Whether the incidence of autoimmune hepatitis (AIH) is higher in women prescribed antibiotics during pregnancy remains to be determined. Administrative databases and hospital abstracts were reviewed to identify all pregnant women in the province of Manitoba from 1996 to 2001 who were prescribed antibiotics during pregnancy and subsequently diagnosed with AIH until 2020. In this study, 70,666 pregnant women were identified during the 5-year period. Antibiotics were prescribed in 11,654 (16.5%). AIH was subsequently diagnosed in more mothers who were prescribed antibiotics than in those who were not (82/11,654 [0.7%] versus 166/58,975 [0.28%], p <0.0001). The number of antibiotic prescriptions was higher in mothers who subsequently developed AIH than in those who were prescribed antibiotics but did not develop AIH (0.56 [SD 1.09] versus 0.24 [SD 0.67], p <0.0001) as were the prescribed durations of treatment (4.19 [SD 7.72] versus 2.03 [SD 7.55] days, p <0.0001). The mean ages (25.9 [SD 6.0] and 26.8 [SD 5.8]; years) and times to AIH diagnosis (10.6 [SD 4.9] and 10.8 [SD 4.8] years) were similar in mothers who were prescribed and not prescribed antibiotics and developed AIH. The relative risk of developing AIH in antibiotic recipients was 2.5 (95% CI 1.92-3.25, p <0.0001), and the hazard ratio was 2.58 (95% CI 1.98-3.36, p <0.001). These results describe an association between mothers prescribed antibiotics during pregnancy and the subsequent development of AIH.

Understanding the impact of wider access to treatment on chronic hepatitis C (CHC) prevalence and the undiagnosed CHC proportion is important to achieving the World Health Organization's 2030 elimination targets. This research aimed to: (1) estimate the CHC prevalence and undiagnosed rates in Alberta, Canada; and (2) explore the impact of new direct-acting antiviral therapy on these rates since its introduction in 2014. This study adopted a two-step approach to estimate CHC prevalence and undiagnosed rates. This involved a population-based retrospective analysis of health administrative data for Alberta from 2002 to 2018 to generate CHC-related events for three birth cohorts: individuals born before 1945, individuals born between 1945 and 1965, and individuals born after 1965. A back-calculation method was employed to obtain historical prevalence and incidence estimates. After the introduction of direct-acting antiviral treatment in 2014, the mean prevalence of CHC over all the birth cohorts fell by approximately 6.5% from 1.23% (95% CI: 0.97%-1.5%) to 1.15% (95% CI: 0.91%-1.45%) between 2015 and 2018. Similar trends were estimated for the 1945-1965 and the >1965 birth cohorts over the same period. Likewise, the mean proportion of undiagnosed CHC infections over all the birth cohorts fell by approximately 8.25% from 39.36% (95% CI: 30.08%-48.48%) to 36.36% (95% CI: 27.49%-45.31%) over the same period. A similar trend was experienced in all three birth cohorts. This is the first study to estimate CHC prevalence and undiagnosed proportions in Alberta using provincial health administrative data. These results could provide vital evidence to guide decisions about current and future hepatitis C virus strategies and help achieve the World Health Organization goal of eliminating hepatitis C in Canada by 2030.

American Association for the Study of Liver Diseases practice guidance on metabolic dysfunction-associated steatotic liver disease (MASLD) has recommended using specific cut-off values for the Fibrosis-4 index (FIB-4) to detect cirrhosis. A cut-off of 3.48 is recommended for identifying stage 4 fibrosis (F4) with high specificity, while a cut-off of 1.67 is suggested for ruling out advanced fibrosis. Our study aimed to validate the diagnostic performance of these new FIB-4 cut-offs in our cohort of biopsy-proven MASLD from two Canadian tertiary care centres. Our study included 390 patients with biopsy-proven MASLD with F4 prevalence of 22%. Among the 87 patients with cirrhosis, 37 (42.5%) were correctly identified with a FIB-4 ≥3.48. FIB-4 had an area under the receiver operating characteristic curve of 0.79 at the proposed cut-off points, with 32% of patients being indeterminate or misclassified. Sensitivity and positive-predictive value for the FIB-4 cut-off were 65% and 68.5%, respectively, while the specificity and negative-predictive value were 93% and 92%, respectively. In conclusion, in our biopsy-proven MASLD cohort, recommended FIB-4 cut-offs ≥3.48 and <1.67 had low sensitivity but high specificity. An upper FIB-4 cut-off of 3.48 would have missed nearly one in four cirrhosis cases. The proposed FIB-4 thresholds for identifying F4 in MASLD patients have limited diagnostic utility in higher prevalence tertiary hepatology cohorts.

Case ascertainment algorithms were developed and validated to identify people living with cirrhosis in administrative health data in Manitoba, Canada using primary care electronic medical records (EMR) to define the reference standards. We linked provincial administrative health data to primary care EMR data. The validation cohort included 116,675 Manitobans aged >18 years with at least one primary care visit between April 1998 and March 2015. Hospital records, physician billing claims, vital statistics, and prescription drug data were used to develop and test 93 case-finding algorithms. A validated case definition for primary care EMR data was the reference standard. We estimated sensitivity, specificity, positive and negative predictive values (PPV, NPV), Youden's index, area under the receiver operative curve, and their 95% confidence intervals (CIs). A total of 116,675 people were in the validation cohort. The prevalence of cirrhosis was 1.4% (n = 1593). Algorithm sensitivity estimates ranged from 32.5% (95% CI 32.2-32.8) to 68.3% (95% CI 68.0-68.9) and PPV from 17.4% (95% CI 17.1-17.6) to 23.4% (95% CI 23.1-23.6). Specificity (95.5-98.2) and NPV (approximately 99%) were high for all algorithms. The algorithms had slightly higher sensitivity estimates among men compared with women, and individuals aged ≥45 years compared to those aged 18-44 years. Cirrhosis algorithms applied to administrative health data had moderate validity when a validated case definition for primary care EMRs was the reference standard. This study provides algorithms for identifying diagnosed cirrhosis cases for population-based research and surveillance studies.

The Canadian Network on Hepatitis C Blueprint Writing Committee and Working Groups. Blueprint to inform hepatitis C elimination efforts in Canada. Montreal, QC: Available at: canhepc.ca/sites/default/ files/media/documents/blueprint_hcv_2019_05.pdf (accessed [date]). This publication is available in English and French on the Canadian Network on Hepatitis C (CanHepC)'s website at: www.canhepc.ca/en/blueprint/publication. Visit the website for the most up-to-date version of this publication and for more information on the CanHepC network.

To develop and validate case definitions to identify patients with cirrhosis and alcohol-related cirrhosis using primary care electronic medical records (EMRs) and to estimate cirrhosis prevalence and incidence in pan-Canadian primary care databases, between 2011 and 2019. A total of 689,301 adult patients were included with ≥1 visit to a primary care provider within the Canadian Primary Care Sentinel Study Network between January 1, 2017, and December 31, 2018. A subsample of 17,440 patients was used to validate the case definitions. Sensitivity, specificity, predictive values were calculated with their 95% CIs and then determined the population-level prevalence and incidence trends with the most accurate case definition. The most accurate case definition included: ≥1 health condition, billing, or encounter diagnosis for International Classification of Diseases, Ninth Revision codes 571.2, 571.5, 789.59, or 571. Sensitivity (84.6; 95% CI 83.1%-86.%), specificity (99.3; 95% CI 99.1%-99.4%), positive predictive values (94.8; 95% CI 93.9%-95.7%), and negative predictive values (97.5; 95% CI 97.3%-97.7%). Application of this definition to the overall population resulted in a crude prevalence estimate of (0.46%; 95% CI 0.45%-0.48%). Annual incidence of patients with a clinical diagnosis of cirrhosis nearly doubled between 2011 (0.05%; 95% CI 0.04%-0.06%) and 2019 to (0.09%; 95% CI 0.08%-0.09%). The EMR-based case definition accurately captured patients diagnosed with cirrhosis in primary care. Future work to characterize patients with cirrhosis and their primary care experiences can support improvements in identification and management in primary care settings.

Metabolic syndrome (MetS) is considered an important risk factor for non-alcoholic fatty liver disease (NAFLD). The aim of this study was to measure the prevalence of MetS based on six different MetS definitions and compare the performance of various definitions for identifying diabetes, hypertension, and dyslipidemia among NAFLD patients. The definitions compared were those developed by the World Health Organization (WHO), National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III), International Diabetes Federation (IDF), American Association of Clinical Endocrinologists (AACE), American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI), and Interim Joint Statement "harmonized" criteria. Receiver operator characteristic (ROC) curves were plotted for the six MetS definitions with NAFLD diagnosis. The diagnosis for NAFLD was established based on liver imaging or biopsy compatible with fatty liver disease. A total of 500 NAFLD patients were analyzed. The mean age was 61.2 (SD 13.2) years, and BMI was 32.7 (SD 8.0) kg/m2. The most prevalent MetS component was dyslipidemia (83%), followed by hypertension (60%), obesity (61%), and diabetes (57%). The prevalence of MetS according to the WHO, NCEP/ATP-III, IDF, AACE, AHA/NHLBI, and harmonized criteria was 69%, 59%, 54%, 64%, 78%, and 79%, respectively. The highest area under the ROC curve for diabetes and hypertension was with the WHO definition (0.7405) and (0.8120), respectively. The prevalence of MetS in NAFLD patients varies according to the definitions of MetS employed. The modified WHO definition appeared to be most useful for the screening of MetS in NAFLD patients.