Reasons for selecting an initial route of heroin administration and for subsequent transitions during a severe HIV epidemic.

AIM: To identify the most important reasons for selecting a particular route of heroin administration and for subsequent transitions during a period of epidemic HIV transmission. To study temporal trends in these reasons.
DESIGN: Cross-sectional survey. PARTICIPANTS: Nine hundred heroin users in three Spanish cities: 305 in Seville, 297 in Madrid and 298 in Barcelona. MEASUREMENTS: A separate analysis was made of the reasons for five types of behaviour: (a) selecting injection as the initial usual route of heroin administration (URHA); (b) changing the URHA to injection; (c) never having injected drugs; (d) selecting the smoked or sniffed route as the initial URHA; and (e) changing the URHA to a non-injected route. Subjects were invited to evaluate the importance of each reason included in a closed list. Spontaneously self-perceived reasons were also explored in an open-ended question for each of the five types of behaviour studied.
FINDINGS: The primary reason selected for each type of behaviour was: (a) pressure of the social environment; (b) belief that injection is a more efficient route than smoking or sniffing heroin; (c) concern about health consequences (especially fears of HIV and overdose), and fear of blood or of sticking a needle into one's veins; (d), pressure of the social environment and (e) concern about health consequences and vein problems. For women, having a sexual partner who injected heroin played a decisive role in initiating or changing to injection. Few people spontaneously mentioned market conditions for purchasing heroin as an important reason for any behaviour, nor did many mention risk of overdose as reasons for (c) or (d).
CONCLUSIONS: These findings should be considered when designing interventions aimed at preventing initiation of injecting or facilitating the transition to non-injected routes.