NEW YORK (Reuters Health) - The prevalence of cirrhosis in patients with chronic hepatitis C infection may be as much as four times higher than previously estimated, according to a recent cohort study.
A high percentage of hepatitis C patients with biopsy-confirmed cirrhosis of the liver are not assigned the appropriate International Classification of Diseases, Ninth Revision (ICD-9) code and, therefore, in cohort studies the prevalence of cirrhosis is significantly underestimated, according to the authors of this new study online July 28 in the American Journal of Gastroenterology.
"Establishing the diagnosis of cirrhosis can be very complex and traditionally has required liver biopsy," lead author of the new cohort study, Dr. Stuart Gordon, a gastroenterologist at Henry Ford Health System in Detroit, Michigan, told Reuters Health by email. "However, a biomarker index derived from blood tests (liver function tests and platelet count) called FIB-4 (Firbrosis-4) may also provide good evidence that underlying cirrhosis exists."
Dr. Gordon and colleagues studied patients enrolled in the Chronic Hepatitis Cohort Study (CHeCS) who received health services between 2006 and 2010 to determine if they had cirrhosis based on liver biopsy reports, diagnosis and procedure codes for cirrhosis or hepatic decompensation, or FIB-4 scores.
Of the 9,783 patients included in the cohort, 2,788 (28.5%) were considered cirrhotic based on the study criteria. Only 661 (7%) patients had biopsy-confirmed cirrhosis, whereas FIB-4 scores identified 2,194 (22%) of the cirrhotic hepatitis C patients. Additionally, of the patients with biopsy-confirmed cirrhosis, only 356 (54%) had the appropriate ICD-9 code for cirrhosis documented in their medical record.
Multivariable logistic modeling revealed that older age, male gender, Asian race, Hispanic ethnicity, HCV genotype 3 infection, HIV coinfection, history of antiviral therapy, and alcohol abuse, were independently associated with higher odds of cirrhosis (p<0.05). On the contrary, private health insurance coverage, HCV genotype 2, and black race were associated with lower odds of cirrhosis.
"Our finding that 50% of patients with biopsy confirmed cirrhosis lacked an associated ICD-9 code for cirrhosis suggests that reliance upon ICD-9 coding data for analysis of current electronic health records may be unreliable," Dr. Gordon told Reuters Health.
The CDC Foundation, which receives grants from AbbVie, Gilead Sciences, and Janssen Pharmaceuticals, funds CHeCS. Dr. Gordon reported relationships with pharmaceutical companies including AbbVie and Gilead.
Am J Gastroenterol 2015.
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