Korean National Health Information Database Research Articles

Cardiovascular Research Using the Korean National Health Information Database.

The Korean National Health Information Database (NHID) contains nationwide claims data, including sociodemographic data, health care utilization, health screening data, and healthcare provider information. To compensate for the limitations of randomized clinical trials, real-world observational studies using claims data have emerged as a novel research tool. We summarized the structure of the Korean NHID and the recent researches conducted in the field of cardiovascular science. Epidemiological studies, prescription patterns, temporal trends, comparison of effectiveness and safety of treatments, variability index using laboratory data, and rare intractable disease constitute interesting topics of research in cardiovascular science using the NHID. The operational definition of covariates and clinical outcomes is important for researchers interested in using the NHID data as new tools to prove their hypothesis. A step-by-step approach adopted by a team of data scientists, epidemiologists, statisticians, and clinical researchers may be most effective while designing research studies. The ultimate direction of research using the NHID should aim to improve the welfare of the public by promoting public health, reducing medical costs, and guiding healthcare policies.

Outcomes for Inappropriate Renal Dose Adjustment of Dipeptidyl Peptidase-4 Inhibitors in Patients With Type 2 Diabetes Mellitus: Population-Based Study

ObjectivesTo estimate inappropriate dosing of dipeptidyl peptidase-4 (DPP-4) inhibitors and to assess the risk of emergency department visits, hypoglycemia, and mortality in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD) prescribed inappropriate DPP-4 inhibitor doses because limited real-world information is available regarding rates of DPP-4 inhibitor dose adjustment and its safety in patients with T2DM and CKD. Patients and MethodsWe performed a retrospective observational cohort study of 82,332 patients aged 30 to 75 years with T2DM and CKD being treated with DPP-4 inhibitors from January 1, 2012, through December 31, 2014, using the Korean National Health Information Database. We divided the patients according to the prescription of DPP-4 inhibitor with or without dose adjustment according to estimated glomerular filtration rate. The incidences of emergency department visits, hypoglycemia, and mortality were assessed using hazard ratios estimated using Cox proportional hazards regression modeling. ResultsApproximately 40% of patients with T2DM and CKD were prescribed an inappropriate dose of DPP-4 inhibitor from 2009 through 2011; this proportion decreased to 24.4% in 2015. Hazard ratios (95% CIs) for inappropriate vs appropriate dosing of DPP-4 inhibitors were 1.115 (1.005-1.237) for mortality, 1.074 (1.018-1.133) for emergency department visits, and 1.192 (1.054-1.349) for severe hypoglycemia after multivariable adjustment for confounding factors. ConclusionOne of every 3 patients with T2DM and CKD received inappropriate dosing of DPP-4 inhibitor, which was associated with high risk of emergency department visits, severe hypoglycemia, and mortality.

Association between ambient fine particulate matter and seasonal variation in acute myocardial infarction morbidity

TPS 683: Short-term health effects of air pollutants 2, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background/Aim: Environmental factors may play a role in the development of cardiovascular diseases and some studies have shown that ambient air pollution is associated with the myocardial infarction. This study was designed to investigate the impact of ambient air pollution on acute myocardial infarction (AMI) among adult over 20 years of age in Korea by using the data from the Korean National Health Information Database (KNHID) Methods: This study used the nationwide, population-based database from the KNHID collected between 2002 and 2015. Data analysis was performed from January 1, 2005 to December 31, 2014 since the ambient fine particulate matter (PM2.5) monitoring data from Seoul Research Institute of Public Health and Environment were available in these periods. Data on 197,940 AMI case counts in Seoul were collected. Meteorological data were collected from the Korea Meteorological Administration (KMA). We used the Poisson regression analysis adjusted for calendar time, current-day temperature, dew-point temperature, relative humidity to explore the association between PM2.5 and AMI. Results: The mean daily PM2.5 concentrations was 25.9μg/m3 with a range from 23.0 to 544μg/m3. In the Poisson regression analysis of PM2.5, the models with lag structures of lag 0 day and 2-day average of lags 0 and 1 (lag01) showed significant association with AMI (RR:1.017, CI:1.008-1.025 for lag0, RR:1.014, CI: 1.005-1.023 for lag01). There were dose-response relationships of PM2.5 concentration and AMI at lag0 and lag01. In the stratified analysis carried out in the cold season (October-April) and warm season (May-September) showed the significant lag 0 effect for AMI cases in the cold season only. Conclusions: In conclusions, our results have demonstrated that the PM2.5 concentration was significantly associated with AMI morbidity at lag 0 in Seoul, Korea. This increased risk was also observed in cold season and future prospective studies are needed to determine the causal association.

Optimal body mass index cutoff point for predicting survival of colorectal cancer in Asian population: A National Health Information Database Analysis.

e13098 Background: A U-shaped relationship between body mass index (BMI) and colorectal cancer mortality has been revealed. However, an optimal BMI range for predicting survival in Asian colorectal cancer patients is unknown. We established the most appropriate cut-off point of BMI for better survival in Asian colorectal cancer patients. Methods: Two cohorts of colorectal cancer patients were included in this study; 5,815 from the Seoul National University Hospital, Korea for development cohort and 54,043 colorectal cancer patients from the Korean National Health Information Database for validation cohort. To determine the optimal cut-off point of BMI at diagnosis, the systematic dichotomization based on log-rank test was performed by the method of Contal and O’Quigley. We evaluated the association between BMI at diagnosis and overall survival (OS) using the Cox proportional hazard model. Results: During a median follow-up of 5.7 years for hospital-based development cohort and 4.3 years for nation-wide validation cohort, 1,180 (20.3%) deaths and 10,244 (19.0%) deaths occurred, respectively. The optimal cut-off point of BMI at diagnosis was identified at 20.2 kg/m2 (log-rank statistic = 96.69, Q-statistic = 3.07, P< 0.01) for differentiating between the poorer and better OS in development cohort. When compared to the patients with BMI < 20.2 kg/m2, the patients with BMI ≥20.2 kg/m2 were significantly associated with the better OS in the Cox proportional hazard regression analysis (HR = 0.62, 95% CI = 0.54-0.72, P= 1.1×10-10). The association was validated in the nation-wide cohort showing the better OS in the patients with BMI ≥20.2 kg/m2. (HR = 0.64, 95% CI = 0.60-0.67, P< 0.01). Conclusions: We suggest the use of a BMI value of 20.2 kg/m2 to predict survival in Asian colorectal cancer patients.

Association of Long-term Use of Low-Dose Aspirin as Chemoprevention With Risk of Lung Cancer

Low-dose aspirin use for chemoprevention of lung cancer risk remains controversial. To investigate the association between low-dose aspirin use and lung cancer risk, and to identify specific subgroups that may derive the most benefit from low-dose aspirin use. This nationwide, retrospective, cohort study used data from the Korean National Health Information Database from 2002 to 2015. Data analyses were performed from October 2016 to December 2018. Eligible participants (n = 12 969 400) were people aged 40 to 84 years who had undergone national health screening between 2009 and 2010 and had no history of lung cancer between 2006 and 2010 and no standard-dose aspirin use for 6 months between 2002 and 2010. The duration of low-dose aspirin use between January 2002 and December 2010 was calculated for each participant. Lung cancer was defined as the first recorded diagnosis of lung cancer-using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes and expanding benefit coverage-between January 2011 and December 2015. A total of 63 040 participants with a mean (SD) age of 66.4 (9.3) years received a diagnosis of lung cancer. Of these, 45 156 (71.6%) were men. The incidence rate of lung cancer was 98.8 per 100 000 person-years. The duration of low-dose aspirin use was none for 10 987 417 participants (84.7%), 1 to 2 years for 750 992 participants (5.8%), 3 to 4 years for 506 945 participants (3.9%), 5 to 6 years for 371 062 participants (2.9%), 7 to 8 years for 240 528 participants (1.9%), and 9 years for 112 456 participants (0.9%). Compared with no aspirin use, 5 to 6 years (adjusted hazard ratio, 0.96 [95% CI, 0.92-0.99]), 7 to 8 years (adjusted hazard ratio, 0.94 [95% CI, 0.90-0.99]), and 9 years (adjusted hazard ratio, 0.89 [95% CI, 0.84-0.94]) of aspirin use were significantly associated with reduced lung cancer risk. After stratified analysis, a significant reduction of lung cancer risk was observed among people aged 65 years or older and among people without diabetes. Although the use of low-dose aspirin for more than 5 years was associated with decreased risk of lung cancer, particularly among elderly participants and among people without diabetes, the observed effect size was quite modest. Future prospective studies are needed to determine whether there is a causal association.

Association Between Changes in Hemoglobin Concentration and Cardiovascular Risks and All-Cause Mortality Among Young Women.

BackgroundAnemia is considered to increase the risk of mortality in high‐risk populations, but its effect has not been examined among young populations. This study aimed to determine the effect of hemoglobin (Hb) concentration and its changes on the risk of acute myocardial infarction (AMI), stroke, cerebrovascular disease and all‐cause mortality among young women.Methods and ResultsWe analyzed data from the Korean National Health Information Database on 808 143 women aged 20 to 39 years without any cardiocerebrovascular disease. A 1‐time Hb concentration and changes in Hb over a 2‐year period were calculated as exposures. Participants were followed for a median of 10 years to determine the risk of AMI, stroke, cerebrovascular disease, and all‐cause mortality. There were U‐ or J‐shaped associations between Hb concentration or change in Hb and AMI, stroke, cerebrovascular disease, and all‐cause mortality. Increasing the Hb concentration from normal to high increased the risk for AMI (hazard ratio [95% confidence interval]: 1.49 [1.08‐2.04]). With regard to the risk for stroke, increasing the Hb concentration from a normal to a high range increased the risk (hazard ratio [95% confidence interval]: 1.10 [1.02‐1.35]), and decreasing the Hb concentration from a high to a normal range decreased this risk (hazard ratio [95% confidence interval]: 0.80 [0.60‐0.97]). Improving anemia to the normal Hb range decreased all‐cause mortality (hazard ratio [95% confidence interval]: 0.81 [0.69‐0.94]); however, overcorrection of Hb concentration (Hb≥14.0 g/dL) was not significant.ConclusionsThese findings suggest that regular Hb analysis may assist in identifying young women who are at risk of AMI, stroke, cerebrovascular disease, and all‐cause mortality.