Coding algorithms for identifying patients with cirrhosis and hepatitis B or C virus using administrative data

Abstract

Background & Aims Despite the use of administrative data to perform epidemiological and cost-effectiveness research on patients with hepatitis B or C virus (HBV, HCV), there are no data outside of the Veterans Health Administration validating whether International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes can accurately identify cirrhotic patients with HBV or HCV. The validation of such algorithms is necessary for future epidemiological studies. Methods We evaluated the positive predictive value (PPV) of ICD-9-CM codes for identifying chronic HBV or HCV among cirrhotic patients within the University of Pennsylvania Health System, a large network that includes a tertiary care referral center, a community-based hospital, and multiple outpatient practices across southeastern Pennsylvania and southern New Jersey. We reviewed a random sample of 200 cirrhotic patients with ICD-9-CM codes for HCV and 150 cirrhotic patients with ICD-9-CM codes for HBV. Results The PPV of 1 inpatient or 2 outpatient HCV codes was 88.0% (168/191, 95% CI: 82.5–92.2%), while the PPV of 1 inpatient or 2 outpatient HBV codes was 81.3% (113/139, 95% CI: 73.8–87.4%). Several variations of the primary coding algorithm were evaluated to determine if different combinations of inpatient and/or outpatient ICD-9-CM codes could increase the PPV of the coding algorithm. Conclusions ICD-9-CM codes can identify chronic HBV or HCV in cirrhotic patients with a high PPV, and can be used in future epidemiologic studies to examine disease burden and the proper allocation of resources.

Impact of All‐Oral Direct‐Acting Antivirals on Clinical and Economic Outcomes in Patients With Chronic Hepatitis C in the United States

“…However, a recent validation study reported that a coding algorithm including 1 inpatient or 2 outpatients ICD-9 codes for HCV and cirrhosis had high accuracy, although using ICD-10 codes has not yet been validated. (37) Previous studies also validated that the use of billing ICD-9 codes for the diagnosis of DCC and HCC had positive predictive value of 88%-91%. (20) It is possible that incomplete, missing, or miscoded claims may impact the study findings; however, coding errors are likely distributed evenly between the treated and untreated groups.…”

“…The Truven claims databases contain deidentified patient‐level health data, where individual records cannot be linked back to an original health record system and/or other databases for ICD code validations. However, a recent validation study reported that a coding algorithm including 1 inpatient or 2 outpatients ICD‐9 codes for HCV and cirrhosis had high accuracy, although using ICD‐10 codes has not yet been validated . Previous studies also validated that the use of billing ICD‐9 codes for the diagnosis of DCC and HCC had positive predictive value of 88%‐91% .…”

Validation of a hierarchical algorithm to define chronic liver disease and cirrhosis etiology in administrative healthcare data

“…To date, there have been a small number of studies that have validated several CLD and cirrhosis etiologies within administrative healthcare data. [6][7][8][9][10] However, to our knowledge no previous work has evaluated a hierarchical algorithm to define etiology in a defined population with CLD or cirrhosis similar to how etiology is defined in clinical practice.…”

Impact of hepatitis C virus treatment on the risk of non‐hepatic cancers among hepatitis C virus‐infected patients in the US

“…These diagnoses have been shown to be highly, with a positive predictive value of 88% (95% confidence interval (CI): 82.5%-92.2%) for identifying HCV infection. 24 We considered the initial HCV diagnosis date as the index date. We included patients who met the following criteria:…”