A randomized controlled trial of monetary incentives vs. outreach to enhance adherence to the hepatitis B vaccine series among injection drug users

doi:10.1016/S0376-8716(03)00074-7

Drug and Alcohol Dependence

Volume 71, Issue 2, 20 August 2003, Pages 127-131

https://doi.org/10.1016/S0376-8716(03)00074-7 Get rights and content

Abstract

Background: Injection drug users (IDUs) are at high-risk for hepatitis B virus (HBV) and HIV. Due to concerns about non-adherence to multi-dose vaccine regimens however, IDUs are severely under-immunized against HBV and have been excluded from phase III trials of multi-dose candidate HIV vaccines in the United States. Methods: Through a randomized controlled trial, we compared the effectiveness of monetary incentives versus outreach to improve IDUs’ adherence to the 3-dose hepatitis B vaccine. In 1998–1999, HBV-susceptible IDUs were recruited from San Francisco streets. Eligible participants received their first dose of vaccine and were randomized to either receive monthly monetary incentives (n=48) or maintain weekly contact with an outreach worker (n=48) during the 6-month vaccine series. Results: All 3 doses of vaccine were received by 33 (69%) of IDUs in the monetary incentive arm and 11 (23%) in the outreach arm (odds ratio=13.8; 95% confidence interval, 2.9, 128; P<0.0001). In a multivariate model, receiving monetary incentives was independently associated with vaccine completion (AOR=10.3; 95% CI=3.7, 29.0). Conclusions: Among IDUs, monetary incentives are superior to outreach in achieving adherence to the multi-dose hepatitis B vaccine series. Monetary incentives may be adapted to future multi-dose candidate HIV vaccine trials in IDUs.

Introduction

Although hepatitis B virus (HBV) infection has been preventable since the development of the hepatitis B vaccine in 1982, over 80% of injection drug users (IDUs) have markers of prior hepatitis B infection (Levine et al., 1995, Alter et al., 1990) and only 5–10% have been immunized (Seal et al., 2000a, Alter et al., 1990). Poor adherence among IDUs is cited as the main deterrent to initiating the hepatitis B vaccine series in this population (Alter et al., 1990). Among IDUs, barriers to hepatitis B vaccine adherence include lack of access to care, competing needs, poor relationships with health care providers, and lack of education or information (Seal et al., 2000a, Levine et al., 1995, Heimer et al., 2002). Concerns about adherence have resulted in IDUs not being offered available multi-dose vaccines such as the hepatitis B vaccine (Francis, 1995) nor enrollment in Phase III trials of HIV candidate vaccines in the United States (Strathdee S., personal communication, 2001) (Francis et al., 1998, Vlahov, 1994).

The hepatitis B vaccine is a 3-dose vaccine series administered over 6 months (0, 1, and 6), similar to some multi-dose candidate HIV vaccines. Strategies that enhance adherence to hepatitis B vaccine among IDUs may thus serve as a model for HIV candidate vaccine delivery in IDUs. Adherence to healthcare interventions among IDUs has been enhanced using innovative strategies (Tulsky et al., 2000; Lorvick et al., 1999; Deren et al., 1994), and strategies intended to overcome barriers to vaccination are essential to immunize this high-risk population. We compared two strategies intended to improve adherence to the 3-dose hepatitis B vaccine series by randomizing a sample of street-recruited IDUs to either receive monthly monetary incentives or to be contacted weekly by an outreach worker over the 6-month immunization period. We report our findings and suggest strategies for enhancing adherence to the hepatitis B vaccine series which may be adapted to future multi-dose vaccines trials in this high-risk population.

Section snippets

Methods

In October 1998 and December 1999, 366 IDUs were recruited from the streets in two inner-city San Francisco neighborhoods using targeted sampling techniques (Kral et al., 2001). Structured interviews were conducted by trained interviewers to assess demographics and sexual and injection risk behaviors and health services utilization. Hepatitis B-related knowledge was assessed by asking participants whether they agreed or disagreed with the following statements: Hepatitis B can lead to: (1)

Results

Of 366 IDUs, 149 (41%) were eligible for enrollment: 73 (20%) were negative for all three HBV seromarkers and 76 (21%) had isolated anti-HBc. Of those eligible, 96 (64%) returned for enrollment and accepted their first dose of hepatitis B vaccine. There were no statistically significant differences (P<0.05) with respect to demographics, sexual and injection risk behaviors, HBV-related knowledge or attitudes regarding vaccines between IDUs enrolled and those not enrolled in the study.

Forty-eight

Discussion

This study demonstrates that, among IDUs, monthly monetary incentives are significantly more effective and less costly than outreach in achieving adherence to the 6-month, 3-dose hepatitis B vaccine. It also shows that most IDUs can complete a multi-dose vaccine series when conditions are optimized. Successful adherence strategies for IDUs may be adapted from hepatitis B vaccine trials to other multi-dose vaccine trials.

The participants in this study were socially marginalized; and, since many

Acknowledgements

This study was funded by the National Institutes on Drug Abuse (RO1-DA11860) and some of the hepatitis B vaccine series were donated by the San Francisco Department of Public Health. We wish to thank the staff of the Urban Health Study for all of their hard work on this study, especially Paula Laird, Sybil Marcus, Jeff Moore, and Greg Austin. We are grateful to Robert Heimer for his insightful comments.

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Citation Excerpt :
Several strategies to improve vaccine participation and completion have been studied, including contingency management, vaccination programmes in prisons, on-site vaccination during education sessions, as well as newly approved 2 dose shortened vaccination schedules which can be accomplished in 1 month. In particular, the use of monetary incentives to encourage patients to return to clinics to complete the vaccination series has been shown to be cost effective and a worthwhile use of healthcare resources to control transmission.154–157 One study of contingency management in the UK reported a vaccination completion percentage between 40%–50% for those who were offered monetary incentives, versus 9% for those who received the standard vaccination regimen without additional benefits.151
Opioid use in the United States and in many parts of the world has reached epidemic proportions. This has led to excess mortality as well as significant changes in the epidemiology of liver disease. Herein, we review the impact of the opioid epidemic on liver disease, focusing on the multifaceted impact this epidemic has had on liver disease and liver transplantation. In particular, the opioid crisis has led to a significant shift in incident hepatitis C virus infection to younger populations and to women, leading to changes in screening recommendations. Less well characterized are the potential direct and indirect hepatotoxic effects of opioids, as well as the changes in the incidence of hepatitis B virus infection and alcohol abuse that are likely rising in this population as well. Finally, the opioid epidemic has led to a significant rise in the proportion of organ donors who died due to overdose. These donors have led to an overall increase in donor numbers, but also to new considerations about the better use of donors with perceived or actual risk of disease transmission, especially hepatitis C. Clearly, additional efforts are needed to combat the opioid epidemic. Moreover, better understanding of the epidemiology and underlying pathophysiology will help to identify and treat liver disease in this high-risk population.
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Targeted vaccination strategies are necessary to prevent people who use drugs (PWUD) becoming infected with hepatitis B virus (HBV). The aims of this study were to provide an overview of the activities for PWUD in a decentralised vaccination program in the Netherlands and to explore the determinants associated with completing a standard hepatitis B vaccination series.
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A randomized controlled trial of monetary incentives vs. outreach to enhance adherence to the hepatitis B vaccine series among injection drug users

Abstract

Introduction

Section snippets

Methods

Results

Discussion

Acknowledgements

Drug Alcohol Depend.

Am. J. Med.

Lancet

The changing epidemiology of hepatitis B in the United States: need for alternative vaccination strategies

JAMA

Harnessing peer networks as an instrument for AIDS prevention: results from a peer-driven intervention

Pub. Health Rep.

Effects of an incentive and education program on return rates for PPD test reading in patients with HIV infection

J. Acquir. Immune Defic. Syndrome Human Retrovirol.

The impact of providing incentives for attendance at AIDS prevention sessions

Pub. Health Rep.

Monetary incentives: a useful strategy for enhancing enrollment and promoting participation in HIV/STD risk reduction interventions

Sex Transm. Infect.

Reliability of drug users’ self-reported HIV risk behaviors and validity of self-reported recent drug use

Assessment

The public's health unprotected. Reversing a decade of underutilization of hepatitis B vaccine

JAMA

Advancing AIDSVAX to phase 3. Safety, immunogenicity, and plans for phase 3

AIDS Res. Human Retroviruses

Should we pay the patient? Review of financial incentives to enhance patient compliance

Br. Med. J.