overall. Data from published accounts of data collection efforts at 10 U.S. programs are presented in Table 3.1. The data are notable in several respects.
Needle exchange programs attract males predominantly: the proportion of participants who are female ranges from 15 to 34 percent. However, as noted in Chapters 1 and 2, female injection drug users in general tend to show higher HIV seroincidence than their male counterparts, suggesting that the programs may not be targeting high-risk women. The sex profile of needle exchange programs is similar to that of drug abuse treatment programs and other populations used to sample injection drug users.
Needle exchange programs vary considerably in their racial/ethnic distributions. As Table 3.1 shows, the proportion of program participants who are African American ranges from 8 to 100 percent; Asian participants range from 0 to 12 percent; Hispanic participants range from 0 to 53 percent; white participants range from 0 to 70 percent; and others (primarily Native Americans) range from 0 to 28 percent. This variation across programs to some extent reflects regional differences.
The mean age at entry into needle exchange programs tends to be similar across programs, ranging from age 33 to 41.
The mean duration of injection drug use ranges from 7 to 20 years. Combined with the information available on age, these data suggest that needle exchange programs do not tend to attract recent initiates into injection drug use. A more recent report from San Francisco noted that less than 1 percent of needle exchange program participants were under age 18 (Watters et al., 1994). These data could be considered as indirect evidence that needle exchange does not encourage the initiation of injection drug use. However, considered in conjunction with the data presented in Chapter 2 on the prevalence of injection drug use by age, the overall data suggest that these programs may not be attracting the young injectors who, according to available estimates, represent a sizable portion of the injection drug user population. This is especially disconcerting in light of the findings reported in several studies that show that the risk of HIV infection is higher among younger and more recent initiates.
Before firm conclusion are drawn, it is important to note that the data presented here mostly reflect samples of program participants who agreed to be interviewed. The published descriptions of sampling procedures are incomplete, so the extent to which potential biases could have operated cannot be assessed.
When needle exchange participants were compared with nonparticipants, the participants were found to be more likely to be male and older, and less likely to be African American and to have been in drug treatment (Hagan et al., 1991; Joseph, 1989; Watters and Case, 1989).