemic stroke, 51 798 (26.6%) underwent repeat imaging during their initial admission. Factors associated with repeat brain imaging included younger age, longer hospital stay, use of recombinant tissue plasminogen activator (rt-PA) therapy (odds ratio = 2.10 [95% CI, 1.98-2.22]), more recent year of diagnosis, higher National Institutes of Health Stroke Scale (NIHSS) score, and admission to a hospital offering a higher level of care. Repeat imaging was also associated with an increased risk of ischaemic stroke and all types of stroke readmission.

CONCLUSIONS

Repeat brain imaging of patients with stroke has increased in recent years, and it is associated with certain factors including age, length of stay, use of rt-PA, hospital level of care, and NIHSS score. It is also associated with increased readmission.

ADVANCES IN KNOWLEDGE

Knowledge of the associations of repeat imaging may help clinicians use repeat imaging more carefully and efficaciously.

Cilostazol plus Aspirin vs. Clopidogrel plus Aspirin in Acute Minor Stroke or Transient Ischemic Attack

AIM

This study compared the effectiveness, safety, and mortality risks between cilostazol plus aspirin and clopidogrel plus aspirin treatment for patients with acute minor ischemic stroke or transient ischemic attack (TIA).

METHODS

This retrospective cohort study employed a new-user design and utilized data from the nationwide Health and Welfare Database in Taiwan. Patients were included if they were discharged with newly initiated cilostazol plus aspirin or clopidogrel plus aspirin after primary acute minor ischemic stroke or TIA hospitalization between 2009 and 2018. Inverse probability of treatment weighting was applied to balance covariats between study groups. Effectiveness outcomes were the risks of acute ischemic stroke, acute myocardial infarction (AMI), TIA, and composite cardiovascular events; Safety outcomes were the risks of intracranial hemorrhage (ICH), gastrointestinal bleeding, and composite bleeding events; Mortality outcomes were the risks of fatal stroke, cardiovascular mortality, and all-cause mortality.

RESULTS

A total of 3,403 patients were included, of which 578 were treated with cilostazol plus aspirin and 2,825 were treated with clopidogrel plus aspirin. Cilostazol plus aspirin was associated with a higher risk of ICH (HR: 1.82; 95% CI: 1.16-2.84) compared to clopidogrel plus aspirin. No significant differences in the risks of effectiveness or mortality outcomes between the two groups were found.

CONCLUSIONS

The effectiveness and mortality of the two groups were similar for patients with acute minor ischemic stroke or TIA. However, cilostazol plus aspirin was associated with a higher risk of ICH compared to clopidogrel plus aspirin. Patients treated with cilostazol plus aspirin among this population should be monitored carefully to ensure their safety.

Characteristics and risk of stroke in emergency department patients with acute dizziness

Background

Acute dizziness is a common symptom in the emergency department (ED), with strokes accounting for 3 %-5 % of cases. We investigated the risk of stroke in ED patients with acute dizziness and compared stroke characteristics diagnosed during and after the ED visit.

Methods

We identified adult patients with acute dizziness, vertigo, or imbalance using a hospital research-based database. Patients with abdominal or flank pain were used as the comparison group. Patients with dizziness were 1:1 matched to comparison patients. Each patient was traced for up to one year until being hospitalized for a stroke.

Results

Out of the 24,266 eligible patients, 589 (2.4 %) were hospitalized for stroke during the ED visit. For the remaining 23,677 patients, the risk of stroke at 7, 30, 90, and 365 days after ED discharge was 0.40 %, 0.52 %, 0.71 %, and 1.25 % respectively. Patients with dizziness had a higher risk of stroke compared to the comparison group at 7, 30, 90, and 365 days. The risk ratios decreased from 5.69 (95 % confidence interval [CI], 3.34-9.68) to 2.03 (95 % CI, 1.65-2.49). Compared to patients hospitalized for stroke during the ED visit, those hospitalized for stroke after the ED visit had greater stroke severity despite a lower initial triage acuity. Patients with early stroke (≤7 days) after ED discharge were less likely to have hypertension, diabetes, hyperlipidemia, and atrial fibrillation. They mostly experienced posterior circulation stroke. Patients with late stroke (>7 days) were older and less likely to have hypertension and hyperlipidemia but more likely to have a history of prior stroke and ischemic heart disease. Their strokes were mainly located in the anterior circulation territory.

Conclusions

The risk of stroke after ED discharge was higher in patients with dizziness than in the comparison group, with gradually decreasing risk ratios in the following year. Patients hospitalized for stroke during and after the ED visit had different profiles of vascular risk factors and clinical characteristics.

Dual Antithrombotic Therapy versus Anticoagulant Monotherapy for Major Adverse Limb Events in Patients with Concomitant Lower Extremity Arterial Disease and Atrial Fibrillation: A Propensity Score Weighted Analysis

OBJECTIVE

Patients with symptomatic lower extremity arterial disease (LEAD) are recommended to receive antiplatelet therapy, while direct oral anticoagulants (DOACs) are standard for stroke prevention in patients with atrial fibrillation (AF). For patients with concomitant LEAD and AF, data comparing dual antithrombotic therapy (an antiplatelet agent used in conjunction with a DOAC) vs. DOAC monotherapy are scarce. This retrospective cohort study, based on data from the Taiwan National Health Insurance Research Database, aimed to compare the efficacy and safety of these antithrombotic strategies.

METHODS

Patients with AF who underwent revascularisation for LEAD between 2012 - 2020 and received any DOAC within 30 days of discharge were included. Patients were grouped by antiplatelet agent exposure into the dual antithrombotic therapy and DOAC monotherapy groups. Inverse probability of treatment weighting was used to mitigate selection bias. Major adverse limb events (MALEs), ischaemic stroke or systemic embolism, and bleeding outcomes were compared. Patients were followed until the occurrence of any study outcome, death, or up to two years.

RESULTS

A total of 1 470 patients were identified, with 736 in the dual antithrombotic therapy group and 734 in the DOAC monotherapy group. Among them, 1 346 patients received endovascular therapy as the index revascularisation procedure and 124 underwent bypass surgery. At two years, dual antithrombotic therapy was associated with a higher risk of MALEs than DOAC monotherapy (subdistribution hazard ratio [SHR] 1.34, 95% confidence interval [CI] 1.15 - 1.56), primarily driven by increased repeat revascularisation. Dual antithrombotic therapy was also associated with a higher risk of major bleeding (SHR 1.43, 95% CI 1.05 - 1.94) and gastrointestinal bleeding (SHR 2.17, 95% CI 1.42 - 3.33) than DOAC monotherapy.

CONCLUSION

In patients with concomitant LEAD and AF who underwent peripheral revascularisation, DOAC monotherapy was associated with a lower risk of MALEs and bleeding events than dual antithrombotic therapy.

Risk of Bleeding Following Non-Vitamin K Antagonist Oral Anticoagulant Use in Patients With Acute Ischemic Stroke Treated With Alteplase

Importance

Current guidelines advise against intravenous alteplase therapy for treatment of acute ischemic stroke in patients previously treated with non-vitamin K antagonist oral anticoagulants (NOACs).

Objective

To evaluate the risk of bleeding and mortality after alteplase treatment for acute ischemic stroke among patients treated with NOACs compared to those not treated with NOACs.

Design, Setting, and Participants

This nationwide, population-based cohort study was conducted in Taiwan using data from Taiwan's National Health Insurance Research Database from January 2011 through November 2020 and included 7483 patients treated with alteplase for acute ischemic stroke. A meta-analysis incorporating the results of the study with those of previous studies was performed, and the review protocol was prospectively registered with PROSPERO.

Exposures

NOAC treatment within 2 days prior to stroke, compared to either no anticoagulant treatment or warfarin treatment.

Main Outcomes and Measures

The primary outcome was intracranial hemorrhage after intravenous alteplase during the index hospitalization (the hospitalization subsequent to alteplase administration). Secondary outcomes were major bleeding events and mortality during the index hospitalization. Propensity score matching was used to control potential confounders. Logistic regression was used to estimate the odds ratio (OR) of outcome events. Meta-analysis was performed using a random-effects model.

Results

Of the 7483 included patients (mean [SD] age, 67.4 [12.7] years; 2908 [38.9%] female individuals and 4575 [61.1%] male individuals), 91 (1.2%), 182 (2.4%), and 7210 (96.4%) received NOACs, warfarin, and no anticoagulants prior to their stroke, respectively. Compared to patients who were not treated with anticoagulants, those treated with NOACs did not have significantly higher risks of intracranial hemorrhage (risk difference [RD], 2.47% [95% CI, -4.23% to 9.17%]; OR, 1.37 [95% CI, 0.62-3.03]), major bleeding (RD, 4.95% [95% CI, -2.56% to 12.45%]; OR, 1.69 [95% CI, 0.83-3.45]), or in-hospital mortality (RD, -4.95% [95% CI, -10.11% to 0.22%]; OR, 0.45 [95% CI, 0.15-1.29]) in the propensity score-matched analyses. Furthermore, the risks of bleeding and mortality were not significantly different between patients treated with NOACs and those treated with warfarin. Similar results were obtained in the meta-analysis.

Conclusions and Relevance

In this cohort study with meta-analysis, compared to no treatment with anticoagulants, treatment with NOACs prior to stroke was not associated with a higher risk of intracranial hemorrhage, major bleeding, or mortality in patients receiving intravenous alteplase for acute ischemic stroke.

External Validation and Recalibration of a Mortality Prediction Model for Patients with Ischaemic Stroke

BACKGROUND

Stroke is a highly prevalent disease that can provoke severe disability. We evaluate a predictive model based on the Minimum Basic Data Set (MBDS) compiled by the Spain Health Ministry, obtained for the period 2008-2012 for patients with ischaemic stroke in Spain, to establish the model's validity and to optimise its calibration. The MBDS is the main clinical-administrative database for hospitalisations recorded in Spain, and to our knowledge, no predictive models for stroke mortality have previously been developed using this resource. The main study aim is to perform an external validation and recalibration of the coefficients of this predictive model with respect to a chronologically later cohort.

MATERIAL AND METHODS

External validation (testing the model on a different cohort to assess its performance) and recalibration (validation with optimisation of model coefficients) were performed using the MBDS for patients admitted for ischaemic stroke in the period 2016-2018. A cohort study was designed, in which a recalibrated model was obtained by applying the variables of the original model without their coefficients. The variables from the original model were then applied to the subsequent cohort, together with the coefficients from the initial model. The areas under the curve (AUC) of the recalibration and the external validation procedure were compared.

RESULTS

The recalibrated model produced an AUC of 0.743 and was composed of the following variables: age (odds ratio, OR:1.073), female sex (OR:1.143), ischaemic heart disease (OR:1.192), hypertension (OR:0.719), atrial fibrillation (OR:1.414), hyperlipidaemia (OR:0.652), heart failure (OR:2.133) and posterior circulation stroke (OR: 0.755). External validation produced an AUC of 0.726.

CONCLUSIONS

The recalibrated clinical model thus obtained presented moderate-high discriminant ability and was generalisable to predict death for patients with ischaemic stroke. Rigorous external validation slightly decreased the AUC but confirmed the validity of the baseline model for the chronologically later cohort.

Weekend effect on 30-day mortality for ischemic and hemorrhagic stroke analyzed using severity index and staffing level

BACKGROUND AND PURPOSE

Previous studies on the weekend effect-a phenomenon where stroke outcomes differ depending on whether the stroke occurred on a weekend-mostly targeted ischemic stroke and showed inconsistent results. Thus, we investigated the weekend effect on 30-day mortality in patients with ischemic or hemorrhagic stroke considering the confounding effect of stroke severity and staffing level.

METHODS

We retrospectively analyzed data of patients hospitalized for ischemic or hemorrhagic stroke between January 1, 2015, and December 31, 2018, which were extracted from the claims database of the National Health Insurance System and the Medical Resource Report by the Health Insurance Review & Assessment Service. The primary outcome measure was 30-day all-cause mortality.

RESULTS

In total, 278,632 patients were included, among whom 84,240 and 194,392 had a hemorrhagic and ischemic stroke, respectively, with 25.8% and 25.1% of patients, respectively, being hospitalized during the weekend. Patients admitted on weekends had significantly higher 30-day mortality rates (hemorrhagic stroke 16.84%>15.55%, p<0.0001; ischemic stroke 5.06%>4.92%, p<0.0001). However, in the multi-level logistic regression analysis adjusted for case-mix, pre-hospital, and hospital level factors, the weekend effect remained consistent in patients with hemorrhagic stroke (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.00-1.10), while the association was no longer evident in patients with ischemic stroke (OR 1.01, 95% CI 0.96-1.06).

CONCLUSIONS

Weekend admission for hemorrhagic stroke was significantly associated with a higher mortality rate after adjusting for confounding factors. Further studies are required to understand factors contributing to mortality during weekend admission.

Association between initial in-hospital heart rate and glycemic control in patients with acute ischemic stroke and diabetes mellitus

BACKGROUND

A high resting heart rate (HR) has been associated with an increased risk of diabetes mellitus. This study explored the association between initial in-hospital HR and glycemic control in patients with acute ischemic stroke (AIS) and diabetes mellitus.

METHODS

We analyzed data from 4,715 patients with AIS and type 2 diabetes mellitus enrolled in the Chang Gung Research Database between January 2010 and September 2018. The study outcome was unfavorable glycemic control, defined as glycated hemoglobin (HbA1c) ≥ 7%. In statistical analyses, the mean initial in-hospital HR was used as both a continuous and categorical variable. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression analysis. The associations between the HR subgroups and HbA1c levels were analyzed using a generalized linear model.

RESULTS

Compared with the reference group (HR < 60 bpm), the adjusted ORs for unfavorable glycemic control were 1.093 (95% CI 0.786-1.519) for an HR of 60-69 bpm, 1.370 (95% CI 0.991-1.892) for an HR of 70-79 bpm, and 1.608 (95% CI 1.145-2.257) for an HR of ≥ 80 bpm. Even after adjusting for possible confounders, the HbA1c levels after admission and discharge among diabetic stroke patients increased significantly in the subgroups with higher HRs (p < 0.001).

CONCLUSIONS

High initial in-hospital HR is associated with unfavorable glycemic control in patients with AIS and diabetes mellitus, particularly in those with an HR of ≥ 80 bpm, compared with those with an HR of < 60 bpm.

Development and Validation of a Novel Score for Predicting Long-Term Mortality after an Acute Ischemic Stroke

BACKGROUND

Long-term mortality prediction can guide feasible discharge care plans and coordinate appropriate rehabilitation services. We aimed to develop and validate a prediction model to identify patients at risk of mortality after acute ischemic stroke (AIS).

METHODS

The primary outcome was all-cause mortality, and the secondary outcome was cardiovascular death. This study included 21,463 patients with AIS. Three risk prediction models were developed and evaluated: a penalized Cox model, a random survival forest model, and a DeepSurv model. A simplified risk scoring system, called the C-HAND (history of Cancer before admission, Heart rate, Age, eNIHSS, and Dyslipidemia) score, was created based on regression coefficients in the multivariate Cox model for both study outcomes.

RESULTS

All experimental models achieved a concordance index of 0.8, with no significant difference in predicting poststroke long-term mortality. The C-HAND score exhibited reasonable discriminative ability for both study outcomes, with concordance indices of 0.775 and 0.798.

CONCLUSIONS

Reliable prediction models for long-term poststroke mortality were developed using information routinely available to clinicians during hospitalization.

Initial In-Hospital Visit-to-Visit Heart Rate Variability Is Associated with Higher Risk of Atrial Fibrillation in Patients with Acute Ischemic Stroke

BACKGROUND

To evaluate the association between the visit-to-visit heart rate variability and the risk of atrial fibrillation (AF) in acute ischemic stroke (AIS).

METHODS

We analyzed the data of 8179 patients with AIS. Patients without AF on 12-lead electrocardiography underwent further 24 h Holter monitoring. They were categorized into four subgroups according to the visit-to-visit heart rate variability expressed as the coefficient of variation in heart rate (HR-CV). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using the HR-CV < 0.08 subgroup as a reference.

RESULTS

The adjusted OR of paroxysmal AF was 1.866 (95% CI = 1.205-2.889) for the HR-CV ≥ 0.08 and <0.10 subgroup, 1.889 (95% CI = 1.174-3.038) for the HR-CV ≥ 0.10 and <0.12 subgroup, and 5.564 (95% CI = 3.847-8.047) for the HR-CV ≥ 0.12 subgroup. The adjusted OR of persistent AF was 2.425 (95% CI = 1.921-3.062) for the HR-CV ≥ 0.08 and <0.10 subgroup, 4.312 (95% CI = 3.415-5.446) for the HR-CV ≥ 0.10 and <0.12 subgroup, and 5.651 (95% CI = 4.586-6.964) for the HR-CV ≥ 0.12 subgroup.

CONCLUSIONS

HR-CV can facilitate the identification of patients with AIS at a high risk of paroxysmal AF.

A cross-sectional study to validate an administrative back pain severity classification tool based on the graded chronic pain scale

Treatment of chronic lower back pain (CLBP) should be stratified for best medical and economic outcome. To improve the targeting of potential participants for exclusive therapy offers from payers, Freytag et al. developed a tool to classify back pain chronicity classes (CC) based on claim data. The aim of this study was to evaluate the criterion validity of the model. Administrative claim data and self-reported patient information from 3,506 participants (2014-2021) in a private health insurance health management programme in Germany were used to validate the tool. Sensitivity, specificity, and Matthews' correlation coefficient (MCC) were calculated comparing the prediction with actual grades based on von Korff's graded chronic pain scale (GCPS). The secondary outcome was an updated view on direct health care costs (€) of patients with back pain (BP) grouped by GCPS. Results showed a fair correlation between predicted CC and actual GCPS grades. A total of 69.7% of all cases were correctly classified. Sensitivity and specificity rates of 54.6 and 76.4% underlined precision. Correlation between CC and GCPS with an MCC of 0.304 also indicated a fair relationship between prediction and observation. Cost data could be clearly grouped by GCPS: the higher the grade, the higher the costs and the use of health care. This was the first study to compare the predicted severity of BP using claim data with the actual severity of BP by GCPS. Based on the results, the usage of CC as a single tool to determine who receives CLBP treatment cannot be recommended. CC is a good tool to segment candidates for specific types of intervention in BP. However, it cannot replace a medical screening at the beginning of an intervention, as the rate of false negatives is too high. Trial registration The study was conducted using routinely collected data from an intervention, which was previously evaluated and registered retrospectively in the German Registry of Clinical Trials under DRKS00015463 (04/09/2018). Informed consent and the self-reported questionnaire have remained unchanged since the study and, therefore, are still valid according to the ethics proposal.

Association of Statin Therapy With Major Adverse Cardiovascular and Limb Outcomes in Patients With End-stage Kidney Disease and Peripheral Artery Disease Receiving Maintenance Dialysis

IMPORTANCE

Controversy exists regarding whether statin therapy has benefits for patients with kidney failure, and the consequences of statin therapy for patients with kidney failure and concomitant peripheral artery disease (PAD) are particularly uncertain.

OBJECTIVE

To evaluate the association of statin therapy with cardiovascular (CV) and limb outcomes among patients with kidney failure and concomitant PAD and dyslipidemia who are receiving long-term maintenance dialysis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study used data from the Taiwan National Health Insurance Research Database. A total of 20 731 patients with kidney failure receiving long-term maintenance dialysis who were diagnosed with PAD and dyslipidemia between January 1, 2001, and December 31, 2013, were identified, and 10 767 patients met study criteria. Data were analyzed from June 8, 2021, to June 2, 2022.

MAIN OUTCOMES AND MEASURES

Primary outcomes were all-cause death and the composite of endovascular therapy (EVT) and amputation. Other outcomes of interest included CV events (CV death, acute myocardial infarction, ischemic stroke, and hospitalization for heart failure), major adverse limb events (new-onset claudication, new-onset critical limb ischemia, EVT, and nontraumatic amputation), and all-cause readmission. All outcomes were examined at 1 year and 3 years of follow-up. To minimize selection bias, propensity score matching on a 1:1 ratio was performed among patients receiving statin therapy (statin group) and patients not receiving statin therapy (nonstatin group). A defined daily dose (DDD) approach was used to evaluate whether the association of statin therapy with the risk of primary outcomes was dose dependent.

RESULTS

Among 20 731 patients with kidney failure and concomitant PAD and dyslipidemia receiving long-term maintenance dialysis, 10 767 patients (5593 women [51.9%]; mean [SD] age, 68.5 [11.5] years; all of Taiwanese ethnicity) met the predetermined study criteria; of those, 3597 patients were receiving statin therapy, and 7170 were not. A total of 6470 patients (mean [SD] age, 66.4 [11.3] years; 3359 women [51.9%]) were included in the 1:1 propensity score-matched cohort, with 3235 patients in each group (statin and nonstatin). The incidence and risk of CV and all-cause death were significantly lower in the statin group vs the nonstatin group at 3 years of follow-up (CV death: 611 patients [18.9%] vs 685 patients [21.2%]; hazard ratio [HR], 0.86 [95% CI, 0.77-0.96]; P = .008; all-cause death: 1078 patients [33.3%] vs 1138 patients [35.2%]; HR, 0.92 [95% CI, 0.84-0.996]; P = .04). Statin use was also associated with a significantly lower incidence and risk of the composite adverse limb outcome of EVT and amputation at 3 years of follow-up (314 patients [9.7%] vs 361 patients [11.2%]; subdistribution HR, 0.85 [95% CI, 0.73-0.99]; P = .04). Results of subgroup analyses were consistent with those of the primary analysis across all subgroup variables. In the adjusted dose-response analysis, the risk reduction associated with statin use increased in a dose-dependent manner for both all-cause death (HR: 0.95 for DDD <0.50, 0.92 for DDD 0.50-0.99, 0.85 for DDD 1.00-1.49, and 0.79 for DDD ≥1.50; P = .002 for trend) and the composite outcome of EVT and amputation (subdistribution HR: 0.79 for DDD <0.50, 0.78 for DDD 0.50-0.99, 0.82 for DDD 1.00-1.49, and 0.58 for DDD ≥1.50; P = .002 for trend) compared with no statin therapy; however, not all findings in the DDD analysis were statistically significant.

CONCLUSIONS AND RELEVANCE

In this cohort study, statin therapy was associated with reductions in the risk of all-cause death, CV death, and the composite adverse limb outcome of EVT and amputation. These findings suggest that statin therapy may have protective CV and limb benefits for patients with kidney failure and concomitant PAD who are receiving long-term maintenance dialysis.

Effectiveness and Safety of Clopidogrel vs Aspirin in Elderly Patients With Ischemic Stroke

OBJECTIVE

To evaluate the risks of recurrent stroke and major bleeding events with clopidogrel and aspirin use among patients aged 80 years or older.

PATIENTS AND METHODS

This retrospective cohort study was conducted using the Full Population Data of the Health and Welfare Database in Taiwan. Patients aged 80 years or older who received monotherapy with clopidogrel or aspirin following hospitalization for primary acute ischemic stroke between January 1, 2009, and December 31, 2018, were included. Inverse probability of treatment weighting was used to balance measured covariates between clopidogrel and aspirin users. Measured outcomes included recurrent acute ischemic stroke, acute myocardial infarction, composite cardiovascular events (recurrent stroke or acute myocardial infarction), intracranial hemorrhage, major gastrointestinal tract bleeding, and composite major bleeding events (intracranial hemorrhage or major gastrointestinal tract bleeding).

RESULTS

A total of 15,045 patients were included in the study, 1979 of whom used clopidogrel and 13,066 who used aspirin following hospitalization for primary acute ischemic stroke. Clopidogrel use was associated with significantly lower risk of recurrent acute ischemic stroke (hazard ratio [HR], 0.89; 95% CI, 0.83 to 0.96; P=.002), composite cardiovascular events (HR, 0.88; 95% CI, 0.82 to 0.95; P<.001), intracranial hemorrhage (HR, 0.71; 95% CI, 0.56 to 0.90; P=.005), and composite major bleeding events (HR, 0.89; 95% CI, 0.80 to 0.99; P=.04) compared with aspirin use.

CONCLUSION

In patients aged 80 years or older with primary acute ischemic stroke, clopidogrel users had lower risks of recurrent stroke and the composite cardiovascular events compared with aspirin users. Clopidogrel users also had lower risks of intracranial hemorrhage and the composite major bleeding events compared with aspirin users.

Oral anticoagulant decreases stroke recurrence in patients with atrial fibrillation detected after stroke

Background

Atrial fibrillation detected after stroke (AFDAS) has a lower risk of ischemic stroke recurrence than known atrial fibrillation (KAF). While the benefit of oral anticoagulants (OAC) for preventing ischemic stroke recurrence in KAF is well established, their role in patients with AFDAS is more controversial. This study aimed to evaluate the association between OAC use and the risk of recurrent ischemic stroke in patients with AFDAS in a real-world setting.

Methods

This nationwide retrospective cohort study was conducted using the Taiwan National Health Insurance Research Database. Patients hospitalized with a first-ever ischemic stroke and AFDAS confirmed within 30 days after hospitalization were assigned to OAC and non-OAC cohorts. Inverse probability of treatment weighting was applied to balance the baseline characteristics of the cohorts. The primary outcome was ischemic stroke recurrence. Secondary outcomes were intracranial hemorrhage (ICH), death, and the composite outcome of "ischemic stroke recurrence, ICH, or death." Multivariate Cox proportional hazard models were used to estimate adjusted hazard ratios (aHR) and 95% confidence intervals (CI).

Results

A total of 4,508 hospitalized patients with stroke and AFDAS were identified. Based on OAC use, 2,856 and 1,652 patients were assigned to the OAC and non-OAC groups, respectively. During the follow-up period (median duration, 2.76 years), the OAC cohort exhibited a lower risk of ischemic stroke recurrence (aHR, 0.84; 95% CI, 0.70-0.99), death (aHR, 0.65; 95% CI, 0.58-0.73), and composite outcome (aHR, 0.70; 95% CI, 0.63-0.78) than did the non-OAC cohort. The risk of ICH (aHR, 0.96; 95% CI, 0.62-1.50) was not significantly different between the two cohorts.

Conclusion

OAC use in patients with AFDAS was associated with reduced risk of ischemic stroke recurrence, without an increased risk of ICH. This supports current guidelines recommending OACs for secondary stroke prevention in patients with AF, regardless of the time of diagnosis.

Development and Validation of a Novel Score for Predicting Paroxysmal Atrial Fibrillation in Acute Ischemic Stroke

Atrial fibrillation (AF)-whether paroxysmal or sustained-increases the risk of stroke. We developed and validated a risk score for identifying patients at risk of paroxysmal atrial fibrillation (pAF) after acute ischemic stroke (AIS). A total of 6033 patients with AIS who received 24 h Holter monitoring were identified in the Chang Gung Research Database. Among the identified patients, 5290 with pAF and without AF were included in the multivariable logistic regression analysis to develop the pAF prediction model. The ABCD-SD score (Age, Systolic Blood pressure, Coronary artery disease, Dyslipidemia, and Standard Deviation of heart rate) comprises age (+2 points for every 10 years), systolic blood pressure (-1 point for every 20 mmHg), coronary artery disease (+2 points), dyslipidemia (-2 points), and standard deviation of heart rate (+2 points for every 3 beats per minute). Overall, 5.2% (274/5290) of patients had pAF. The pAF risk ranged from 0.8% (ABCD-SD score ≤ 7) to 18.3% (ABCD-SD score ≥ 15). The model achieved an area under the receiver operating characteristic curve (AUROCC) of 0.767 in the model development group. The ABCD-SD score could aid clinicians in identifying patients with AIS at risk of pAF for advanced cardiac monitoring.

Sex differences following percutaneous coronary intervention or coronary artery bypass surgery for acute myocardial infarction

Background

Women have been underrepresented in the literature; the effects of female sex on outcomes in patients with acute myocardial infarction (AMI) remain unclear.

Objectives

This study compares the real-world outcomes of women and men with AMI who have undergone revascularization via percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery (CABG).

Methods

This is a retrospective cohort study utilizing data from the Taiwan National Health Insurance database. We identified patients who were admitted for AMI and who underwent coronary revascularization during the index admission period between January 1, 2001, and December 31, 2013. Patients were then categorized based on the treatment received into PCI and CABG groups. In-hospital and long-term outcomes were compared between women and men in each group. Interaction tests were then performed to determine whether the differences between sexes were modified by the mode of revascularization. Analyses were repeated after propensity score matching between women and men in each group to minimize possible confounders. We also conducted subgroup analyses, stratifying by the presence of diabetes mellitus, congestive heart failure, and chronic kidney disease.

Results

We enrolled 67,534 patients who met the inclusion criteria in the analysis; 60,207 patients had undergone PCI (13,514 female and 46,693 male), while 7327 patients had received CABG (1762 female and 5565 male). Prior to matching, enrolled female patients were older on average, with more comorbidities. In-hospital and long-term outcomes were worse in women, particularly in the PCI group. After matching, the incidence of hospitalization for heart failure (HHF) was higher in women (10.4% vs 8.0%, OR 1.32, 95% CI 1.22–1.43), with fewer repeat revascularizations (28.1% vs 32.4%, OR 0.84, 95% CI 0.81–0.88). Both observations were more pronounced in the PCI group (HHF: P for interaction = 0.0496; repeat revascularization: P for interaction = 0.021).

Conclusions

Women presenting with AMI exhibited worse in-hospital and long-term outcomes than men, especially among women who received PCI as the initial mode of revascularization. Women who underwent PCI were more likely to be admitted for heart failure during follow-up. Possible socioeconomic inequalities or a distinct pathobiology of cardiac ischemia between sexes may underlie these results; thus, further investigation is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13293-022-00427-1.

Among patients with acute myocardial infarction (AMI), women were older, had more comorbid conditions, and were less likely to be discharged with optimal medical therapy than their male counterparts.

In-hospital and long-term outcomes were worse among women compared to men, particularly in those who received percutaneous coronary intervention (PCI) as the mode of revascularization for AMI. Despite worse in-hospital survival, women were less likely to receive mechanical cardiac support.

After propensity score matching between women and men for baseline characteristics, the incidence of hospitalization for heart failure was higher among women during long-term follow-up, especially among patients who had undergone PCI. Contrarily, the incidence of repeat revascularization procedures was lower in women in the long term.

Mechanisms underlying cardiac ischemia likely differ between women and men, and socioeconomic inequalities that influence treatment of female patients are also possible.

Guideline adherence in speech and language therapy in stroke aftercare. A health insurance claims data analysis

Background

Impairments to comprehension and production of speech (aphasia, dysarthria) and swallowing disorders (dysphagia) are common sequelae of stroke, reducing patients’ quality of life and social participation. Treatment oriented on evidence-based guidelines seems likely to improve outcomes. Currently, little is known about guideline adherence in stroke aftercare for the above-mentioned sequelae. This study aims to analyse guideline adherence in the treatment of aphasia, dysarthria and dysphagia after stroke, based on suitable test parameters, and to determine factors that influence the implementation of recommended therapies.

Methods

Six test parameters were defined, based on systematic study of guidelines for the treatment of speech impairments and swallowing disorders (e.g. comprehensive diagnostics, early initiation and continuity). Guideline adherence in treatment was tested using claims data from four statutory health insurance companies. Multivariate logistic and linear regression analyses were performed in order to test the outcomes.

Results

4,486 stroke patients who were diagnosed with specific disorders or received speech therapy were included in the study. The median age was 78 years; the proportion of women was 55.9%. Within the first year after the stroke, 90.3% of patients were diagnosed with speech impairments and swallowing disorders. Overall, 44.1% of patients received outpatient speech and language therapy aftercare. Women were less frequently diagnosed with specific disorders (OR 0.70 [95%CI:0.55/0.88], p = 0.003) and less frequently received longer therapy sessions (OR 0.64 [95%CI:0.43/0.94], p = 0.022). Older age and longer hospitalization duration increased the likelihood of guideline recommendations being implemented and of earlier initiation of stroke aftercare measures.

Conclusions

Our observations indicate deficits in the implementation of guideline recommendations in stroke aftercare. At the same time, they underscore the need for regular monitoring of implementation measures in stroke aftercare to address group-based disparities in care.

Potentially preventable hospital readmissions after patients' first stroke in Taiwan

Readmission is an important indicator of the quality of care. The purpose of this study was to explore the probabilities and predictors of 30-day and 1-year potentially preventable hospital readmission (PPR) after a patient's first stroke. We used claims data from the National Health Insurance (NHI) from 2010 to 2018. Multinomial logistic regression was used to assess the predictors of 30-day and 1-year PPR. A total of 41,921 discharged stroke patients was identified. We found that hospital readmission rates were 15.48% within 30-days and 47.25% within 1-year. The PPR and non-PPR were 9.84% (4123) and 5.65% (2367) within 30-days, and 30.65% (12,849) and 16.60% (6959) within 1-year, respectively. The factors of older patients, type of stroke, shorter length of stay, higher Charlson Comorbidity Index (CCI), higher stroke severity index (SSI), regional hospital, public and private hospital, and hospital in the lower urbanized area were associated significantly with the 30-day PPR. In addition, the factors of male, hospitalization year, and monthly income were associated significantly with 1-year PPR. The ORs of long-term PPR showed a decreasing trend since implementing the national health insurance post-acute care (PAC) program in 2014 and a dramatic drop in 2018 after the government expanded the long-term care plan-LTC 2.0 in 2017. The results showed that better discharge planning, implementing post-acute care programs and long-term care plan-LTC 2.0 may benefit the care of stroke patients and help reduce long-term readmission in Taiwan.

Utilization of screening and treatment for osteoporosis among stroke survivors

BACKGROUND

Stroke survivors are prone to osteoporosis and fractures. However, bone mineral density (BMD) testing and osteoporosis treatment were underutilized in patients with recent stroke. We aimed to examine whether stroke has an impact on the utilization of BMD testing and osteoporosis treatment as well as the determinants of their utilization in stroke patients using nationwide population-based data in Taiwan.

METHODS

We identified patients aged 55 years and older who were hospitalized for hemorrhagic or ischemic stroke as the stroke cohort, and age- and sex-matched patients hospitalized for reasons other than stroke, fracture, or fall as the non-stroke cohort. We used the Fine-Gray sub-distribution hazard competing risk regression model to determine the predictors for BMD testing and osteoporosis treatment.

RESULTS

A total of 32997 stroke patients and 32997 age- and sex-matched controls comprised the stroke and non-stroke cohorts, respectively. BMD testing and osteoporosis treatment were performed in 1.0% and 5.2% of the stroke patients, respectively, within one year after hospitalization while these measures were performed in 0.8% and 4.7% of the controls. Stroke patients were more likely to receive BMD testing (adjusted hazard ratio [HR] 1.33; 95% confidence interval [CI] 1.11-1.58) and osteoporosis treatment (adjusted HR 1.19; 95% CI 1.11-1.29). Female sex, osteoporosis, prior BMD testing, and low-trauma fractures after stroke increased the likelihood of using BMD testing and osteoporosis treatment whereas greater stroke severity reduced the likelihood of receiving both measures.

CONCLUSIONS

Both BMD testing and osteoporosis treatment were underutilized among stroke survivors even though they had a higher chance of receiving both measures than non-stroke patients.

Initial in-hospital heart rate is associated with long-term survival in patients with acute ischemic stroke

Aims

Increased heart rate has been associated with stroke risk and outcomes. The purpose of this study was to explore the long-term prognostic value of initial in-hospital heart rate in patients with acute ischemic stroke (AIS).

Methods

We analyzed data from 21,655 patients with AIS enrolled (January 2010–September 2018) in the Chang Gung Research Database. Mean initial in-hospital heart rates were averaged and categorized into 10-beat-per-minute (bpm) increments. The primary and secondary outcomes were all-cause mortality and cardiovascular death. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable adjusted Cox proportional hazard models, using the heart rate < 60 bpm subgroup as the reference.

Results

The adjusted HRs for all-cause mortality were 1.23 (95% CI 1.08–1.41) for heart rate 60–69 bpm, 1.74 (95% CI 1.53–1.97) for heart rate 70–79 bpm, 2.16 (95% CI 1.89–2.46) for heart rate 80–89 bpm, and 2.83 (95% CI 2.46–3.25) for heart rate ≥ 90 bpm compared with the reference group. Likewise, heart rate ≥ 60 bpm was also associated with an increased risk of cardiovascular death (adjusted HR 1.18 [95% CI 0.95–1.46] for heart rate 60–69 bpm, 1.57 [95% CI 1.28–1.93] for heart rate 70–79 bpm, 1.98 [95% CI 1.60–2.45] for heart rate 80–89 bpm, and 2.36 [95% CI 1.89–2.95] for heart rate ≥ 90 bpm).

Conclusions

High initial in-hospital heart rate is an independent predictor of all-cause mortality and cardiovascular death in patients with AIS.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-021-01953-5.

Oral Anticoagulation Timing in Patients with Acute Ischaemic Stroke and Atrial Fibrillation

BACKGROUND AND PURPOSE

Oral anticoagulants (OACs) prevent stroke recurrence and vascular embolism in patients with acute ischaemic stroke (AIS) and atrial fibrillation (AF). Current guidance recommends a "1-3-6-12 day"' rule to resume OACs after AIS, based mainly on empirical consensus. This study investigated the suitability of guideline-recommended timing for OAC initiation.

METHODS

To overcome immortal time bias, we emulated a sequence of randomized placebo-controlled trials and constructed 90 propensity score-matched cohorts of 12,307 patients with AF and AIS from 2012 to 2016. We compared the risk of composite effectiveness and safety outcome in the early vs no OAC use group and in the delayed vs no OAC use. Indirect comparison between early and delayed use was conducted using a network meta-analysis.

RESULTS

Across the groups of AIS severity, the risks of composite outcome or effectiveness outcome were lower in the OAC use group than the no use group and the risks were similar between the early and delayed use groups. In patients with severe AIS, those receiving early OACs use had an increased risk of safety outcome, with HR of 2.10 (CI: 1.13-3.92) compared with those without OAC use, and HR of 1·44 (CI: 0·99-2·09) compared with those receiving delayed use.

CONCLUSIONS

In AF patients with severe AIS, early OAC use before the guideline-recommended days appeared to increase the risk of bleeding events, although the OAC initiation time seemed not to affect the risk of serious vascular events. The optimal severity-specific timing for OAC initiation after AIS requires further evaluation.

Colchicine Use and Risks of Stroke Recurrence in Acute Non-Cardiogenic Ischemic Stroke Patients: A Population-Based Cohort Study

Background: The objective is to study whether the cardiovascular protective effects of colchicines could be applied to non-cardiogenic ischemic stroke (IS) patients. Patients and Methods: Non-cardiogenic IS patients were identified from the National Health Insurance Research Database. Eligible patients were divided into chronic and non-chronic use categories based on their long-term status of colchicine use. The non-chronic use category was subdivided into (1) non-user and (2) new user groups while the chronic use category was divided into (3) former user and (4) long-term user groups according to the patient's recent status of colchicine use. Inverse probability of treatment weights for propensity scores was used to balance the baseline characteristics. The primary outcome was recurrent IS, which was compared within the non-chronic use and chronic use categories. Results: In the non-chronic use category, the number of patients was 355,498 and 912 in the non-user and new user groups, respectively. In the chronic use category, the number of patients was 4737 and 4354 in the former user and long-term user groups, respectively. In the non-chronic use category, patients in the new user group had a marginally lower risk of recurrent IS at 6-months (subdistribution hazard ratio [SHR], 0.95; 95% confidence interval [CI], 0.94-0.97) and 2-years (SHR, 0.92; 95% CI, 0.91-0.93) follow up. In the chronic use category, patients in the long-term user group also had a marginally lower risk of recurrent IS at 6-months (SHR, 0.87; 95% CI, 0.86-0.88) and 2-years (SHR, 0.87; 95% CI, 0.86-0.88) follow up. The effect of colchicine on the reduced risk of recurrent IS was more favorable in patients who also used statins. Conclusions: Recent colchicine use in acute non-cardiogenic IS patients is associated with marginal fewer incidences of recurrent IS. Patients with concurrent statin use may have more profound protective effects.

Major adverse cardiovascular and limb events in patients with diabetes treated with GLP-1 receptor agonists vs DPP-4 inhibitors

AIMS/HYPOTHESIS

The safety and efficacy of glucagon-like peptide-1 receptor agonists (GLP1RAs) and dipeptidyl peptidase-4 inhibitors (DPP4is) in major cardiovascular adverse events were previously examined in cardiovascular outcome trials. However, the effects of these drugs on adverse limb outcomes were poorly examined. This study aimed to determine the real-world outcomes of patients with diabetes mellitus receiving GLP1RAs as compared with those receiving DPP4is in terms of major adverse cardiovascular and limb events.

METHODS

A retrospective cohort study was conducted with data collected by the Taiwan National Health Insurance database between 1 May 2011 and 31 December 2017. Patients who were treated for type 2 diabetes with a GLP1RA or DDP4i during this period (n = 1,080,993), were identified. The primary outcome was a composite of major adverse limb events, defined as peripheral artery disease (PAD), critical limb ischaemia, percutaneous transluminal angioplasty or peripheral bypass for PAD, and amputation. The secondary cardiovascular outcome was the composite of cardiovascular death, non-fatal myocardial infarction and non-fatal ischaemic stroke. Propensity-score matching (PSM) at a 1:3 ratio between GLP1RA and DPP4i groups was done to minimise possible selection bias.

RESULTS

A total of 948,342 individuals treated between 1 May 2011 and 31 December 2017, were identified, with 4460 in the GLP1RA group and 13,380 in the DPP4i group after PSM. The incidence of primary composite outcome events was significantly lower in those treated with GLP1RAs compared with those treated with DPP4is (2.59 vs 4.22 events per 1000 person-years; subdistribution HR [SHR] 0.63 [95% CI 0.41, 0.96]), primarily due to lower rates of amputation (1.29 events per 1000 person-years for GLP1RAs vs 2.4 events per 1000 person-years for DPP4is; SHR 0.55 [95% CI 0.30, 0.99]). Treatment with GLP1RAs was also associated with significantly lower risks of secondary composite outcome events (11.02 vs 17.95 events per 1000 person-years; HR 0.62 [95% CI 0.51, 0.76]). Moreover, the observed beneficial effects of GLP1RAs on reducing composite adverse limb outcomes were particularly noticeable in the non-cardiovascular patients and statin users (p for interaction <0.05).

CONCLUSIONS/INTERPRETATION

In individuals with diabetes, the use of GLP1RAs was associated with significantly lower risks of major adverse limb events when compared with the use of DPP4is. The reduction in risk was driven largely by reduced rate of amputations. Moreover, treatment with GLP1RAs was also associated with lower risks of cardiovascular death, non-fatal stroke, non-fatal myocardial infarction and death from any cause. However, some unexplored confounding factors may exist in this observation study and future large-scale randomised controlled trials are needed.

Functional and Cognitive Impairments Increased Risks of Outcomes of Healthcare Utilization in Patients With Stroke Receiving Home and Community-Based Care in Taiwan

Aim: Stroke is a leading cause of disability; however, little is known about the outcomes of the utilization of long-term care (LTC) recipients in Taiwan. This study aimed to quantify the burdens of disease of stroke survivors receiving LTC by evaluating the outcomes of their utilization including mortality, readmissions, and re-emergency within 1 year after diagnoses of strokes. Methods: By interlinkages among the national mortality registry, LTC dataset (LTC-CM), and the National Health Insurance Research Dataset (NHIRD), the outcomes and the factors associated with receiving LTC up to 1 year were explored. Patients were aged 50 years and over with an inpatient claim of the first diagnosis of stroke of intracerebral hemorrhage (ICH) and ischemic stroke during 2011-2016. Outcomes of the healthcare utilization include rehospitalization and re-emergency. Results: There were 15,662 patients with stroke who utilized the LTC services in the dataset among the stroke population in NHIRD. Stroke survivors receiving LTC showed no difference in clinical characteristics and their expected years of life loss (EYLL = 7.4 years) among those encountered in NHIRD. The LTC recipients showed high possibilities to be rehospitalized and resent to emergency service within 1 year after diagnosis. Apart from the comorbidity and stroke severity, both the physical and mental functional disabilities and caregiving resources predicted the outcomes of the utilization. Conclusions: For stroke survivors, both severe functional impairments and cognitive impairments were found as important factors for healthcare utilizations. These results regarding reserving functional abilities deserve our consideration in making the decision on the ongoing LTC policy reform in the aged society of Taiwan.

Effects of long-term anti-seizure medication monotherapy on all-cause death in patients with post-stroke epilepsy: a nationwide population-based study in Taiwan

OBJECTIVE

We aim to compare the effect of long-term anti-seizure medication (ASM) monotherapy on the risk of death and new ischemic stroke in patients with post-stroke epilepsy (PSE).

PATIENTS AND METHODS

We identified all hospitalized patients (≥ 20 years) with a primary diagnosis of ischemic or hemorrhagic stroke from 2001 to 2012 using the National Health Insurance Research Database in Taiwan. The PSE cohort were defined as the stroke patients (1) who had no epilepsy and no ASMs use before the index stroke, and (2) who had epilepsy and ASMs use after 14 days from the stroke onset. The patients with PSE receiving ASM monotherapy were enrolled and were categorized into phenytoin, valproic acid, carbamazepine, and new ASM groups. We employed the Cox regression model to estimate the unadjusted and adjusted hazard ratios (HRs) with 95 % confidence intervals (CIs) of death and new ischemic stroke within 5 years across all groups, using the new ASM group as the reference.

RESULTS

Of 6962 patients with PSE using ASM monotherapy, 3917 (56 %) were on phenytoin, 1623 (23 %) on valproic acid, 457 (7 %) on carbamazepine, and 965 (14 %) on new ASMs. After adjusting for confounders, compared with new ASM users, phenytoin users had a higher risk of death in 5 years (HR: 1.64; 95 % CI: 1.06-2.55). On the other hand, all ASM groups showed a similar risk of new ischemic stroke in 5 years.

CONCLUSIONS

Among patients with PSE on first-line monotherapy, compared to new ASMs, use of phenytoin was associated with a higher risk of death in 5 years.

Associations between stroke type, stroke severity, and pre-stroke osteoporosis with the risk of post-stroke fracture: A nationwide population-based study

Background Recognizing the post-stroke fracture risk factors is crucial for targeted intervention and primary fracture prevention. We aimed to investigate whether stroke types, stroke severity, and pre-stroke osteoporosis are associated with post-stroke fracture. Methods In a nationwide cohort, we identified previously fracture-free patients who suffered from first-ever stroke, either acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH), between 2003 and 2015. Information regarding stroke severity, osteoporosis, comorbidity, and medication information was collected. The outcomes analyzed included hip fracture, spine fracture, and other fractures. Cumulative incidence functions (CIFs) were used to estimate the cumulative incidence of fractures over time after accounting for competing risk of death. Multivariable Fine and Gray models were used to determine the adjusted hazard ratio (HR) and 95% confidence interval (CI). Results Of the 41,895 patients with stroke, the 5-year CIFs of any incident fracture, hip fracture, spine fracture, and other fractures were 8.03%, 3.42%, 1.87%, and 3.05%, respectively. The fracture risk did not differ between patients with AIS and ICH. While osteoporosis increased the risk of post-stroke fracture (adjusted HR [95% CI],1.42 [1.22-1.66]), stroke severity was inversely associated with post-stroke fracture (moderate, 0.88 [0.81-0.96] and severe, 0.39 [0.34-0.44], compared with mild stroke severity). Conclusions Stroke survivors had an over 8% fracture risk at 5 years after stroke. Mild stroke severity and osteoporosis were significantly associated with post-stroke fracture risk, whereas stroke type was not. Our results call for effective measures for bone health screening and fracture prevention in patients with stroke.

Creation and Validation of a Stroke Scale to Increase Utility of National Inpatient Sample Administrative Data for Clinical Stroke Research

INTRODUCTION

The National Inpatient Sample (NIS) has led to several breakthroughs via large sample size. However, utility of NIS is limited by the lack of admission NIHSS and 90-day modified Rankin score (mRS). This study creates estimates for stroke severity at admission and 90-day mRS using NIS data for acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT).

METHODS

Three patient cohorts undergoing MT for AIS were utilized: Cohort 1 (N = 3729) and Cohort 3 (N = 1642) were derived from NIS data. Cohort 2 (N=293) was derived from a prospectively-maintained clinical registry. Using Cohort 1, Administrative Stroke Outcome Variable (ASOV) was created using disposition and mortality. Factors reflective of stroke severity were entered into a stepwise logistic regression predicting poor ASOV. Odds ratios were used to create the Administrative Data Stroke Scale (ADSS). Performances of ADSS and ASOV were tested using Cohort 2 and compared with admission NIHSS and 90-day mRS, respectively. ADSS performance was compared with All Patient Refined-Diagnosis Related Group (APR-DRG) severity score using Cohort 3.

RESULTS

Agreement of ASOV with 90-day mRS > 2 was fair (κ = 0.473). Agreement with 90-day mRS > 3 was substantial (κ = 0.687). ADSS significantly correlated (p < 0.001) with clinically-significant admission NIHSS > 15. ADSS performed comparably (AUC = 0.749) to admission NIHSS (AUC = 0.697) in predicting 90-day mRS > 2 and mRS > 3 (AUC = 0.767, 0.685, respectively). ADSS outperformed APR-DRG severity score in predicting poor ASOV (AUC = 0.698, 0.682, respectively).

CONCLUSION

We developed and validated measures of stroke severity at admission (ADSS) and outcome (ASOV, estimate for 90-day mRS > 3) to increase utility of NIS data in stroke research.

Reduced Mortality Associated With the Use of Metformin Among Patients With Autoimmune Diseases

OBJECTIVE

Metformin has been linked to anti-proliferative and anti-inflammatory mechanisms. In this study, we aimed to examine the long-term impact of metformin on mortality and organ damage in patients with autoimmune diseases and type 2 diabetes mellitus (T2DM).

METHODS

We conducted a cohort study using the National Health Insurance Research Database in Taiwan between 1997 and 2013. Based on metformin and other anti-diabetic agent prescriptions, we categorized all patients with autoimmune diseases into either the metformin group (metformin administration for at least 28 days) or the non-metformin group. The primary outcomes were all-cause mortality and annual admission rate, while the secondary outcome was target organ damage. We followed patients from the index date to the date on which the event of interest occurred, death, or the end of this study.

RESULTS

Our cohort study included 3,359 subjects for analysis. During a mean follow up of 5.2 ± 3.8 years, the event rate of all-cause mortality was 228 (33.6%) in the metformin group and 125 (36.9%) in the non-metformin group. The risk of both all-cause mortality and annual number of admissions for autoimmune diseases was significantly lower in the metformin group than in the non-metformin group [hazard ratio (HR) 0.77; 95% CI 0.62-0.96 and risk ratio (RR) 0.81; 95% CI 0.73-0.90, respectively].

CONCLUSION

Metformin may add benefits beyond T2DM control with regard to reducing all-cause mortality and admission rate, as well as minimizing end-organ injury in lungs and kidneys among patients with autoimmune diseases.

Comparison of hospital length of stay of acute ischemic stroke patients with non-valvular atrial fibrillation started on rivaroxaban or warfarin treatment during hospitalization

OBJECTIVE

To compare the hospital length of stay (LOS) between rivaroxaban and warfarin in hospitalized acute stroke patients with non-valvular atrial fibrillation (NVAF) in Japan.

METHODS

This was a retrospective, observational study using a Japanese hospital claims database. Data of NVAF patients who were started on oral anticoagulant (OAC) treatment during hospitalization were extracted and LOS-OAC (period from the initiation of index OAC therapy to the end of hospitalization or censoring date) and medical costs were compared between rivaroxaban and warfarin treatments. To compare LOS-OAC, a time-to-event analysis was performed using the Kaplan-Meier method. The analysis period was from April 2012 to December 2015.

RESULTS

This study included 773 rivaroxaban users and 1077 warfarin users. After the propensity score matching, 546 patients for each treatment constituted the matched cohorts. Although the rivaroxaban users had a similar LOS-OAC to warfarin users (median, 18 vs. 19 days, p = .657) in the matched cohorts, 3 days shorter LOS-OAC was observed in the rivaroxaban users (median, 17 vs. 20 days, p = .043) after IPTW adjustment. Subgroup analysis by the severity of stroke after IPTW adjustment demonstrated that rivaroxaban users had a shorter LOS-OAC than warfarin users among patients with mild (median, 10 vs. 14 days) and moderate stroke severity (22 vs. 27 days), but not among those with severe stroke severity (26 vs. 25 days).

LIMITATIONS

It is not possible to say that the only confounder was stroke severity and therefore other possible known and unknown confounders could not be ruled out.

CONCLUSIONS

The rivaroxaban users had a 3-day shorter LOS-OAC after IPTW-adjustment. Using rivaroxaban was associated with 4-5 days shorter LOS-OAC than using warfarin in patients with mild or moderate stroke, though treatment selection did not have a large impact in patients with severe stroke.

Comparison of long-term efficacy and safety between cilostazol and clopidogrel in chronic ischemic stroke: a nationwide cohort study

Background:

Previous clinical trials showed a significant difference in efficacy and safety among antiplatelets in acute ischemic stroke (IS). The present study wished to compare the efficacy and safety head-to-head between cilostazol and clopidogrel in chronic IS.

Methods:

This open prospective cohort study recruited chronic IS patients with an index hospitalization between 2001 and 2013 from Taiwan National Health Insurance Research Database. In the 504,191 hospitalized patients, patients who had missing information and history of atrial fibrillation or rheumatic heart disease, received mechanical valve replacement or anticoagulants, expired during the index hospitalization, received follow-up ⩽6 months, or had recurrent stroke within 6 months after index stroke were excluded.

Results:

Among the 15,968 eligible patients, 502 patients who consistently received either cilostazol or clopidogrel from the 7th month after the index stroke were included for analysis after propensity score matching. The 3-year primary outcomes showed similar frequency of recurrent IS, all-cause mortality, and acute myocardial infarction (AMI), and similar frequency of intracerebral hemorrhage, gastrointestinal bleeding, and major bleeding between the cilostazol and clopidogrel groups. Subgroup analysis revealed that patients with a history of hypertension or gastrointestinal bleeding had a trend of having lower frequency of recurrent IS or major bleeding, respectively, in the cilostazol group.

Conclusion:

The present real-world study demonstrated no significant difference in efficacy and safety between cilostazol and clopidogrel in chronic IS. However, cilostazol might be better than clopidogrel in patients with a history of hypertension or gastrointestinal bleeding.

Holiday Season and Weekend Effects on Stroke Mortality: A Nationwide Cohort Study Controlling for Stroke Severity

Background The effect of holiday season admission for stroke on mortality has not been investigated. Thus, we aimed to evaluate whether "holiday season" and "weekend" effects exist on mortality risk for stroke admission. Methods and Results A nationwide cohort study was conducted using Taiwan's National Health Insurance Research Database. We identified all patients admitted for stroke between 2011 and 2015 in Taiwan, and categorized them according to the admission date: holiday season (at least 4 days off) (n=3908), weekend (n=13 774), and weekday (n=49 045). We analyzed in-hospital, 7-day, and 30-day mortality using multivariable logistic regression, adjusting for stroke severity and other confounders. Compared with weekday admissions, holiday season admission for stroke was significantly associated with a 20%, 33%, and 21% increase in in-hospital, 7-day, and 30-day mortality, respectively. Compared with weekend admissions, holiday season admissions were associated with a 24%, 30%, and 22% increased risk of in-hospital, 7-day, and 30-day mortality, respectively. However, mortality did not differ significantly between weekend and weekday admissions. Subanalyses after stratification for age, sex, and stroke type also revealed similar trends. Conclusions We report for the first time a "holiday season effect" on stroke mortality. Patients admitted during holiday seasons had higher mortality risks than those admitted on weekends and weekdays. This holiday season effect persisted even after adjusting for stroke severity and other important confounders. These findings highlight the need for healthcare delivery systems with a consistent quality of round-the-clock care for patients admitted for stroke.

Risk of Psychiatric Morbidity in Psychosexual Disorders in Male Patients: A Nationwide, Cohort Study in Taiwan

This study aimed to investigate the association between males with psychosexual disorders (PSDs) and the risk of developing psychiatric disorders. A total of 34,972 enrolled patients, with 8,743 subjects who had suffered from PSD and 26,229 controls (1:3) matched for age and index year, from Taiwan’s Longitudinal Health Insurance Database (LHID) from 2000 to 2015, selected from the National Health Insurance Research Database (NHIRD). After adjusting all the confounding factors, the multivariate Cox regression model was used to compare the risk of developing psychiatric disorders, between the PSD and non-PSD groups, during the 15 years of follow-up. Of the all enrollees, 1,113 in the PSD cohort and 2,611 in the non-PSD cohort (1,180.96 vs. 954.68 per 100,000 person-year) developed psychiatric disorders. Multivariate Cox regression model survival analysis revealed that, after adjusting for gender, age, monthly income, urbanization level, geographic region, and comorbidities, the adjusted hazard ratio (HR) was 2.448 (95% CI [2.227, 2.633], p < .001). PSD has been associated with the increased risk in anxiety disorders, depressive disorders, bipolar disorders, sleep disorders, and psychotic disorders, respectively. Sexual dysfunctions, paraphilia, and gender identity disorders were associated with the overall psychiatric disorders with adjusted HRs as 1.990 (p < .001), 11.622 (p < .001), and 5.472 (p < .001), respectively. Male patients who suffered from PSD have a higher risk of developing psychiatric disorders, and this finding should be considered as a timely reminder for the clinicians to provide much more attention for these patients because of their mental health issues.

Association between initial dialytic modalities and the risks of mortality, infection death, and cardiovascular events: A nationwide population-based cohort study

To date, few studies have been conducted to pairwise compare the prognosis of peritoneal dialysis (PD), unplanned PD, and unplanned hemodialysis (HD). We analyzed longitudinal data from Taiwan’s National Health Insurance Research Database. We included 45,165 patients whose initial dialytic modality was PD or unplanned HD between January 1, 2001 and December 31, 2013. We divided the patients into three groups according to their initial dialytic modalities. The primary outcomes were all-cause mortality and death from infection during 1-year follow up. The risks of all-cause mortality and infection death were higher in the unplanned PD group than in the planned PD group (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.28–1.60; HR 1.54, 95% CI 1.32–1.80). Likewise, the risks of all-cause mortality and infection death were higher in the unplanned HD group (HR 1.64, 95% CI 1.48–1.82; HR 1.85, 95% CI 1.61–2.13). Furthermore, the risks of all-cause mortality and infection death were also higher in the unplanned HD group than in the unplanned PD group (HR 1.15, 95% CI 1.07–1.23; HR 1.20, 95% CI 1.09–1.32). In conclusion, our study demonstrates that patients whose initial modality was planned PD or unplanned PD may have better clinical outcomes than those whose initial modality was unplanned HD.

Involvement of swallowing therapy is associated with improved long-term survival in patients with post-stroke dysphagia

BACKGROUND

The effects of swallowing therapy (ST) on long-term clinical outcomes in patients with post-stroke dysphagia (PSD) remain unclear.

AIM

This study explores the effect of ST, initiated within 6 months of the stroke onset, on long-term pneumonia-free and overall survival rates in PSD patients.

DESIGN

Retrospective cohort study.

SETTING

Longitudinal Health Insurance Database.

POPULATION

The study included 2994 eligible PSD patients between 2005 and 2013.

METHODS

Among the scrutinized PSD patients, ST was initiated during the nasogastric intubation (NGI) period and was implemented by physician discretion. Therefore, subjects who underwent ST were classified into the ST-intervention (STI) group and those without ST were classified into the non-ST (NST) group. Propensity score matching (PSM) was used to match age, sex, pneumonia events during the NGI period, the Charlson comorbidity index, and the National Institutes of Health Stroke Scale between the two groups. We started to follow all selected PSD patients 6 months after the onset of stroke for four years. Multivariable adjusted Cox regression and Kaplan-Meier estimations were conducted to assess the effects of ST and the ST duration on pneumonia-free and overall survival.

RESULTS

Overall, 1497 PSD patients aged approximately 68 years in each group were selected in this study. The pneumonia-free survival rate in STI subjects was 57.4% and was significantly greater (P=0.003) than that (54.2%) in NST subjects during the follow-up (F/U). A significantly improved (P<0.0001) overall survival rate was observed in STI subjects (75.0%) compared to NST subjects (63.7%) during the F/U. In STI subjects, ST duration ≥ 1 month was significantly (P=0.009) associated with reduced pneumonia incidence compared to those with ST duration<1 month.

CONCLUSIONS

Participation of ST within 6 months of the stroke onset is associated with decreased pneumonia incidence and improved long-term survival in selected PSD patients. In the selected STI subjects, longer ST duration may be valuable in pneumonia prevention.

CLINICAL REHABILITATION IMPACT

This study reveals that ST initiated within 6 months of the stroke onset may be associated with improved long-term survival in selected PSD patients.

Hospital Volume Threshold Associated with Higher Survival after Endovascular Recanalization Therapy for Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Endovascular recanalization therapy (ERT) is becoming increasingly important in the management of acute ischemic stroke (AIS). However, the hospital volume threshold for optimal ERT remains unknown. We investigated the relationship between hospital volume of ERT and risk-adjusted patient outcomes.

METHODS

From the National Health Insurance claims data in Korea, 11,745 patients with AIS who underwent ERT from July 2011 to June 2016 in 111 hospitals were selected. We measured the hospital's ERT volume and patient outcomes, including the 30-day mortality, readmission, and postprocedural intracranial hemorrhage (ICH) rates. For each outcome measure, we constructed risk-adjusted prediction models incorporating demographic variables, the modified Charlson comorbidity index, and the stroke severity index (SSI), and validated them. Risk-adjusted outcomes of AIS cases were compared across hospital quartiles to confirm the volume-outcome relationship (VOR) in ERT. Spline regression was performed to determine the volume threshold.

RESULTS

The mean AIS volume was 14.8 cases per hospital/year and the unadjusted means of mortality, readmission, and ICH rates were 11.6%, 4.6%, and 8.6%, respectively. The VOR was observed in the risk-adjusted 30-day mortality rate across all quartile groups, and in the ICH rate between the first and fourth quartiles (P<0.05). The volume threshold was 24 cases per year.

CONCLUSIONS

There was an association between hospital volume and outcomes, and the volume threshold in ERT was identified. Policies should be developed to ensure the implementation of the AIS volume threshold for hospitals performing ERT.

Risk Factors Associated with Outcomes of Recombinant Tissue Plasminogen Activator Therapy in Patients with Acute Ischemic Stroke

Ischemic stroke is the most common type of stroke, and early interventional treatment is associated with favorable outcomes. In the guidelines, thrombolytic therapy using recombinant tissue-type plasminogen activator (rt-PA) is recommended for eligible patients with acute ischemic stroke. However, the risk of hemorrhagic complications limits the use of rt-PA, and the risk factors for poor treatment outcomes need to be identified. To identify the risk factors associated with in-hospital poor outcomes in patients treated with rt-PA, we analyzed the electronic medical records of patients who were diagnosed with acute ischemic stroke and treated for rt-PA at Chang Gung Memorial Hospitals from 2006 to 2016. In-hospital death, intensive care unit (ICU) stay, or prolonged hospitalization were defined as unfavorable treatment outcomes. Medical history variables and laboratory test results were considered variables of interest to determine risk factors. Among 643 eligible patients, 537 (83.5%) and 106 (16.5%) patients had favorable and poor outcomes, respectively. In the multivariable analysis, risk factors associated with poor outcomes were female gender, higher stroke severity index (SSI), higher serum glucose levels, lower mean corpuscular hemoglobin concentration (MCHC), lower platelet counts, and anemia. The risk factors found in this research could help us study the treatment strategy for ischemic stroke.

Development of a novel score to predict newly diagnosed atrial fibrillation after ischemic stroke: The CHASE-LESS score

BACKGROUND AND AIMS

Prompt detection of atrial fibrillation (AF) is essential for optimal secondary stroke prevention, but routine long-term cardiac monitoring of all ischemic stroke patients is neither practical nor affordable. We aimed to develop and validate a risk score to identify patients at risk for newly diagnosed AF (NDAF) after ischemic stroke.

METHODS

Information on adult patients hospitalized for ischemic stroke without known AF was retrieved from a nationwide database. Primary outcome was NDAF within one year following index stroke. A stepwise Cox model was used to screen for predictors. Beta coefficients for the independent predictors were converted to integer points, which were summed to create a risk score.

RESULTS

We identified 4 positive predictors and 3 negative predictors. The CHASE-LESS score (Coronary, Heart failure, Age, stroke SEverity, - LipidEmia, Sugar, prior Stroke) comprises coronary artery disease (1 point), congestive heart failure (1 point), age (1 point for every 10 years), stroke severity (National Institutes of Health Stroke Scale; 1 point for 6-13 and 4 points for ≥14), hyperlipidemia (-1 point), diabetes (-1 point), and prior history of stroke or transient ischemic attack (-1 point). Overall, 6.0% (1029/17,076) of patients developed NDAF. The incidence rate ranged from 8/1000 person-years (CHASE-LESS ≤3) to 240/1000 person-years (CHASE-LESS ≥10). The model achieved a c-index of 0.730 in the development cohort and 0.732 in the validation cohort.

CONCLUSIONS

The CHASE-LESS score could aid clinicians to identify patients at risk of developing NDAF and help prioritize patients for advanced cardiac monitoring.

Assessing stroke severity using electronic health record data: a machine learning approach

Background

Stroke severity is an important predictor of patient outcomes and is commonly measured with the National Institutes of Health Stroke Scale (NIHSS) scores. Because these scores are often recorded as free text in physician reports, structured real-world evidence databases seldom include the severity. The aim of this study was to use machine learning models to impute NIHSS scores for all patients with newly diagnosed stroke from multi-institution electronic health record (EHR) data.

Methods

NIHSS scores available in the Optum© de-identified Integrated Claims-Clinical dataset were extracted from physician notes by applying natural language processing (NLP) methods. The cohort analyzed in the study consists of the 7149 patients with an inpatient or emergency room diagnosis of ischemic stroke, hemorrhagic stroke, or transient ischemic attack and a corresponding NLP-extracted NIHSS score. A subset of these patients (n = 1033, 14%) were held out for independent validation of model performance and the remaining patients (n = 6116, 86%) were used for training the model. Several machine learning models were evaluated, and parameters optimized using cross-validation on the training set. The model with optimal performance, a random forest model, was ultimately evaluated on the holdout set.

Results

Leveraging machine learning we identified the main factors in electronic health record data for assessing stroke severity, including death within the same month as stroke occurrence, length of hospital stay following stroke occurrence, aphagia/dysphagia diagnosis, hemiplegia diagnosis, and whether a patient was discharged to home or self-care. Comparing the imputed NIHSS scores to the NLP-extracted NIHSS scores on the holdout data set yielded an R² (coefficient of determination) of 0.57, an R (Pearson correlation coefficient) of 0.76, and a root-mean-squared error of 4.5.

Conclusions

Machine learning models built on EHR data can be used to determine proxies for stroke severity. This enables severity to be incorporated in studies of stroke patient outcomes using administrative and EHR databases.

Pioglitazone and PPAR-γ modulating treatment in hypertensive and type 2 diabetic patients after ischemic stroke: a national cohort study

Background and aim

Peroxisome proliferator-activated receptor-γ (PPAR-γ) modulating treatment may have cardiovascular benefits in type 2 diabetes mellitus (T2DM) patients after ischemic stroke (IS). However, whether there are additional benefits from intensive PPAR-γ modulating treatments in Asian patients with T2DM and hypertension (HTN) after IS remains unknown.

Methods

Between 2001 and 2013, patients admitted due to IS were identified from the National Health Insurance Research Database of Taiwan. Patients with T2DM and HTN using angiotensin receptor blockers were further included. Eligible patients were divided into two groups: (1) pioglitazone and (2) non-pioglitazone oral anti-diabetic agent groups. Propensity score matching (1:2) was used to balance the distribution of baseline characteristics, stroke severity and medications. The primary outcome was recurrent IS. Subgroup analysis for recurrent IS in pioglitazone and/or telmisartan users, the trend of IS risks across different PPAR-γ intensity treatments, and dose-dependent outcomes across different pioglitazone possession ratios were further studied. Statistical significance was set at p < 0.05 and p < 0.1 for clinical outcomes and interaction of subgroup analyses, respectively.

Results

There were 3190 and 32,645 patients in the pioglitazone and non-pioglitazone groups. Patients of the pioglitazone group had a lower risk of recurrent IS (subdistribution hazard ratio, 0.91; 95% confidence interval 0.84–0.99). Pioglitazone was also associated with reduced recurrent IS in patients who also used telmisartan (p for interaction = 0.071). A graded correlation was found a borderline significant trend between the intensity of PPAR-γ therapy and following IS (p = 0.076). The dose-dependent outcome also showed that a borderline significant trend that higher pioglitazone possession ratio was associated with a lower risk of recurrent IS (p = 0.068).

Conclusions

The current study suggests that the use of pioglitazone in type 2 diabetic and hypertensive IS patients is associated with fewer recurrent IS events in an Asian population. Concurrent telmisartan use or a higher pioglitazone possession ratio may have a trend of increased pleiotropic effects, which could possibly be related to higher PPAR-γ effects. Future studies are warranted to confirm or refute the clinical effects and the possible mechanism of more intensive PPAR-γ-modulating treatments.

Test-retest reliability of the Mini Nutritional Assessment and its relationship with quality of life in patients with stroke

BACKGROUND & OBJECTIVE

Malnutrition is one of commonly issues in patients with stroke. The Mini Nutritional Assessment (MNA) is a widely used measure for assessing nutritional status in patients with stroke. A nutritional measure with acceptable test-retest reliability allows clinicians to consistently assess patients' nutritional status. Knowledge of the relationship between nutritional status and quality of life (QOL) could guide clinicians to improve QOL in patients with stroke more effectively. This study aimed to examine test-retest reliability of the MNA and its relationship with QOL in patients with stroke.

METHODS

Fifty-nine patients participated in the test-retest reliability study and the correlation between the MNA and WHO Quality of Life-BREF (WHOQOL-BREF) study. A repeated-assessments design (1 week apart) was used to examine the test-retest reliability of the MNA.

RESULTS

The intraclass correlation coefficient for the MNA was 0.91. The minimal detectable change and percentage of minimal detectable change for the MNA were 2.1 and 8.2%, respectively. The MNA was positively associated with the QOL (r = 0.32; p = 0.013). The result of linear regression analysis shows that after controlling for age, sex and activities of daily living functions, only the MNA was significantly associated with the WHOQOL-BREF (r2 = 0.104; p = 0.008).

CONCLUSIONS

The MNA has satisfactory test-retest reliability that is useful for repeatedly assessing the nutritional status of patients with stroke. The MDC of the MNA has acceptable random measurement error which is useful for determining whether the change score of a patient is outside the range of random measurement error. Future studies that recruit stroke patients in the acute stage is needed to further examine the relationship between the nutritional status and QOL.

Taiwan's National Health Insurance Research Database: past and future

Taiwan's National Health Insurance Research Database (NHIRD) exemplifies a population-level data source for generating real-world evidence to support clinical decisions and health care policy-making. Like with all claims databases, there have been some validity concerns of studies using the NHIRD, such as the accuracy of diagnosis codes and issues around unmeasured confounders. Endeavors to validate diagnosed codes or to develop methodologic approaches to address unmeasured confounders have largely increased the reliability of NHIRD studies. Recently, Taiwan's Ministry of Health and Welfare (MOHW) established a Health and Welfare Data Center (HWDC), a data repository site that centralizes the NHIRD and about 70 other health-related databases for data management and analyses. To strengthen the protection of data privacy, investigators are required to conduct on-site analysis at an HWDC through remote connection to MOHW servers. Although the tight regulation of this on-site analysis has led to inconvenience for analysts and has increased time and costs required for research, the HWDC has created opportunities for enriched dimensions of study by linking across the NHIRD and other databases. In the near future, researchers will have greater opportunity to distill knowledge from the NHIRD linked to hospital-based electronic medical records databases containing unstructured patient-level information by using artificial intelligence techniques, including machine learning and natural language processes. We believe that NHIRD with multiple data sources could represent a powerful research engine with enriched dimensions and could serve as a guiding light for real-world evidence-based medicine in Taiwan.

Association between continuity of care and long-term mortality in Taiwanese first-ever stroke survivors: An 8-year cohort study

Background

Continuity of care is considered to be an important principle of stroke care; however, few analyses of empirically related outcomes have been reported.

Objective

This study examined the correlation between the continuity of care for outpatients after a stroke event and the survival of stroke patients over the year following hospital discharge.

Research design

Data from the Taiwan National Health Insurance Database were used in this study. We defined stroke as the ICD-9-CM codes 430 to 437, and all patients were followed up regarding their survival for at least one year. The modified modified continuity index (MMCI) was used as the indicator of continuity of care. Cox proportional hazard models with robust sandwich variance estimates were employed to analyze the correlation between continuity of care and stroke-related death.

Results

A total of 9,252 stroke patients were included in the analysis. Those patients who had a high and a completed COC had a higher percentage of survival (97.25% and 95.39%) compared to the other two groups. After controlling for other variables, compared with the low-level continuity of care group, the moderate-level, high-level and completed continuity of care groups still showed a significantly lower risk of death HR (95% CI) were: 0.63 (0.49–0.80), 0.56 (0.40–0.79) and 0.50 (0.39–0.63), respectively.

Conclusion

Continuity of care may increase the survival among stroke patients and therefore plays an important role in management of stroke after survival.

Taiwan's National Health Insurance Research Database: past and future

Taiwan’s National Health Insurance Research Database (NHIRD) exemplifies a population-level data source for generating real-world evidence to support clinical decisions and health care policy-making. Like with all claims databases, there have been some validity concerns of studies using the NHIRD, such as the accuracy of diagnosis codes and issues around unmeasured confounders. Endeavors to validate diagnosed codes or to develop methodologic approaches to address unmeasured confounders have largely increased the reliability of NHIRD studies. Recently, Taiwan’s Ministry of Health and Welfare (MOHW) established a Health and Welfare Data Center (HWDC), a data repository site that centralizes the NHIRD and about 70 other health-related databases for data management and analyses. To strengthen the protection of data privacy, investigators are required to conduct on-site analysis at an HWDC through remote connection to MOHW servers. Although the tight regulation of this on-site analysis has led to inconvenience for analysts and has increased time and costs required for research, the HWDC has created opportunities for enriched dimensions of study by linking across the NHIRD and other databases. In the near future, researchers will have greater opportunity to distill knowledge from the NHIRD linked to hospital-based electronic medical records databases containing unstructured patient-level information by using artificial intelligence techniques, including machine learning and natural language processes. We believe that NHIRD with multiple data sources could represent a powerful research engine with enriched dimensions and could serve as a guiding light for real-world evidence-based medicine in Taiwan.

Chronic Kidney Disease Worsens Health Outcomes in Diabetic Patients After Hip Fracture Surgery: An Asian Nationwide Population-Based Cohort Study

There is an increased tendency for hip fractures in patients with chronic kidney disease (CKD). Although surgery is the mainstay of treatment for hip fractures, there is scant information on outcomes after hip fracture surgery in diabetic patients at different stages of CKD. In this population-based cohort study, we compared the surgical outcome, readmission, and mortality rates after osteosynthesis of hip fractures in diabetic patients with different stages of renal function. Diabetic patients who received primary osteosynthesis for hip fracture between January 1997 and December 2013 were enrolled. The primary outcomes were surgical outcomes, including infection and revision surgery. The secondary outcomes were all-cause readmission and mortality. This study included 44,065 patients; 11,954 had CKD (diabetic CKD group), 1662 patients were receiving dialysis (diabetic dialysis group), and 30,449 patients had no CKD (diabetic non-CKD group). We found that the diabetic dialysis group had a significantly higher risk of infection and revision surgery compared with diabetic non-CKD patients (HR = 1.52, 95% CI, 1.24 to 1.87; HR = 1.62, 95% CI, 1.33 to 1.97, respectively, both P < 0.001) and diabetic CKD patients (HR = 1.62, 95% CI, 1.32 to 1.99; HR = 1.48, 95% CI, 1.22 to 1.80, respectively, both P < 0.001). Diabetic CKD patients had a comparable risk of surgical complications including infection and revision as diabetic non-CKD patients. For readmission and mortality, the diabetic dialysis group had the highest risk among the three groups at all time-points (3 months after surgery, 1 year, and the last follow-up, all P < 0.001). Compared with the diabetic non-CKD group, the diabetic CKD group had an elevated risk of readmission and mortality at all time-points (all P < 0.001). In conclusion, CKD was associated with worse outcomes after hip fracture fixation surgery. Although at significantly higher risk of readmission and mortality, CKD patients still had a comparable risk of infection and revision to non-CKD patients. © 2019 American Society for Bone and Mineral Research.

Unrecognized History of Transient Atrial Fibrillation at the Time of Discharge from an Index Stroke Hospitalization Is Associated with Increased Recurrent Stroke Risk

Background and Purpose

Preceding episodes of paroxysmal atrial fibrillation (AF) among stroke patients can be easily overlooked in routine clinical practice. We aim to determine whether an unrecognized history of paroxysmal AF is associated with an increased risk of recurrent stroke.

Methods

We retrospectively identified all adult patients hospitalized with a primary diagnosis of ischemic stroke who had no AF diagnosis on their discharge records, using the Taiwan National Health Insurance Research Database between January 2001 and December 2012. Patients were categorized into two groups: unrecognized AF history and no AF. Patients with unrecognized AF history were defined as having documented AF preceding the index ischemic stroke hospitalization, but not recording at the index ischemic stroke. Primary endpoint was recurrent stroke within 1 year after the index stroke.

Results

Among 203,489 hospitalized ischemic stroke patients without AF diagnosed at discharge, 6,731 patients (3.3%) had an unrecognized history of prior transient AF. Patients with an unrecognized AF history, comparing to those without AF, had higher adjusted risk of all recurrent stroke ([original cohort: hazard ratio (HR), 1.41; 95% confidence interval [CI], 1.30 to 1.53], [matched cohort: HR, 1.51; 95% CI, 1.37 to 1.68]) and recurrent ischemic stroke ([original cohort: HR, 1.42; 95% CI, 1.30 to 1.55], [matched cohort: HR, 1.56; 95% CI, 1.40 to 1.74]) during the 1-year follow-up period.

Conclusions

Unrecognized history of AF among patients discharged after an index ischemic stroke hospitalization is associated with higher recurrent stroke risk. Careful history review to uncover a paroxysmal AF history is important for ischemic stroke patients.

Association between benzodiazepine use and risks of chronic-onset poststroke pneumonia: a population-based cohort study

OBJECTIVES

To investigate the association between benzodiazepine (BZD) use and the risk of chronic-onset poststroke pneumonia.

DESIGN

Population-based propensity-matched retrospective cohort study.

SETTING

Taiwan's National Health Insurance Research Database.

PARTICIPANTS

Patients newly diagnosed with stroke between 2000 and 2012 were identified and, after propensity score matching, 7516 patients were enrolled. Among these, 3758 patients received BZDs after stroke while 3758 did not.

OUTCOME MEASURES

HRs for developing pneumonia over 1 month after stroke according to BZD use were assessed using Cox proportional hazards regression models. Analyses according to cumulative defined daily doses (cDDDs) of BZDs and stratification for age and sex were also performed.

RESULTS

During a mean follow-up time of 4.4 years, 1027 patients in the BZD cohort and 478 patients in the non-BZD cohort developed pneumonia over 1 month after stroke. Patients using BZDs after stroke had a higher pneumonia risk than did those not using BZDs (52.2vs32.6 per 1000 person-years, adjusted HR (aHR)=2.21, 95% CI (CI)=1.97 to 2.48, p<0.001). Analyses based on cumulative BZD dose revealed that all BZD user subgroups were associated with a higher risk of pneumonia. The aHRs for patients taking 1-90, 91-365 and >365 cDDDs of BZDs were 2.28 (95% CI=2.01 to 2.58; p<0.001), 2.09 (95% CI=1.77 to 2.47; p<0.001) and 2.08 (95% CI=1.72 to 2.52; p<0.001), respectively. The significant association between BZD use and increased pneumonia risk persisted even after stratifying subgroups by age and sex.

CONCLUSIONS

BZD use is associated with an increased risk of chronic-onset poststroke pneumonia.