<p>Validity of Claims Diagnosis Codes for Cardiovascular Diseases in Diabetes Patients in Japanese Administrative Database</p>

Abstract

Background: Observational studies using large claims databases for diabetes patients have been increasingly conducted. While validation of outcomes is important in such studies, validation studies from Japan are still scarce and small in scale with questions remaining on the representativeness of their findings. We examined the positive predictive value (PPV) of outcomes that often develop in type 2 diabetes patients: cardiovascular outcomes including congestive heart failure (CHF), myocardial infarction (MI), stroke-related diseases, and renal outcomes including end stage renal disease (ESRD), and death using a large Japanese database containing administrative claims and electronic medical record (EMR) data. Patients and Methods: We used patient-level administrative claims data from 2003 and EMR data from 1985 to the most recent data up to December 2018 provided by Real World Data Co., Ltd. The database consisted of data from over 200 hospitals including ≥12 million uniquely identifiable patients. Among patients who had ≥1 type 2 diabetes diagnosis in the EMR, those who had administrative claims for each outcome were identified, and then the PPV was calculated for each outcome using the EMR as the gold standard. Results: The numbers of patients identified for each outcome were 1,700 for MI, 2,027 for hemorrhagic stroke, 3,722 for ESRD, 4,723 for ischemic stroke, 5,404 for CHF, 6,678 for any type of stroke, and 10,815 for death. PPVs ranged from 67.4% for ESRD, 78.7% for MI, 80.3% for death, 85.7% for ischemic stroke, 88.9% for any type of stroke, 89.9% for hemorrhagic stroke, and 95.7% for CHF. A post hoc analysis showed PPV for ESRD as 83.8%. Conclusion: This large-scale validation study on diagnosis in administrative claims showed reasonable PPVs for the outcomes. We believe that the definitions of outcomes can be considered to be appropriate for future studies using Japanese administrative claims data.

Accuracy of Japanese claims data in identifying diabetes‐related complications

“…The ICD‐10 based definition (definition 5) showed lower PPVs than those using DPC or ICD‐10 with medication. Ono et al reported that the PPV for congestive heart failure using ICD‐10 codes was 95% 46 . The discrepancy between that study and our findings was thought to be due to the study design.…”

“…In Japan, ICD‐10 codes were mainly given for examinations and/or medication as well as an actual diagnosis, so that those ICD‐10 codes (E10, E11 or E14 [either the 4 or 5 class of diabetic nephropathy] N18.4, N18.5, N18.9) were not given in clinical practice. This finding is consistent with a previous study 30,46 Gram and Vlasschaert et al showed large variations in accuracy regarding chronic kidney disease in a systematic review 33,48 . In our study, confirmation of continuous dialysis procedure codes is useful to exclude patients who underwent dialysis for acute kidney injury and subsequently withdrew from dialysis.…”

“…In Japan, some validation studies using actual chart review had relatively small sample sizes due to random sampling 42‐45 . Also, a recent study compared the administrative claims‐based definitions with electronic medical records in Japan, but in that study the gold standard was not based on actual chart reviews 46 . Although the sample size of the present study was relatively large, the sample size for each outcome was too small to establish a useful claims‐based definition for each diabetes‐related complication.…”

Hypertriglyceridemia Is an Independent Risk Factor for Cardiovascular Diseases in Korean Adults Aged 30–49 Years: a Nationwide Population-Based Study

“…The major limitation of the current study is that the events during the following period were assessed using claims data. Even though the sensitivity and positive predictive values of claims data with identical definitions for CVD to those used in the current study were reported to be as high as 90% in a previous validation study in Korea, 31 the findings might have been affected both by underestimation of the real incidence of CVD, especially for ischemic stroke, 32 and overestimation due to the low sensitivity of claims-based definitions. 31 33 In addition, clinical data during the follow-up period were not considered.…”

Cardiovascular and renal effectiveness of empagliflozin in routine care in East Asia: Results from the EMPRISE East Asia study

“…In Japan, HHF‐specific was defined as an inpatient HF diagnosis that either required the most healthcare resources, triggered hospitalization or was coded as the main disease on the hospital claim 14 . HHF‐broad was defined as any inpatient visit with an associated HF diagnosis code.…”