title: A randomised controlled trial of financial incentives to increase hepatitis B vaccination completion among people who inject drugs in Australia.
abstract: OBJECTIVE
  This study aimed to investigate the efficacy of modest financial incentives in increasing completion of an accelerated 3-dose hepatitis B virus (HBV) vaccination schedule (0, 7, 21days) among people who inject drugs (PWID).
  
  
  METHODS
  Randomised controlled trial. Participants were randomly allocated to receive $30 Australian Dollars cash following receipt of vaccine doses two and three ('incentive condition'), or standard care ('control condition'). Serologically confirmed HBV-susceptible PWID. Two inner-city health services and a field study site in Sydney, Australia. The primary outcome was completion of the vaccination series. Additional assessments included self-reported demographic, drug use and treatment, and risk-taking histories.
  
  
  RESULTS
  Compared to the control condition, significantly more participants in the incentive condition received all three vaccine doses, under intention-to-treat analyses (n=139; 87% versus 66%; p=.004); and within the specified window periods under per protocol analyses (n=107 received three vaccine doses; 92% versus 67%; p=.001). Multivariate analysis indicated that the incentive condition and longer injecting histories significantly increased the likelihood of series completion. Aboriginal/Torres Strait Islanders were significantly less likely to complete the series.
  
  
  CONCLUSIONS
  Modest financial incentives, per-dose, increased adherence to the accelerated HBV vaccination schedule among PWID. Results have implications for increasing HBV and, potentially, other vaccine-preventable infections, among PWID.
authors: The Kirby Institute, University of New South Wales, NSW 2052, Australia.
authors: Libby
authors: L
authors: Topp
authors: Carolyn A
authors: CA
authors: Day
authors: Handan
authors: H
authors: Wand
authors: Rachel M
authors: RM
authors: Deacon
authors: Ingrid
authors: I
authors: van Beek
authors: Paul S
authors: PS
authors: Haber
authors: Marian
authors: M
authors: Shanahan
authors: Craig
authors: C
authors: Rodgers
authors: Lisa
authors: L
authors: Maher
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D005260:Female; D006509:Hepatitis B / Q000517:prevention & control*; D017325:Hepatitis B Vaccines / Q000191:economics / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009042:Motivation; D010349:Patient Compliance / Q000523:psychology* / Q000706:statistics & numerical data; D015819:Substance Abuse, Intravenous / Q000523:psychology*; D055815:Young Adult
chemical_list: D017325:Hepatitis B Vaccines
keywords: Conditional cash transfers; Contingency management; Hepatitis B; People who inject drugs; Vaccination