Validating the diagnosis of acute ischemic stroke in a National Health Insurance claims database

A trial fibrillation (AF) confers a 5-fold increased risk of stroke compared with patients without AF. 1 The risk of AF-associated stroke is not homogeneous and depends on patients' age and comorbidities, which have resulted in the development of clinical scores to aid stroke risk stratification and guide the use of oral anticoagulation (OAC) for stroke prevention. Currently, the CHA 2 DS 2 -VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female) score is recommended by guidelines for stroke risk stratification in AF 2,3 and has been shown to be better than the older CHADS 2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score for stroke risk stratification among Asian AF patients. 4 Because age is an important driver of ischemic stroke for AF patients, 5 the CHA 2 DS 2 -VASc scheme assigns 1 point forBackground and Purpose-The age threshold for an increased stroke risk for patients with atrial fibrillation may be different for Asians and non-Asians. We hypothesized that a modified CHA 2 DS 2 -VASc (congestive heart failure, hypertension, age ≥75, diabetes mellitus, prior stroke or transient ischemic attack, vascular disease, age 65-74 years, female) scheme, mCHA 2 DS 2 -VASc, which assigned one point for patients aged 50 to 74 years, may perform better than CHA 2 DS 2 -VASc score for stroke risk stratification in Asians. Methods-This study used the Taiwan National Health Insurance Research Database, which included 224 866 newly diagnosed atrial fibrillation patients. The predictive accuracies of ischemic stroke of CHA 2 DS 2 -VASc and mCHA 2 DS 2 -VASc scores were compared among 124 271 patients without antithrombotic therapies. From the whole cohort, 15 948 patients had a CHA 2 DS 2 -VASc score 0 (males) or 1 (females), and 8654 patients had an mCHA 2 DS 2 -VASc score 1 (males) or 2 (females). The latter were categorized into 3 groups, that is, no treatment, antiplatelet therapy, and warfarin, and the risks of ischemic stroke and intracranial hemorrhage (ICH) were compared. Results-During a follow-up of 538 653 person-years, 21 008 patients experienced ischemic stroke. The mCHA 2 DS 2 -VASc performed better than CHA 2 DS 2 -VASc score in predicting ischemic stroke assessed by C indexes and net reclassification index. For 8654 patients having an mCHA 2 DS 2 -VASc score of 1 (males) or 2 (females) because of the resetting of the age threshold, use of warfarin was associated with a 30% lower risk of ischemic stroke and a similar risk of ICH compared with nontreatment. Net clinical benefit analyses also favored the use of warfarin in different weighted models. patients aged between 65 and 74 years and 2 points for those aged ≥75 years. 6 However, the age threshold for an increased risk of ischemic stroke for Asians may be lower than that of Caucasians. Conclusions-In7 For Asian AF patients with a CHA 2 DS 2 -VASc score of 0 (males)...

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“…18 The principal safety end point was the occurrence of intracranial hemorrhage (ICH), necessitating admissions to intensive care units.…”

Section: Definition Of Clinical End Point and Calculation Of Net Clinmentioning

confidence: 99%

Validation of a Modified CHA ₂ DS ₂ -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Chao

Lip

Liu

et al. 2016

Stroke

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“…First, the diagnosis of AF and the occurrence of ischemic stroke were based on the diagnostic codes registered by the physicians responsible for the treatment of patients; nonetheless, the accuracy of the diagnosis of AF and ischemic stroke in Taiwan's NHIRD has been validated previously as high 12, 13, 15, 16. We defined patients as having AF only when it was a discharge diagnosis or was confirmed on at least 2 occasions in the outpatient department.…”

Section: Discussionmentioning

confidence: 99%

Is an Oral Anticoagulant Necessary for Young Atrial Fibrillation Patients With a CHA ₂ DS ₂ ‐VASc Score of 1 (Men) or 2 (Women)?

Hung

Chao

Liu

et al. 2016

JAHA

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BackgroundRecent studies demonstrated that oral anticoagulants (OACs) should be considered for patients with atrial fibrillation and 1 risk factor in addition to sex. Because age is an important determinant of ischemic stroke, the strategy for stroke prevention may be different for these patients in different age strata. The aim of this study was to investigate whether OACs should be considered for patients aged 20 to 49 years with atrial fibrillation and a CHA2DS2‐VASc score of 1 (men) or 2 (women).Methods and ResultsUsing the Taiwan National Health Insurance Research Database, 7374 male patients with atrial fibrillation and a CHA2DS2‐VASc score of 1 and 4461 female patients with atrial fibrillation and a CHA2DS2‐VASc score of 2 and all without antithrombotic therapies were identified and stratified into 3 groups by age. The threshold for the initiation of OACs for stroke prevention was set at a stroke rate of 1.7% per year for warfarin and 0.9% per year for non–vitamin K antagonist OACs. Among male patients aged 20 to 49 years with a CHA2DS2‐VASc score of 1, the risk of ischemic stroke was 1.30% per year and ranged from 0.94% per year for those with hypertension to 1.71% for those with congestive heart failure. Among female patients aged 20 to 49 years with a CHA2DS2‐VASc score of 2, the risk of ischemic stroke was 1.40% per year and ranged from 1.11% per year for those with hypertension to 1.67% for those with congestive heart failure.ConclusionsFor atrial fibrillation patients aged 20 to 49 years with 1 risk factor in addition to sex, non–vitamin K antagonist OACs should be considered for stroke prevention to minimize the risk of a potentially fatal or disabling event.

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“…First, potential disease misclassifications may exist because the diagnoses of diabetes and HCE as well as the comorbidities relied solely on the claims data. However, many studies have proven that NHIRD claim data are highly accurate and appear to be a valid resource for population research (20)(21)(22). Therefore, the misclassifications should be minimal and thus unlikely to introduce remarkable effects on the results of our study.…”

Section: Discussionmentioning

confidence: 99%

Long-term Mortality Risk After Hyperglycemic Crisis Episodes in Geriatric Patients With Diabetes: A National Population-Based Cohort Study

et al. 2015

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OBJECTIVEHyperglycemic crisis is one of the most serious diabetes-related complications. The increase in the prevalence of diabetes in the geriatric population leads to a large disease burden, but previous studies of geriatric hyperglycemic crisis were focused on acute hyperglycemic crisis episode (HCE). This study aimed to delineate the long-term mortality risk after HCE. RESEARCH DESIGN AND METHODSThis retrospective national population-based cohort study reviewed, in Taiwan's National Health Insurance Research Database, data from 13,551 geriatric patients with new-onset diabetes between 2000 and 2002, including 4,517 with HCE (case subjects) (ICD-9 code 250.1 or 250.2) and 9,034 without HCE (control subjects). The groups were compared and followed until 2011. RESULTSOne thousand six hundred thirty-four (36.17%) case and 1,692 (18.73%) control subjects died (P < 0.0001) during follow-up. Incidence rate ratios (IRRs) of death were 2.82 times higher in case subjects (P < 0.0001). The mortality risk was highest in the first month (IRR 26.56; 95% CI 17.97-39.27) and remained higher until 4-6 years after the HCE (IRR 1.49; 95% CI 1.23-1.81). After adjustment for age, sex, selected comorbidities, and monthly income, the mortality hazard ratio was still 2.848 and 4.525 times higher in case subjects with one episode and two or more episodes of hyperglycemic crisis, respectively. Older age, male sex, renal disease, stroke, cancer, chronic obstructive pulmonary disease, and congestive heart failure were independent mortality predictors. CONCLUSIONSPatients with diabetes had a higher mortality risk after HCE during the first 6 years of follow-up. Referral for proper education, better access to medical care, effective communication with a health care provider, and control of comorbidities should be done immediately after HCE.

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Validating the diagnosis of acute ischemic stroke in a National Health Insurance claims database

Abstract: The PPV of a diagnosis of AIS in the NHI claims data was high. Using five-digit ICD-9 codes to identify AIS cases will markedly decrease the false-positive rate compared with using the commonly used three-digit method.

Cited by 329 publications

References 10 publications

Validation of a Modified CHA ₂ DS ₂ -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Validation of a Modified CHA ₂ DS ₂ -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Is an Oral Anticoagulant Necessary for Young Atrial Fibrillation Patients With a CHA ₂ DS ₂ ‐VASc Score of 1 (Men) or 2 (Women)?

Long-term Mortality Risk After Hyperglycemic Crisis Episodes in Geriatric Patients With Diabetes: A National Population-Based Cohort Study

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Validating the diagnosis of acute ischemic stroke in a National Health Insurance claims database

Abstract: The PPV of a diagnosis of AIS in the NHI claims data was high. Using five-digit ICD-9 codes to identify AIS cases will markedly decrease the false-positive rate compared with using the commonly used three-digit method.

Cited by 329 publications

References 10 publications

Validation of a Modified CHA 2 DS 2 -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Validation of a Modified CHA 2 DS 2 -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Is an Oral Anticoagulant Necessary for Young Atrial Fibrillation Patients With a CHA 2 DS 2 ‐VASc Score of 1 (Men) or 2 (Women)?

Long-term Mortality Risk After Hyperglycemic Crisis Episodes in Geriatric Patients With Diabetes: A National Population-Based Cohort Study

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Validation of a Modified CHA ₂ DS ₂ -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Validation of a Modified CHA ₂ DS ₂ -VASc Score for Stroke Risk Stratification in Asian Patients With Atrial Fibrillation

Is an Oral Anticoagulant Necessary for Young Atrial Fibrillation Patients With a CHA ₂ DS ₂ ‐VASc Score of 1 (Men) or 2 (Women)?