Cigarette Smoking in Persons Living with Hepatitis C: The National Health and Nutrition Examination Survey (NHANES), 1999-2014

Hepatitis C and Cigarette Smoking Behavior: Themes From Focus Groups

INTRODUCTION

People with chronic hepatitis C virus (HCV; PWHC) use cigarettes at a much higher prevalence than other individuals, and smoking can exacerbate the harms specifically related to HCV (eg, hepatocellular carcinoma). Little is known about factors related to cigarette use among PWHC.

AIMS AND METHODS

This study examined focus group data to explore beliefs and behaviors related to cigarette use among PWHC. Qualitative data from two focus groups of PWHC reporting current cigarette smoking (n = 15, 60% male) were collected using a semi-structured interview guide. Participants were asked about reasons for smoking, barriers to quitting smoking, and the relationship of HCV to smoking. Focus groups were transcribed verbatim and coded in NVivo 12. Four coders examined themes that arose in the focus groups. Common themes are described and supported with quotes.

RESULTS

Reasons for smoking included addiction to cigarettes, stress, substituting cigarettes for other drugs, and social norms, while reasons for quitting included health and being free from the use of all drugs. Barriers to quitting included concerns about coping with stress, weight gain, and having a lack of support for and education about quitting. Many participants believed there was a link between smoking and HCV and discussed smoking in relation to the stress of an HCV diagnosis.

CONCLUSIONS

Participants identified both HCV-related and non-HCV-related aspects of cigarette smoking and cessation-related behaviors that could be targeted in cessation treatment. More research is needed to identify the best treatment approaches that reduce the significant medical consequences of cigarette use among PWHC.

IMPLICATIONS

People with chronic hepatitis C virus (HCV; PWHC) smoke cigarettes at a high prevalence, yet little is known about their smoking behaviors. Moreover, there are no cessation treatments targeting PWHC. This is the first study to collect focus group data from PWHC who smoke in order to identify reasons for cigarette use (HCV-related and non-HCV-related), and motivators and barriers to quitting cigarettes. PWHC reports using cigarettes to cope with the stress of an HCV diagnosis and to celebrate HCV cure. These findings suggest there are specific times during the HCV care continuum where providers can aid with cessation efforts.

Interaction between hepatitis B, hepatitis C and smoking in the development of hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

This meta-analysis reports the relationship between hepatitis B virus (HBV), hepatitis C virus (HCV), smoking and their combined impact on the development of hepatocellular carcinoma (HCC).

METHODS

We conducted a systematic search of PubMed, Web of Science and Scopus databases up to 15 July 2023. Observational studies investigating the association between HBV, HCV and smoking in the development of HCC were included. We assessed between-study heterogeneity using the I2 statistics. The effect sizes were estimated as odds ratio (OR) with 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Out of 20 794 studies identified in the initial search, 32 observational studies involving 22 282 participants met the inclusion criteria. Our meta-analysis showed that the combined impact of HBV and smoking was associated with an OR of 19.81 (95% CI: 14.77, 26.58), HCV and smoking was associated with an OR of 24.86 (95% CI: 12.41, 49.79), and coinfection of HBV and HCV was associated with an OR of 32.58 (95% CI: 20.57, 51.60).

CONCLUSIONS

Our findings indicate a significant interaction between HBV, HCV and smoking in the development of HCC and highlight the importance of addressing smoking cessation and viral hepatitis prevention and treatment as potential strategies for reducing HCC.

The association between alcohol, betel nut, and cigarette use with hepatitis C virus infection in Taiwan

Hepatitis C virus (HCV) infection may cause chronic liver disease, liver cirrhosis, and liver cancer. It has been reported to associate with habits including alcohol, betel nut and cigarette use. We aimed to investigate the association between alcohol, betel nut, and cigarette use with HCV infection in Taiwan and to explore their effects. A total of 121,421 participants were enrolled from the Taiwan Biobank. They were stratified into two groups according to whether they had (n = 2750; 2.3%) or did not have (n = 118,671; 97.7%) HCV infection. All participants were also classified into four groups according to the number of habits, including a history of alcohol drinking, betel nut chewing, and cigarette smoking. There were 85,406 (no habit), 24,299 (one habit), 8659 (two habits), and 3057 (three habits) participants in the four groups, respectively. Multivariable analysis showed that the participants who had an alcohol drinking history (odds ratio [OR] 1.568; 95% confidence interval [CI] 1.388-1.773; p < 0.001), betel nut chewing history (OR 1.664; 95% CI 1.445-1.917; p < 0.001), cigarette smoking history (OR 1.387; 95% CI 1.254-1.535; p < 0.001), were significantly associated with HCV infection. Furthermore, the participants were classified into four groups according to the number of habits as follows: 85,406 (no habit), 24,299 (one habit), 8659 (two habits), and 3057 (three habits). The HCV infection rates in these four groups were 2.11%, 2.14%, 3.23%, and 4.78%, respectively. Compared to the participants with no or one habit, those with two habits had a higher HCV infection rate (all p < 0.001). In addition, compared to the participants who had no, one or two habits, those who had three habits also had higher HCV infection rates (all p < 0.001). The participants who had three habits had the highest prevalence of HCV infection. In an era when most HCV can be cured, understanding the epidemiology link between habits and HCV may help the case finding.

Association between serum cotinine and volatile organic compounds (VOCs) in adults living with HIV, HBV, or HCV (NHANES 2005-2018)

Although people all know that nicotine in tobacco smoke is the key to cause health damage, they ignore the synergistic effect of a large number of Volatile Organic Compounds (VOCs) produced by incomplete tobacco combustion on nicotine or cotinine metabolism. Our aim is to investigate the association between serum VOCs and cotinine in smokers infected with HIV, HBV or HCV. National Health and Nutrition Examination Survey (NHANES 2005-2018) database, including 13,652 nationally representative subjects' sociodemographic characteristics and serological indicators, was used in this study. Smokers living with human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) were compared to non-infected population. The correlation between VOCs and cotinine as well as the effects of VOCs on cotinine metabolism were analyzed by Spearman correlation analysis and multivariable logistic regression analysis, respectively. Among HIV, HBV, or HCV infected smokers with the largest exposure dose to tobacco, the intensity of the association between VOCs and cotinine was the strongest. The results of multivariable binary logistic regression showed that high concentrations of 1,2-Dichlorobenzene (OR:1.036, CI:1.009-1.124), Benzene (OR:1.478, CI:1.036-2.292), Carbon Tetrachloride (OR:1.576, CI:1.275-2.085) and 2,5-Dimethylfuran (OR:1.091, CI:1.030-1.157) in blood might be independent risk factors leading to the increase of serum metabolite cotinine in smokers.

Evaluation of machine learning algorithms for predicting direct-acting antiviral treatment failure among patients with chronic hepatitis C infection

Despite the availability of efficacious direct-acting antiviral (DAA) therapy, the number of people infected with hepatitis C virus (HCV) continues to rise, and HCV remains a leading cause of liver-related morbidity, liver transplantation, and mortality. We developed and validated machine learning (ML) algorithms to predict DAA treatment failure. Using the HCV-TARGET registry of adults who initiated all-oral DAA treatment, we developed elastic net (EN), random forest (RF), gradient boosting machine (GBM), and feedforward neural network (FNN) ML algorithms. Model performances were compared with multivariable logistic regression (MLR) by assessing C statistics and other prediction evaluation metrics. Among 6525 HCV-infected adults, 308 patients (4.7%) experienced DAA treatment failure. ML models performed similarly in predicting DAA treatment failure (C statistic [95% CI]: EN, 0.74 [0.69-0.79]; RF, 0.74 [0.69-0.80]; GBM, 0.72 [0.67-0.78]; FNN, 0.75 [0.70-0.80]), and all 4 outperformed MLR (C statistic [95% CI]: 0.51 [0.46-0.57]), and EN used the fewest predictors (n = 27). With Youden index, the EN had 58.4% sensitivity and 77.8% specificity, and nine patients were needed to evaluate to identify 1 DAA treatment failure. Over 60% treatment failure were classified in top three risk decile subgroups. EN-identified predictors included male sex, treatment < 8 weeks, treatment discontinuation due to adverse events, albumin level < 3.5 g/dL, total bilirubin level > 1.2 g/dL, advanced liver disease, and use of tobacco, alcohol, or vitamins. Addressing modifiable factors of DAA treatment failure may reduce the burden of retreatment. Machine learning algorithms have the potential to inform public health policies regarding curative treatment of HCV.

Does Preoperative Antiviral Treatment for Hepatitis C Decrease Risk of Complications After Total Hip Arthroplasty? A Matched Cohort Study

BACKGROUND

Hepatitis C virus (HCV) is associated with increased complication risk after elective arthroplasty. The purpose of this study is to examine the impact of HCV and prearthroplasty antiviral treatment on complications following total hip arthroplasty (THA).

METHODS

A retrospective matched cohort study was conducted using an administrative claims database. In total, 6,883 HCV patients were matched 1:3 with 20,694 noninfected controls, and 920 HCV patients with antiviral treatment before THA (treated HCV) were matched 1:4 with 3,820 HCV patients without treatment (untreated HCV). Rates of 90-day medical complications and joint complications within 2 years postoperatively were compared with multivariable logistic regression.

RESULTS

HCV patients exhibited significantly increased rates of medical complications within 90 days compared to noninfected controls (all P < .01). At 2 years postoperatively, HCV patients also exhibited significantly higher risk of revision THA (odds ratio [OR] 1.81), dislocation (OR 2.06), mechanical complications (OR 1.40), periprosthetic fracture (OR 1.76), and prosthetic joint infection (PJI) (OR 1.79). However, treated HCV patients exhibited statistically comparable risk of all joint complications at 2 years postoperatively relative to controls (all P > .05). Compared to untreated HCV patients, treated HCV patients exhibited significantly lower risk of inpatient readmission within 90 days (OR 0.58) and PJI at 2 years postoperatively (OR 0.62).

CONCLUSION

HCV patients exhibit significantly increased risk of medical and joint complications following THA relative to controls, though prearthroplasty antiviral treatment mitigates complication risk. Treated HCV patients exhibited significantly lower risk of inpatient readmission and PJI compared to untreated HCV patients.

LEVEL OF EVIDENCE

Level III.

Association Between Chronic Hepatitis C Virus Infection and Esophageal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Chronic hepatitis C virus (HCV) infection is associated with increased risk of hepatobiliary tract cancer. However, whether chronic HCV infection is also associated with elevated risk of other types of cancer is still unknown. This systematic review and meta-analysis was conducted in order to investigate whether chronic HCV infection is positively associated with esophageal cancer.

METHODS

A systematic review was conducted using Embase and MEDLINE databases from inception to November 2019, with a search strategy that comprised the terms for "hepatitis C virus" and "cancer." Eligible studies were cohort studies consisting of patients with chronic HCV infection and comparators without HCV infection, and followed them for incident esophageal cancer. Hazard risk ratio, incidence rate ratio, relative risk or standardized incidence ratio of this association were extracted from each eligible study along with their 95% confidence intervals and were combined to calculate the pooled effect estimate using the random effect, generic inverse variance method.

RESULTS

A total of 20,459 articles were identified using this search strategy. After 2 rounds of independent review, 7 studies satisfied the inclusion criteria and were included in the meta-analysis. Chronic HCV infection was significantly associated with a higher incidence of esophageal cancer with the pooled relative risk of 1.61 (95% confidence interval: 1.19-2.17; I2=39%). The funnel plot was relatively symmetric which was not suggestive of publication bias.

CONCLUSION

This systematic review and meta-analysis demonstrated that there is a modest association between chronic HCV and incident esophageal cancer. However, more studies are needed to investigate the causality of this association.

Low Rates of Lung Cancer Screening Referrals in Patients With Human Immunodeficiency Virus: A Correlational Study

People living with HIV (PLWH) have an increased risk of lung cancer compared to the general population. In 2013, the United States Preventive Services Task Force (USPSTF) released their lung cancer screening (LCS) guidelines. However, the impact of these guidelines has not been well established in PLWH. The objective of this retrospective descriptive study is to evaluate the frequency of lung cancer screening referrals and factors associated with LCS referrals using the 2013 USPSTF screening guidelines in at-risk PLWH. We collected demographic and clinical information on PLWH from electronic medical records from July 2016 to July 2018. Descriptive statistics, chi-square tests, t-tests, Wilcoxon rank sum tests, and Fisher’s exact tests were used for analysis. Only 14% of patients who met 2013 USPSTF screening guidelines were referred for screening. Patients who received a referral were more likely to have received tobacco cessation counseling. Patients who received and completed a referral were more likely to have hepatitis C infection. Quality improvement strategies are needed to improve rates of LCS in PLWH.

HCV Cure and Cannabis Abstinence Facilitate Tobacco Smoking Quit Attempts in HIV-HCV Co-Infected Patients (ANRS CO13 HEPAVIH Cohort Study)

In Western countries, tobacco smoking is highly prevalent among patients co-infected with HIV and hepatitis C virus (HCV). In the era of antiretrovirals and HCV cure, smoking-related health damages contribute greatly to morbidity and mortality in HIV-HCV co-infected patients. We used longitudinal data from the ANRS CO13 HEPAVIH cohort to identify the correlates of tobacco smoking quit attempts (TSQA) in HIV-HCV co-infected patients. TSQA were modelled using a multivariable discrete-time Cox proportional hazards model in 695 HIV-HCV co-infected tobacco smokers. HCV cure was associated with a 76% higher chance of TSQA (adjusted hazard ratio [95% confidence interval]: 1.76 [1.06-2.93], p = 0.029), and cannabis use with a 37% lower chance (0.63 [0.40-1.00], p = 0.049), independently of the mode of HIV transmission, other psychoactive substance use, and body mass index. Patients should be screened for tobacco and cannabis use at HCV treatment initiation and during follow-up. They should also be provided with comprehensive counselling and referral to addiction services. Non-smoking routes of cannabis administration should be promoted for cannabis users who wish to quit smoking tobacco.

Characteristics of Adults With Hepatitis C Virus: Evidence From the National Health and Nutrition Examination Survey 2011-2012

Hepatitis C virus (HCV) infects more than 3 million people in the United States (U.S.). Long-term complications of hepatitis C infection result in increased liver disease and financial burden for the nation. The purpose of this study was to identify characteristics of adults with HCV in the U.S. This secondary, descriptive study analyzed data from the 2011-2012 National Health and Nutrition Examination Survey. The weighted sample included 2,075,749 adults diagnosed with HCV. Descriptive statistics were calculated. The findings revealed that most adults in the U.S. with HCV were insured non-Hispanic, white males, aged 45 to 64 years. Almost half of adults with HCV denied a liver condition. Several participants either were co-infected or had previous infection (82%) with other hepatitis. Substance use (53.5%), alcohol use (96%), and cigarette use (88.6%) among adults with HCV were higher than previously reported. A majority of adults were noncompliant with hepatitis A and B vaccination series completion (67% and 65.1%, respectively). Medication adherence was higher than other reported cases. Adults with HCV have increased mental health symptoms (67.1%) and do not routinely visit a mental health professional (90.2%). HCV-infected adults are likely to use alcohol, cigarettes, and/or other substances. Adults with HCV have significant mental health issues, but rarely access care. Medication adherence was higher than expected for this cohort. The findings provide information for nurses to develop individualized plans of care and identify at-risk individuals for treatment noncompliance.

Temporal trends in smoking and nicotine dependence in relation to co-occurring substance use in the United States, 2005-2016

BACKGROUND

Despite an overall decline in tobacco use in the United States, secular trends of smoking and nicotine dependence with co-occurring substance use are not well characterized.

METHODS

We examined self-reported tobacco and other substance use in 22,245 participants age 21-59 in the United States from six waves of the National Health and Nutrition Examination Survey (NHANES). Using Joinpoint regression, we assessed secular trends of smoking and nicotine dependence as a function of co-occurring use of alcohol, prescription opioids, marijuana/hashish, cocaine/heroin/methamphetamine, or other injection drug use. Multivariable logistic regressions were fitted to identify the potential risk factors.

RESULTS

During 2005-2016, the prevalence of current smoking decreased (without co-occurring substance use: 17.0 %-12.7 %; with co-occurring use of one substance: 35.3 % to 24.6 %; with co-occurring use of two or more substances: 53.8 %-42.2 %), and moderate-to-severe nicotine dependence decreased as well (8.0 %-4.2 %, 16.0 %-8.8 %, and 23.9 %-15.7 %, respectively). Smoking and nicotine dependence were more likely in those with co-occurring use of one substance (current smoking: odds ratio [OR] = 2.22, 95 % confidence interval [CI] = 2.01-2.45); nicotine dependence: OR = 1.88, 95 % CI = 1.63-2.17) and in those with co-occurring use of two or more substances (current smoking: OR = 5.25, 95 % CI = 4.63-5.95; nicotine dependence: OR = 3.24, 95 % CI = 2.72-3.87).

CONCLUSIONS

Co-occurring substance use was associated with smaller reductions in tobacco use, over time, and with increased odds of nicotine dependence. This suggests that co-occurring substance users should be regarded as a tobacco-related disparity group and prioritized for tobacco control interventions.

Hepatitis C virus screening of high-risk patients in a community hospital emergency department: Retrospective review of patient characteristics and future implications

Background

Chronic hepatitis C virus infection (HCV) is a common infectious disease that affects more than 2.7 million people in the US. Because the emergency department (ED) can present an ideal opportunity to screen patients who may not otherwise get routine screening, we implemented a risk-based screening program for ED patients and established a system to facilitate linkage to care.

Methods and findings

A risk-based screening algorithm for HCV was programmed to trigger an alert in Epic electronic medical record system. Patients identified between August 2018 and April 2020 in the ED were tested for HCV antibody reflex to HCV RNA. Patients with a positive screening test were contacted for the confirmatory test result and to establish medical care for HCV treatment. Patient characteristics including age, sex, self-awareness of HCV infection, history of previous HCV treatment, history of opioids use, history of tobacco use, and types of insurance were obtained.

A total of 4,525 patients underwent a screening test, of whom 131 patients (2.90%) were HCV antibody positive and 43 patients (0.95%) were HCV RNA positive, indicating that only 33% of patients with positive screening test had chronic HCV infection. The rate of chronic infection was higher in males as compared to females (1.34% vs 0.60%, p = 0.01). Patients with history of opioid use or history of tobacco use were found to have a lower rate of spontaneous clearance than patients without each history (opioids: 48.6% vs 72.0%, p = 0.02; tobacco: 56.6% vs 80.5%, p = 0.01). Among 43 patients who were diagnosed with chronic hepatitis C, 26 were linked to a clinical setting that can address chronic HCV infection, with linkage to care rate of 60.5%. The most common barrier to this was inability to contact patients after discharge from the ED.

Conclusions

A streamlined EMR system for HCV screening and subsequent linkage to care from the ED can be successfully implemented. A retrospective review suggests that male sex is related to chronic HCV infection, and history of opioid use or history of tobacco use is related to lower HCV spontaneous clearance.

Factors and HCV treatment outcomes associated with smoking among people who inject drugs on opioid agonist treatment: secondary analysis of the PREVAIL randomized clinical trial

Background

Cigarette smoking has emerged as a leading cause of mortality among people with hepatitis C virus (HCV). People who inject drugs (PWID) represent the largest group of adults infected with HCV in the US. However, cigarette smoking remains virtually unexplored among this population. This study aimed at (1) determining prevalence and correlates of cigarette smoking among HCV-infected PWID enrolled in opiate agonist treatment programs; (2) exploring the association of smoking with HCV treatment outcomes including adherence, treatment completion and sustained virologic response (SVR); and 3) exploring whether cigarette smoking decreased after HCV treatment.

Methods

Participants were 150 HCV-infected PWID enrolled in a randomized clinical trial primarily designed to test three intensive models of HCV care. Assessments included sociodemographics, presence of chronic health and psychiatric comorbidities, prior and current drug use, quality of life, and HCV treatment outcomes.

Results

The majority of the patients (84%) were current cigarette smokers at baseline. There was a high prevalence of psychiatric and medical comorbidities in the overall sample of PWID. Alcohol and cocaine use were identified as correlates of cigarette smoking. Smoking status did not influence HCV treatment outcomes including adherence, treatment completion and SVR. HCV treatment was not associated with decreased cigarette smoking.

Conclusions

The present study showed high prevalence of cigarette smoking among this population as well as identified correlates of smoking, namely alcohol and cocaine use. Cigarette smoking was not associated with HCV treatment outcomes. Given the detrimental effects that cigarette smoking and other co-occurring, substance use behaviors have on HCV-infected individuals’ health, it is imperative that clinicians treating HCV also target smoking, especially among PWID. The high prevalence of cigarette smoking among PWID will contribute to growing morbidity and mortality among this population even if cured of HCV. Tailored smoking cessation interventions for PWID along with HCV treatment may need to be put into clinical practice.

Trial registration

NCT01857245. Registered May 20, 2013.

A Cross-Sectional Analysis of Tobacco Use and Concurrent Alcohol and Substance Use Among Patients Living with HIV/HCV Co-infection: Findings from a Large Urban Tertiary Center

This study aimed to assess the prevalence of and factors associated with tobacco use among patients living with HIV/HCV co-infection. Patient reported outcomes (PROs) were analyzed of patients living with HIV/HCV co-infection (n = 313) who presented for clinical evaluation and treatment of HCV between 2013 and 2017 at a university-affiliated HIV/HCV Co-infection Clinic. The prevalence of tobacco use in patients living with HIV/HCV co-infection was 48%. Compared to non-smokers, a higher proportion of tobacco smokers had substance use disorders and concurrent alcohol and substance use. In the multivariate analysis, concurrent alcohol and substance use was positively associated with tobacco use. The findings suggest clinical interventions are urgently needed to reduce tobacco use among patients living with HIV/HCV co-infection—a doubly-vulnerable immunocompromised population. Otherwise, failed efforts to dedicate resources and targeted behavioral interventions for this respective population will inhibit survival—especially considering the recent and evolving COVID-19 pandemic.

Prevalence of oral conditions among methamphetamine users: NHANES 2009-2014

OBJECTIVES

Methamphetamine (MA) is a widely used illicit drug and a nationwide public health concern. Although dental complications are consistently reported among MA users, yet limited nationally representative studies on the associations between MA use and oral health currently exist.

METHODS

Using the National Health and Nutrition Examination Survey 2009-2014, we analyzed 8,762 respondents aged 30-64 years who had completed a periodontal examination. MA use was self-reported; periodontitis, untreated caries, and missing teeth were assessed by calibrated dentists. Descriptive statistics as well as multivariable regression analyses were performed. Data were weighted to yield representative estimates of the US adult population.

RESULTS

Overall 7.8 percent of US adults aged ≥30 years had ever used MA. Ever-use prevalence was higher among males, whites, and individuals below the federal poverty level. Established MA users had a higher prevalence of untreated dental caries (36.6 percent), any periodontitis (54.8 percent), and severe periodontitis (12.2 percent) than those who had never used MA. The prevalence of any periodontitis was higher among current MA users (PR: 1.31; 95% CI: 1.05-1.62) than those who never used MA. Prevalence of untreated dental caries was higher among current MA users (PR: 1.53; 95% CI: 1.10-2.13) and established users (PR: 1.21; 95% CI: 1.02-1.48) than never users. Taking MA orally and/or through injection was associated with higher odds of severe periodontitis than orally only (AOR: 3.72; CI: 1.79-7.75).

CONCLUSIONS

MA users had a higher prevalence of periodontitis and dental caries. Continued research assessing the relationship between MA use and oral health can inform clinical interventions and management of dental diseases in MA users.

Comparing Treatment Response Between Older and Younger Patients with Chronic Hepatitis C Virus Infection on Direct-acting Antiviral Agents

OBJECTIVE

To compare sustained virologic response 12 weeks post-treatment completion (SVR12) and patient characteristics for older versus younger patients with chronic hepatitis C virus infection (HCV) receiving direct-acting antiviral (DAA) agent therapy.

METHODS

This retrospective cohort study included patients with chronic HCV who received DAA therapy, between 2015 and 2018, in the largest health system in Rhode Island (N=154). Patient characteristics, comorbid diagnoses, and SVR12 status were compared between older (aged ≥60 years) and younger (<60 years) adults using chi-squared tests.

RESULTS

Overall, 94.1% (95% CI: 90.4-97.8) achieved SVR12; response rates were 91.8% (95% CI: 84.9-98.6) for older adults and 95.6% (95% CI: 91.5-99.8) for younger adults (p=0.51).

CONCLUSIONS

Our findings refute the historical notion that older adults were a "difficult-to-treat" subpopulation for whom clinicians should expect less treatment success. This is no longer the case with DAA therapy.

Bayesian network modelling study to identify factors influencing the risk of cardiovascular disease in Canadian adults with hepatitis C virus infection

OBJECTIVES

The present study evaluates the extent of association between hepatitis C virus (HCV) infection and cardiovascular disease (CVD) risk and identifies factors mediating this relationship using Bayesian network (BN) analysis.

DESIGN AND SETTING

A population-based cross-sectional survey in Canada.

PARTICIPANTS

Adults from the Canadian Health Measures Survey (n=10 115) aged 30 to 74 years.

PRIMARY AND SECONDARY OUTCOME MEASURES

The 10-year risk of CVD was determined using the Framingham Risk Score in HCV-positive and HCV-negative subjects. Using BN analysis, variables were modelled to calculate the probability of CVD risk in HCV infection.

RESULTS

When the BN is compiled, and no variable has been instantiated, 73%, 17% and 11% of the subjects had low, moderate and high 10-year CVD risk, respectively. The conditional probability of high CVD risk increased to 13.9%±1.6% (p<2.2×10^-16) when the HCV variable is instantiated to 'Present' state and decreased to 8.6%±0.2% when HCV was instantiated to 'Absent' (p<2.2×10^-16). HCV cases had 1.6-fold higher prevalence of high-CVD risk compared with non-infected individuals (p=0.038). Analysis of the effect modification of the HCV-CVD relationship (using median Kullback-Leibler divergence; D_KL ) showed diabetes as a major effect modifier on the joint probability distribution of HCV infection and CVD risk (D_KL =0.27, IQR: 0.26 to 0.27), followed by hypertension (0.24, IQR: 0.23 to 0.25), age (0.21, IQR: 0.10 to 0.38) and injection drug use (0.19, IQR: 0.06 to 0.59).

CONCLUSIONS

Exploring the relationship between HCV infection and CVD risk using BN modelling analysis revealed that the infection is associated with elevated CVD risk. A number of risk modifiers were identified to play a role in this relationship. Targeting these factors during the course of infection to reduce CVD risk should be studied further.

The Association of Abnormal Liver Tests with Hepatitis C Testing in Primary Care

BACKGROUND

As hepatitis C virus birth cohort (1945-1965) screening in primary care improves, testing patterns in response to persistently abnormal liver tests are less well known.

METHODS

This retrospective cohort study of a patient-centered medical home between 2007 and 2016 evaluates the association of abnormal liver chemistries and other clinical and demographic factors with hepatitis C antibody (HCV Ab) testing in patients with persistently abnormal liver tests. Patients with at least 2 consecutive abnormal liver tests were categorized by the clinical pattern of liver chemistry abnormality, including cholestatic, hepatocellular, and mixed patterns. The primary outcomes were: 1) completed HCV Ab tests; and 2) positive HCV Ab results for those patients tested.

RESULTS

Of 4512 patients with consecutive abnormal liver tests, only 730 (16%) underwent HCV Ab testing within 1 year of the second abnormality; 81/730 (11%) had HCV Ab detected. A logistic regression model revealed that mixed (odds ratio [OR] 2.20; 95% confidence interval [CI], 1.72-2.82) and hepatocellular (OR 1.43; 95% CI, 1.15-1.79) patterns of liver test abnormality, female sex, and alcohol and tobacco abuse were associated with higher odds of HCV Ab testing. Hepatocellular (OR 7.51; 95% CI, 2.18-25.94) and mixed patterns (OR 5.88; 95% CI, 1.64-21.15) of liver test abnormalities, male sex, Medicaid enrollment, and drug and tobacco abuse had higher odds of positive HCV Ab results.

CONCLUSIONS

There is opportunity to improve hepatitis C diagnostic testing in patients with consecutively elevated liver tests, and hepatocellular and mixed patterns of abnormality should prompt primary care providers to action.

Lower risk of multiple sclerosis in patients with chronic hepatitis C: a nationwide population-based registry study

Background

Multiple sclerosis (MS) is an immune-mediated neurological disease that causes demyelination. The etiology is unknown, but patients with a previous viral infection, such as Epstein–Barr virus, have been shown to be at a higher risk of developing MS. In contrast, people living with HIV have a lower risk of developing MS. Hepatitis C virus (HCV) mainly infects the liver, but patients with HCV can experience several extrahepatic manifestations and studies have shown an association with several autoimmune conditions such as neuropathy and myelitis. The present study aimed to investigate the risk of MS in patients with chronic HCV infection compared with matched comparators.

Methods

Patients were identified using the nationwide Swedish inpatient (2001–2013) and outpatient care registers (2001–2013) for HCV (B18.2) and MS (G35) according to the International Classification of Diseases-10. Up to five comparators (matched on age/sex/place of residency) were drawn from the general population for each HCV patient. Follow-up started at the first HCV visit from 2001 and the patients’ accrued person-time until death, emigration or 31 December 2013. Risk of MS diagnosis was calculated as standardized incidence ratio (SIR) with 95% confidence intervals (CIs).

Results

HCV patients were at lower risk of MS diagnosis (SIR 0.37; 95% CI 0.26–0.50). The incidence of MS during the study in the HCV cohort was 0.087% compared with 0.27% in the matched comparator cohort.

Conclusion

Surprisingly, these data suggest HCV patients to have a lower risk of MS diagnosis.

Electronic supplementary material

The online version of this article (10.1007/s00415-019-09397-8) contains supplementary material, which is available to authorized users.