INTRODUCTION: Use of pre-exposure prophylaxis (PrEP) among people who inject 
drugs (PWID) has been shown to be effective in preventing HIV transmission. We 
examined correlates of the willingness to use PrEP among community-recruited 
older PWID in Washington, DC.
METHODS: PWID were recruited using respondent-driven sampling (RDS) and 
completed a behavioral interview for the National HIV Behavioral Surveillance 
system in 2012. Participants reported on willingness to use PrEP and how it 
might affect their drug use and sexual behaviors. We reported RDS-weighted 
proportions and multivariable correlates of being willing to use PrEP.
RESULTS: Among 304 participants, 69% were male, and the majority was aged ≥50 
and black. Only 13.4% had ever heard of using anti-HIV medication to prevent 
HIV; none had ever used PrEP or knew anyone who used it in the past year. 
Forty-seven percent were very likely and 24% were somewhat likely to take PrEP 
if it were available without cost; 13% agreed they would not need to 
sterilize/clean needles or use condoms if taking PrEP. Correlates of being very 
likely to use PrEP included being younger (<50years), sharing cookers, cotton or 
water in the past year, and believing they would no longer need to use clean 
needles.
CONCLUSION: Nearly half of PWID reported being very willing to use PrEP if it 
were available without cost. Younger PWID and those at higher risk of sharing 
cookers, cotton or water were more willing to use PrEP, suggesting a focus on 
these groups to explore PrEP use among PWID.