Evaluating Linkage Quality of Population-Based Administrative Data for Health Service Research

Background@#To overcome the limitations of relying on data from a single institution, many researchers have studied data linkage methodologies. Data linkage includes errors owing to legal issues surrounding personal information and technical issues related to data processing. Linkage errors affect selection bias, and external and internal validity. Therefore, quality verification for each connection method with adherence to personal information protection is an important issue. This study evaluated the linkage quality of linked data and analyzed the potential bias resulting from linkage errors. @*Methods@#This study analyzed claims data submitted to the Health Insurance Review and Assessment Service (HIRA DATA). The linkage errors of the two deterministic linkage methods were evaluated based on the use of the match key. The first deterministic linkage uses a unique identification number, and the second deterministic linkage uses the name, gender, and date of birth as a set of partial identifiers. The linkage error included in this deterministic linkage method was compared with the absolute standardized difference (ASD) of Cohen’s according to the baseline characteristics, and the linkage quality was evaluated through the following indicators: linked rate, false match rate, missed match rate, positive predictive value, sensitivity, specificity, and F1-score. @*Results@#For the deterministic linkage method that used the name, gender, and date of birth as a set of partial identifiers, the true match rate was 83.5 and the missed match rate was 16.5.Although there was bias in some characteristics of the data, most of the ASD values were less than 0.1, with no case greater than 0.5. Therefore, it is difficult to determine whether linked data constructed with deterministic linkages have substantial differences. @*Conclusion@#This study confirms the possibility of building health and medical data at the national level as the first data linkage quality verification study using big data from the HIRA. Analyzing the quality of linkages is crucial for comprehending linkage errors and generating reliable analytical outcomes. Linkers should increase the reliability of linked data by providing linkage error-related information to researchers. The results of this study will serve as reference data to increase the reliability of multicenter data linkage studies.

COVID-19 International Collaborative Research by the Health Insurance Review and Assessment Service Using Its Nationwide Real-world Data: Database, Outcomes, and Implications / 예방의학회지

This article aims to introduce the inception and operation of the COVID-19 International Collaborative Research Project, the world’s first coronavirus disease 2019 (COVID-19) open data project for research, along with its dataset and research method, and to discuss relevant considerations for collaborative research using nationwide real-world data (RWD). COVID-19 has spread across the world since early 2020, becoming a serious global health threat to life, safety, and social and economic activities. However, insufficient RWD from patients was available to help clinicians efficiently diagnose and treat patients with COVID-19, or to provide necessary information to the government for policy-making. Countries that saw a rapid surge of infections had to focus on leveraging medical professionals to treat patients, and the circumstances made it even more difficult to promptly use COVID-19 RWD. Against this backdrop, the Health Insurance Review and Assessment Service (HIRA) of Korea decided to open its COVID-19 RWD collected through Korea’s universal health insurance program, under the title of the COVID-19 International Collaborative Research Project. The dataset, consisting of 476 508 claim statements from 234 427 patients (7590 confirmed cases) and 18 691 318 claim statements of the same patients for the previous 3 years, was established and hosted on HIRA’s in-house server. Researchers who applied to participate in the project uploaded analysis code on the platform prepared by HIRA, and HIRA conducted the analysis and provided outcome values. As of November 2020, analyses have been completed for 129 research projects, which have been published or are in the process of being published in prestigious journals.

Impact of the Dedicated Neurointensivists on the Outcome in Patients with Ischemic Stroke Based on the Linked Big Data for Stroke in Korea

Background@#Neurocritical care by dedicated neurointensivists may improve outcomes of critically ill patients with severe brain injury. In this study, we aimed to validate whether neurointensive care could improve the outcome in patients with critically ill acute ischemic stroke using the linked big dataset on stroke in Korea. @*Methods@#We included 1,405 acute ischemic stroke patients with mechanical ventilator support in the intensive care unit after an index stroke. Patients were retrieved from linking the Clinical Research Center for Stroke Registry and the Health Insurance Review and Assessment Service data from the period between January 2007 and December 2014. The outcomes were mortality at discharge and at 3 months after an index stroke. The main outcomes were compared between the centers with and without dedicated neurointensivists. @*Results@#Among the included patients, 303 (21.6%) were admitted to the centers with dedicated neurointensivists. The patients treated by dedicated neurointensivists had significantly lower in-hospital mortality (18.3% vs. 26.8%, P = 0.002) as well as lower mortality at 3-month (38.0% vs. 49.1%, P < 0.001) than those who were treated without neurointensivists. After adjusting for confounders, a treatment without neurointensivists was independently associated with higher in-hospital mortality (odds ratio [OR], 1.59; 95% confidence intervals [CIs], 1.13–2.25; P = 0.008) and 3-month mortality (OR, 1.48; 95% CIs, 1.12–1.95; P = 0.005). @*Conclusion@#Treatment by dedicated neurointensivists is associated with lower in-hospital and 3-month mortality using the linked big datasets for stroke in Korea. This finding stresses the importance of neurointensivists in treating patients with severe ischemic stroke.

Complications Following Colonoscopy in a Nationwide Standard Cohort: A Retrospective Case-control Study / 대한소화기학회지

BACKGROUND/AIMS: Despite the many reports of colonoscopy complications worldwide, few studies have been performed at the population level in Korea. In this study, a population-based study was performed to evaluate the incidence of post-colonoscopy perforations compared to a control group. METHODS: Between January 2011 and December 2011, data for all cases (age over 45) who underwent a colonoscopy were collected from National Health Insurance Service using a random sampling method. The clinical characteristics and perforation incidence (within 30 days after the colonoscopy) of cases were identified, and cases were then compared with controls who had not undergone a colonoscopy. RESULTS: Among 1,380,000 subjects, 31,177 cases and 62,354 controls were identified. Perforation occurred in 14 patients (0.04%) in the case group and one patient (<0.01%) in the control group (RR, 28.0; 95% CI 3.7–212.9, p<0.001). Subgroup analysis was followed according to the endoscopic procedure, gender and age. In subgroup analysis, colonoscopy-associated perforations occurred more in the therapeutic procedure (RR, 26; 95% CI 1.46–461.46), male (RR, 50; 95% CI 2.96–844.41), and age of 45–60 years (RR, 30; 95% CI 1.71–525.23). CONCLUSIONS: A colonoscopy procedure is related to an increased risk of perforation at the population level. In addition, the therapeutic procedure, male, and age of 45-60 years appeared to be associated with an increased risk of perforation.

Building Linked Big Data for Stroke in Korea: Linkage of Stroke Registry and National Health Insurance Claims Data

BACKGROUND: Linkage of public healthcare data is useful in stroke research because patients may visit different sectors of the health system before, during, and after stroke. Therefore, we aimed to establish high-quality big data on stroke in Korea by linking acute stroke registry and national health claim databases. METHODS: Acute stroke patients (n = 65,311) with claim data suitable for linkage were included in the Clinical Research Center for Stroke (CRCS) registry during 2006–2014. We linked the CRCS registry with national health claim databases in the Health Insurance Review and Assessment Service (HIRA). Linkage was performed using 6 common variables: birth date, gender, provider identification, receiving year and number, and statement serial number in the benefit claim statement. For matched records, linkage accuracy was evaluated using differences between hospital visiting date in the CRCS registry and the commencement date for health insurance care in HIRA. RESULTS: Of 65,311 CRCS cases, 64,634 were matched to HIRA cases (match rate, 99.0%). The proportion of true matches was 94.4% (n = 61,017) in the matched data. Among true matches (mean age 66.4 years; men 58.4%), the median National Institutes of Health Stroke Scale score was 3 (interquartile range 1–7). When comparing baseline characteristics between true matches and false matches, no substantial difference was observed for any variable. CONCLUSION: We could establish big data on stroke by linking CRCS registry and HIRA records, using claims data without personal identifiers. We plan to conduct national stroke research and improve stroke care using the linked big database.

Primary peritoneal serous papillary carcinoma presenting as a large mesenteric mass mistaken for ovarian cancer: a case of primary peritoneal carcinoma

Peritoneal origin serous papillary carcinoma is an uncommon primary malignancy occurring in the abdominal or pelvic peritoneum lining. It is characterized by peritoneal carcinomatosis with massive ascites, uninvolved or minimally involved ovary, and is histologically indistinguishable from ovarian serous tumors. Better recognition of this phenomenon in recent years has contributed to an increasing diagnostic frequency. We describe a rare case of peritoneal origin serous papillary carcinoma with unusual clinical presentations involving a solitary primary tumor originating from the peritoneal lining of the sigmoid colonal mesentery, without pelvic lymph node involvement or distant metastasis. Because of the location and morphological similarity, it was misdiagnosed as an ovarian malignancy. We aim to assist in the diagnosis of this disease with the following case report, thereby improving the management of patients with this condition.

Postnatal development of the auditory brainstem response in theguinea pig / 대한이비인후과학회지

No abstract available.