Accuracy of International Classification of Diseases-10 Codes for Cirrhosis and Portal Hypertensive Complications

BACKGROUND AND AIMS

International Classification of Diseases (ICD)-10 codes may correspond to cirrhosis diagnosis. However, these codes have not been as well studied as ICD-9 codes. We aimed to evaluate the positive predictive value (PPV) and specificity of ICD-10 codes for cirrhosis.

METHODS

We conducted a single-center retrospective study of patients in Michigan Medicine (Ann Arbor, MI, USA). We evaluated patients with at least one of 28 ICD-10 codes for cirrhosis and randomly selected controls for the presence of cirrhosis and/or portal hypertensive complications.

RESULTS

Among 1317 patients with at least one ICD-10 code consistent with cirrhosis and/or portal hypertension, 796 had confirmed cirrhosis. After excluding ICD-10 codes found in < 10 patients, we evaluated the PPV of the 19 remaining codes. Of these, 15 had a high PPV for cirrhosis (> 80%), including codes for cirrhosis itself, gastroesophageal varices, hepatic encephalopathy, and other portal hypertensive complications. Specificity of ICD codes for cirrhosis for these 15 codes was high (> 94% for all). PPV and specificity were high across liver disease etiologies. Among patients without portal hypertension, PPVs of ICD-10 codes for cirrhosis were lower but still > 80% for the most common codes. PPVs of most codes for portal hypertensive complications were > 70%. Defining cirrhosis based on the presence of any of the 15 codes resulted in a PPV of 86% and by two different codes, a PPV 94%.

CONCLUSIONS

ICD-10 codes for cirrhosis can accurately identify patients with cirrhosis with or without portal hypertensive complications.

Hepatic decompensation is accelerated in patients with cirrhosis and alpha-1 antitrypsin Pi∗MZ genotype

Background & Aims

Alpha-1 antitrypsin deficiency is caused by mutations in SERPINA1, most commonly homozygosity for the Pi∗Z variant, and can present as liver disease. While heterozygosity for Pi∗Z (Pi∗MZ) is linked to increased risk of cirrhosis, whether the Pi∗MZ genotype is associated with an increased rate of decompensation among patients who already have compensated cirrhosis is not known.

Methods

This was a retrospective study of Michigan Genomics Initiative participants with baseline compensated cirrhosis. The primary predictors were Pi∗MZ or Pi∗MS genotype (vs. Pi∗MM). The primary outcomes were hepatic decompensation with ascites, hepatic encephalopathy, or variceal bleeding, or the combined endpoint of liver-related death or liver transplant, both modeled with Fine-Gray competing risk models.

Results

We included 576 patients with baseline compensated cirrhosis who had undergone genotyping, of whom 474 had Pi∗MM, 49 had Pi∗MZ, and 52 had Pi∗MS genotypes. Compared to Pi∗MM genotype, Pi∗MZ was associated with increased rates of hepatic decompensation (hazard ratio 1.81; 95% CI 1.22-2.69; p = 0.003) and liver transplant or liver-related death (hazard ratio 2.07; 95% CI 1.21-3.52; p = 0.078). These associations remained significant after adjustment for severity of underlying liver disease, and were robust across subgroup analyses based on etiology, sex, obesity, and diabetes status. Pi∗MS was not associated with decompensation or death/transplantation.

Conclusions

The SERPINA1 Pi∗MZ genotype is associated with an increased rate of hepatic decompensation and decreased transplant-free survival among patients with baseline compensated cirrhosis.

Lay summary

There is a mutation in the gene SERPINA1 called Pi∗MZ which increases risk of liver scarring (cirrhosis); however, it is not known what effect Pi∗MZ has if someone already has cirrhosis. In this study, we found that people who had cirrhosis and Pi∗MZ developed complications from cirrhosis faster than those who did not have the mutation.