Context Tumor recurrence is a major issue for patients with hepatocellular carcinoma (HCC) following curative liver resection. Objective To investigate the association between nucleoside analogue use and risk of tumor recurrence in patients with hepatitis B virus (HBV)−related HCC after curative surgery. Design, Setting, and Participants A nationwide cohort study between October 2003 and September 2010. Data from the Taiwan National Health Insurance Research Database. Among 100 938 newly diagnosed HCC patients, we identified 4569 HBV-related HCC patients who received curative liver resection for HCC between October 2003 and September 2010. Main Outcome Measures The risk of first tumor recurrence was compared between patients not taking nucleoside analogues (untreated cohort, n = 4051) and patients taking nucleoside analogues (treated cohort, n = 518). Cumulative incidences and hazard ratios (HRs) were calculated after adjusting for competing mortality. Results The treated cohort had a higher prevalence of liver cirrhosis when compared with the untreated cohort (48.6% vs 38.7%; P  Conclusion Nucleoside analogue use was associated with a lower risk of HCC recurrence among patients with HBV-related HCC after liver resection.

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Association between nucleoside analogues and risk of hepatitis B virus-related hepatocellular carcinoma recurrence following liver resection

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.

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

Validation of acute myocardial infarction cases in the national health insurance research database in taiwan.

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

Objective 
To conduct a systematic review of studies reporting on the validity of International Classification of Diseases (ICD) codes for identifying stroke in administrative data.


Methods 
MEDLINE and EMBASE were searched (inception to February 2015) for studies: (a) Using administrative data to identify stroke; or (b) Evaluating the validity of stroke codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), or Kappa scores) for stroke, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2015) of original papers. Studies solely evaluating codes for transient ischaemic attack were excluded. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool.


Results 
Seventy-seven studies published from 1976–2015 were included. The sensitivity of ICD-9 430-438/ICD-10 I60-I69 for any cerebrovascular disease was ≥ 82% in most [≥ 50%] studies, and specificity and NPV were both ≥ 95%. The PPV of these codes for any cerebrovascular disease was ≥ 81% in most studies, while the PPV specifically for acute stroke was ≤ 68%. In at least 50% of studies, PPVs were ≥ 93% for subarachnoid haemorrhage (ICD-9 430/ICD-10 I60), 89% for intracerebral haemorrhage (ICD-9 431/ICD-10 I61), and 82% for ischaemic stroke (ICD-9 434/ICD-10 I63 or ICD-9 434&436). For in-hospital deaths, sensitivity was 55%. For cerebrovascular disease or acute stroke as a cause-of-death on death certificates, sensitivity was ≤ 71% in most studies while PPV was ≥ 87%.


Conclusions 
While most cases of prevalent cerebrovascular disease can be detected using 430-438/I60-I69 collectively, acute stroke must be defined using more specific codes. Most in-hospital deaths and death certificates with stroke as a cause-of-death correspond to true stroke deaths. Linking vital statistics and hospitalization data may improve the ascertainment of fatal stroke.

/pdf/validity-of-diagnostic-codes-for-acute-stroke-in-7y719hp2mz.pdf

Validity of Diagnostic Codes for Acute Stroke in Administrative Databases: A Systematic Review.

Objective
The National Health Insurance Research Database (NHIRD) is commonly used for pharmacoepidemiological research in Taiwan. This study evaluated the validity of the database for patients with a principal diagnosis of ischemic stroke.

Study design and methods
This cross-sectional study compares records in the NHIRD with those in one medical center. Patients hospitalized for ischemic stroke in 1999 were identified from both databases. The discharge notes, laboratory data, and medication orders during admission and the first discharge visit were reviewed to validate ischemic stroke diagnoses and aspirin prescribing in the NHIRD. Agreement between the two databases in comorbidities of ischemic stroke diagnosis was evaluated using ICD-9 codes.

Results
Three hundred and seventy two cases were identified from the NHIRD; among them, 364 cases (97.85%) were confirmed as ischemic stroke by radiology examination and clinical presentation. Among these confirmed cases, 344 (94.51%) were assigned ‘ischemic stroke’ as the principal diagnosis in the NHIRD. The overall agreement of comorbid diagnoses between the databases was 48.39%. The PPV for selected conditions also varied widely, from 0.50 for fracture to 1.00 for colon cancer. The accuracy of recorded aspirin prescriptions was higher in first post-discharge visits (PPV = 0.94) than during hospitalization (PPV = 0.88).

Conclusion
The accuracy of the NHIRD in recording ischemic stroke diagnoses and aspirin prescriptions was high, and the NHIRD appears to be a valid resource for population research in ischemic stroke. Copyright © 2010 John Wiley & Sons, Ltd.

Ming Liang Lai

Papers

Validation of the National Health Insurance Research Database with ischemic stroke cases in Taiwan.