ABSTRACT
BACKGROUND: Large-scale epidemiological studies of primary biliary cirrhosis (PBC) have been hindered by difficulties in case ascertainment. OBJECTIVE: To develop coding algorithms for identifying PBC patients using administrative data--a widely available data source. METHODS: Population-based administrative databases were used to identify patients with a diagnosis code for PBC from 1994 to 2002. Coding algorithms for confirmed PBC (two or more of antimitochondrial antibody positivity, cholestatic liver biochemistry and/or compatible liver histology) were derived using chart abstraction data as the reference. Patients with a recorded PBC diagnosis but insufficient confirmatory data were classified as 'suspected PBC'. RESULTS: Of 189 potential PBC cases, 119 (60%) had confirmed PBC and 28 (14%) had suspected PBC. The optimal algorithm including two or more uses of a PBC code had a sensitivity of 94% (95% CI 71% to 100%) and positive predictive values of 73% (95% CI 61% to 75%) for confirmed PBC, and 89% (95% CI 82% to 94%) for confirmed or suspected PBC. Sensitivity analyses revealed greater accuracy among women, and with the use of multiple data sources and one or more years of data. Inclusion of diagnosis codes for conditions frequently misclassified as PBC did not improve algorithm performance. CONCLUSIONS: Administrative databases can reliably identify patients with PBC and may facilitate epidemiological investigations of this condition.
Subject(s)
Algorithms , Epidemiologic Research Design , Liver Cirrhosis, Biliary/diagnosis , Adult , Aged , Aged, 80 and over , Databases, Factual , Epidemiologic Methods , Female , Forms and Records Control/methods , Humans , Liver Cirrhosis, Biliary/epidemiology , Male , Middle Aged , Predictive Value of Tests , Sensitivity and Specificity , Young AdultABSTRACT
BACKGROUND: The accurate diagnosis of hepatitis C virus (HCV)-related fibrosis is crucial for prognostication and treatment decisions. Due to the limitations of biopsy, noninvasive alternatives including FibroTest and FibroScan have been developed. Our objective was to systematically review studies describing the accuracy of these tests for predicting HCV-related fibrosis. METHODS: Studies comparing FibroTest or FibroScan versus biopsy in HCV patients were identified via an electronic search. Random effects meta-analyses and areas under summary receiver operating characteristics curves (AUC) were examined to characterize test accuracy for significant fibrosis (F2-4) and cirrhosis. Heterogeneity was explored using meta-regression. RESULTS: Twelve studies were identified, 9 for FibroTest (N = 1,679) and 4 for FibroScan (N = 546). In heterogeneous analyses for significant fibrosis, the AUCs for FibroTest and FibroScan were 0.81 (95% CI 0.78-84) and 0.83 (0.03-1.00), respectively. At a threshold of approximately 0.60, the sensitivity and specificity of the FibroTest were 47% (35-59%) and 90% (87-92%). For FibroScan (threshold approximately 8 kPa), corresponding values were 64% (50-76%) and 87% (80-91%), respectively. Methodological quality, the length of liver biopsy specimens, and inclusion of special populations did not explain the observed heterogeneity. However, the diagnostic accuracy of both measures was associated with the prevalence of significant fibrosis and cirrhosis in the study populations. For cirrhosis, the summary AUCs for FibroTest and FibroScan were 0.90 (95% CI not calculable) and 0.95 (0.87-0.99), respectively. CONCLUSIONS: FibroTest and FibroScan have excellent utility for the identification of HCV-related cirrhosis, but lesser accuracy for earlier stages. Refinements are necessary before these tests can replace liver biopsy.
