Use of administrative claims data for identifying patients with cirrhosis

J Clin Gastroenterol. May-Jun 2013;47(5):e50-4. doi: 10.1097/MCG.0b013e3182688d2f.

Abstract

Background: Administrative data are used in clinical research, but the validity of ICD-9 codes to identify cirrhotic patients has not been well established.

Goals: To determine the diagnostic accuracy of ICD-9 codes for cirrhosis in clinical practice.

Study: We conducted a retrospective cohort study of patients from a safety-net hospital between 2008 and 2011. Patients were initially identified using ICD-9 codes for cirrhosis or a resultant complication. The gold-standard for diagnosis of cirrhosis was histology and/or imaging based on medical record review. Sensitivity, specificity, positive predictive values, and negative predictive values for each ICD-9 code were calculated. Diagnostic accuracy was assessed by the c-statistic using receiver operator characteristic curve analysis.

Results: We identified 2893 patients with an ICD-9 code for cirrhosis, of whom 50.2% had 1 ICD-9 code, 20.3% had 2 different codes, and 29.5% had 3 or more codes. Cirrhosis was confirmed in 44.0% of patients with 1 ICD-9 code, 82.6% with 2 codes, and 95.7% of those with at least 3 codes. Ascites had a significantly lower positive predictive values for cirrhosis than other ICD-9 codes (P<0.001). The optimal combination of ICD-9 codes to identify cirrhotic patients included all codes except that of ascites, with a c-statistic of 0.71 in our derivation cohort. The sensitivity of this combination was confirmed to be 98% in a validation cohort of 285 patients with known cirrhosis.

Conclusions: Administrative data can identify patients with cirrhosis with high accuracy, although ascites has a significantly lower positive predictive value than other ICD-9 codes.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Clinical Coding
  • Cohort Studies
  • Electronic Health Records*
  • Female
  • Humans
  • International Classification of Diseases*
  • Liver Cirrhosis / diagnosis*
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • ROC Curve
  • Retrospective Studies
  • Sensitivity and Specificity