Concordance between drug users' and their network members' reported drug use and HIV status: implications to HIV prevention

This chapter examines accuracy of data on characteristics and behaviors of network ties by assessing concordance between 327 indexes' reports on their 411 network members and the network members' self-reports. Participants were recruited for an HIV prevention intervention. Almost all (99%) participants had a history of drug use. Concordance rates varied by the type of information reported and raters' characteristics and behaviors. Overall, substantial concordance (kappa = 0.68) was found for reports of network member's HIV status, with sex partners having greater concordance (kappa = 0.80) compared to HIV seronegative and current drug using indexes (kappas ranged 0.55-0.61). Yet, participants generally, and HIV seronegatives especially, tended to underestimate HIV infection of their network members. Reports of network members' current drug use (kappa = 0.45), current injection drug use (kappa = 0.58), and employment (kappa = 0.52) showed moderate concordance, and age showed near perfect concordance (kappa = 0.90). Results suggest that former and current drug users can provide reasonably accurate data about the HIV status and drug use of their network members. Implications to HIV prevention are discussed.