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Journal Club. Alcohol and Health: Current Evidence January-February 2006. Featured Article. Alcohol has no effect on hepatitis C virus replication: a meta-analysis Anand BS, et al. Gut . 2005;54:1468-1472. Study Objective. To examine whether…
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Journal Club Alcohol and Health: Current Evidence January-February 2006 www.alcoholandhealth.org
Featured Article Alcohol has no effect on hepatitis C virus replication: a meta-analysis Anand BS, et al. Gut. 2005;54:1468-1472. www.alcoholandhealth.org
Study Objective To examine whether… • alcohol stimulates replication of the hepatitis C virus (HCV) www.alcoholandhealth.org
Study Design • Systematic review and meta-analysis of 14 studies that assessed the association between alcohol use and hepatitis C virus replication www.alcoholandhealth.org
Users’ Guides for How to Use Review Articles • Are the results of the study valid? • What are the results? • Will the results help me in caring for my patients? www.alcoholandhealth.org
Are the Results of the Study Valid? • Did the overview address a focused clinical question? • Were the criteria used to select articles for inclusion appropriate? • Is it unlikely that important, relevant studies were missed? • Was the validity of the included studies appraised? • Were assessments of studies reproducible? • Were the results similar from study to study? www.alcoholandhealth.org
Did the overview address a focused clinical question? • Yes. • The question was whether alcohol consumption influences HCV viral levels. www.alcoholandhealth.org
Were the criteria used to select articles for inclusion appropriate? • The most valid study design to assess the effect of alcohol on HCV viral levels is a randomized trial. • However, given ethical and feasibility concerns, these studies are not likely common. • Researchers included studies of humans that reported current alcohol consumption and HCV viral titres (and the methods of measurement). www.alcoholandhealth.org
Is it unlikely that important, relevant studies were missed? • Yes. • The search strategy included… • studies since 1989 when the virus was first described, • studies identified in major databases, • abstracts, and • non-English language articles. www.alcoholandhealth.org
Was the validity of the included studies appraised? • The authors did not report the validity or quality of the individual studies. • They did note that some studies did not report viral titres. www.alcoholandhealth.org
Were assessments of studies reproducible? • No information was provided on... • who assessed the studies or • whether the assessments were reproducible. www.alcoholandhealth.org
Were the results similar from study to study? • Study results were heterogeneous. www.alcoholandhealth.org
What Are the Results? • What are the overall results of the review? • How precise were the results? www.alcoholandhealth.org
What are the overall results of the review? • 3 of 9 studies showed significantly higher hepatitis C viral levels in heavy drinkers (defined variably) than in nondrinkers. • However, this difference was no longer significant when data from all 9 studies were combined. www.alcoholandhealth.org
What are the overall results of the review (continued)? • Hepatitis C viral levels did not increase significantly as alcohol use increased, based on combined data from 4 studies of nondrinkers and moderate and heavy drinkers. • In 5 small studies (59 subjects total), HCV titres were measured in the same subjects before and after abstinence. • In 2 studies, titres decreased with abstinence. • In 2 studies, titres decreased with abstinence in about half of subjects. • In the remaining study, titres did not change with abstinence. www.alcoholandhealth.org
How precise were the results? • The confidence interval (CI) around the effect size of alcohol use on HCV levels was –0.31 to +1.17. • The CI included no effect, a positive effect, and a negative effect. www.alcoholandhealth.org
Will the Results Help Me in Caring for My Patients? • Can the results be applied to my patient care? • Were all clinically important outcomes considered? www.alcoholandhealth.org
Can the results be applied to my patient care? • It is not clear whether the results can be applied in practice. • The study question remains unanswered because of… • methodological limitations of some of the studies, • small samples, and • a wide confidence interval around the main finding. • A consistent effect of alcohol on HCV viral levels was not detected, but it was also not excluded. www.alcoholandhealth.org
Were all clinically important outcomes considered? • Increased HCV viral levels are one possible effect of alcohol on hepatitis C infection. • More important outcomes of interest include a range of markers of disease progression, such as hepatic failure and death. www.alcoholandhealth.org