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

Area of Science:

• Hepatology
• Epidemiology
• Health Informatics

Background:

• Administrative data, including ICD-9-CM codes, are used for hepatitis B or C virus (HBV, HCV) research.
• Validation of ICD-9-CM codes for identifying cirrhotic patients with HBV or HCV outside the Veterans Health Administration is lacking.
• Accurate identification of patient cohorts is crucial for epidemiological and cost-effectiveness studies.

Purpose of the Study:

• To validate the positive predictive value (PPV) of ICD-9-CM codes for identifying cirrhotic patients with chronic hepatitis B or C virus (HBV, HCV).
• To assess the reliability of ICD-9-CM coding algorithms in a large healthcare system for epidemiological research.

Main Methods:

• Evaluation of the PPV of ICD-9-CM codes in a diverse healthcare system (University of Pennsylvania Health System).
• Review of a random sample of 200 cirrhotic patients with HCV codes and 150 with HBV codes.
• Analysis of variations in coding algorithms using inpatient and outpatient data.

Main Results:

• The PPV for identifying HCV among cirrhotic patients was 88.0% (using 1 inpatient or 2 outpatient codes).
• The PPV for identifying HBV among cirrhotic patients was 81.3% (using 1 inpatient or 2 outpatient codes).
• Different combinations of ICD-9-CM codes were evaluated to optimize PPV.

Conclusions:

• ICD-9-CM codes demonstrate a high PPV for identifying chronic HBV and HCV in cirrhotic patients.
• Validated ICD-9-CM codes are suitable for future epidemiologic studies on disease burden.
• These codes can aid in the proper allocation of healthcare resources for HBV and HCV management.