Abstract WP40: Development Of The System For National Statistics Of Stroke And Acute Myocardial Infarction Using Claims-based Algorithms In Korea

Abstract

Background: The epidemiology of stroke and acute myocardial infarction (AMI) in Korea is limited by inaccurate methods for estimating incidence. Therefore, this study aimed to build the system for national statistics of stroke and AMI in Korea using claims-based identification algorithms. Methods: We identified stroke and AMI using the claims-based algorithms based on the 2018 National Health Insurance Service (NHIS) data. The identification algorithms were validated using investigation of medical records of the sampled cases including the patient groups and the control groups based on a 2-stage stratified sampling method. The sampled cases were divided into 6 strata according to regions (capital and non-capital) and types of centers (tertiary hospitals, general hospitals, and hospitals). Based on the medical records results, we calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and weighted PPV and weighted NPV were calculated by applying strata-specific sampling rates. The incidence rate of stroke and AMI is the number of new cases of stroke and AMI, including recurrent events, which was calculated by applying the algorithms using weighted PPV and NPV to the claims data. Results: In total, 2,200 cases (1,086 cases in stroke [578 patients and 508 controls] and 1,114 cases in AMI [520 patients and 594 controls]) were sampled after applying algorithms for review of hospital records. In hospital record reviews, the stroke algorithm had 95.2% sensitivity, 99.6% specificity, 89.3% PPV, and 99.8% NPV, and AMI algorithms showed 97.7% sensitivity, 99.9% specificity, 90.0% PPV, and 99.9% NPV. We identified 94,994 stroke and 33,834 AMI cases including recurrent events using validated identification algorithms in 2018. The age- and sex-standardized incidence rate of stroke was 175.7 cases per 100,000 person-years and the incidence rate of AMI was 49.3 cases per 100,000 person-years in 2018. Conclusion: We developed the national statistical system to estimate the incidence of stroke and AMI using validated claims-based algorithms in Korea. By using this system, we expect that it will be possible to conduct nationwide epidemiological research and improve acute cardiovascular care in Korea.