title: Using Respondent-Driven Sampling to Recruit Illegal Drug Purchasers to Evaluate a Drug Market Intervention.
abstract: Violent drug markets are not as prominent as they once were in the United States, but they still exist and are associated with significant crime and lower quality of life. The drug market intervention (DMI) is an innovative strategy that uses focused deterrence, community engagement, and incapacitation to reduce crime and disorder associated with these markets. Although studies show that DMI can reduce crime and overt drug activity, one perspective is prominently missing from these evaluations: those who purchase drugs.
  
  
  
  This study explores the use of respondent-driven sampling (RDS)-a statistical sampling method-to approximate a representative sample of drug users who purchased drugs in a targeted DMI market to gain insight into the effect of a DMI on market dynamics.
  
  
  
  Using RDS, we recruited individuals who reported hard drug use (crack or powder cocaine, heroin, methamphetamine, or illicit use of prescriptions opioids) in the last month to participate in a survey. The main survey asked about drug use, drug purchasing, and drug market activity before and after DMI; a secondary survey asked about network characteristics and recruitment.
  
  
  
  Our sample of 212 respondents met key RDS assumptions, suggesting that the characteristics of our weighted sample approximate the characteristics of the drug user network. The weighted estimates for market purchasers are generally valid for inferences about the aggregate population of customers, but a larger sample size is needed to make stronger inferences about the effects of a DMI on drug market activity.
authors.affiliation: RAND Corporation, Santa Monica, CA, USA ober@rand.org.
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Ober
authors.affiliation: Precision Health Economics, San Francisco, CA, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Sussell
authors.affiliation: RAND Corporation, Santa Monica, CA, USA.
authors.forename: Beau
authors.initials: B
authors.lastname: Kilmer
authors.affiliation: RAND Corporation, Santa Monica, CA, USA.
authors.forename: Jessica
authors.initials: J
authors.lastname: Saunders
authors.affiliation: Cornell University, Ithaca, NY, USA.
authors.forename: Douglas D
authors.initials: DD
authors.lastname: Heckathorn
mesh_terms: D000328:Adult; D000367:Age Factors; D003415:Crime / Q000706:statistics & numerical data*; D055030:Drug Users / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000009:adverse effects / Q000600:supply & distribution*; D008297:Male; D040541:Marketing; D008875:Middle Aged; D015233:Models, Statistical; D020380:Needs Assessment; D015995:Prevalence; D018570:Risk Assessment; D012494:Sampling Studies; D012737:Sex Factors; D019966:Substance-Related Disorders / Q000517:prevention & control*; D014481:United States; D055815:Young Adult
chemical_list: D013287:Illicit Drugs
keywords: content area; crime and justice; design and evaluation of programs and policies; methodology; outcome evaluation; survey methodology