The impact of methadone maintenance therapy on hepatitis C incidence among illicit drug users.

Abstract

AIMS:

To determine the relationship between methadone maintenance therapy (MMT) and hepatitis C (HCV) seroconversion among illicit drug users.

DESIGN:

A generalized estimating equation model assuming a binomial distribution and a logit-link function was used to examine for a possible protective effect of MMT use on HCV incidence.

SETTING:

Data from three prospective cohort studies of illicit drug users in Vancouver, Canada between 1996 and 2012.

PARTICIPANTS:

A total of 1004 HCV antibody-negative illicit drug users stratified by exposure to MMT.

MEASUREMENTS:

Baseline and semi-annual HCV antibody testing and standardized interviewer-administered questionnaire soliciting self-reported data relating to drug use patterns, risk behaviors, detailed socio-demographic data and status of active participation in an MMT program.

FINDINGS:

One hundred and eighty-four HCV seroconversions were observed for an HCV incidence density of 6.32 [95% confidence interval (CI) = 5.44-7.31] per 100 person-years. After adjusting for potential confounders, MMT exposure was protective against HCV seroconversion [adjusted odds ratio (AOR) = 0.47; 95% CI = 0.29-0.76]. In subanalyses, a dose-response protective effect of increasing MMT exposure on HCV incidence (AOR = 0.87; 95% CI = 0.78-0.97) per increasing 6-month period exposed to MMT was observed.

CONCLUSION:

Participation in methadone maintenance treatment appears to be highly protective against hepatitis C incidence among illicit drug users. There appears to be a dose-response protective effect of increasing methadone exposure on hepatitis C incidence.

• Authors: Seonaid Nolan, Viviane Dias Lima, Nadia Fairbairn, Thomas Kerr, Julio Montaner, Jason Grebely, Evan Wood
• Journal: Addiction (Abingdon, England) (Addiction) Vol. 109 Issue 12 Pg. 2053-9 (Dec 2014) ISSN: 1360-0443 [Electronic] England
• PMID: 25041346 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 Society for the Study of Addiction.

Chemical References

• Illicit Drugs
• Methadone

Topics

• Adult
• Alcoholism (epidemiology, rehabilitation)
• British Columbia
• Cohort Studies
• Female
• Hepatitis C (epidemiology)
• Humans
• Illicit Drugs
• Male
• Methadone (administration & dosage)
• Opiate Substitution Treatment
• Opioid-Related Disorders (epidemiology, rehabilitation)
• Prospective Studies
• Seroconversion
• Substance-Related Disorders (epidemiology, rehabilitation)
• Young Adult