سرعت انتشار مصرف اكتساسي در بين دوستان فرد مصرف كننده

Diffusion rate of ecsasy use in peer group of an ecstasy user

Introduction: Syntetic drugs has emerged recently as a new form of drugs of abuse. Modeling drug use spread from drug users to other persons, as in communicable diseases, has been utilized in drug abuse researches for more than three decades, and using this model can be very useful for study on drug in their nascence in a community. Methods: This is a historical cohort study on diffusion of ecstasy use in the peer group of an ecstasy user. The study participants consist of persons acknowledged their ecstasy use, in treatment facilities or other ways. As index cases, we asked them to mention the first time of ecstasy use in their peers and define the ecstasy use status of them by the time of interview. Results: Thirty index cases named 156 peers, among them 43 (27.6%) have started ecstasy use after them, and 25 (16.0%) have not tried it yet, also 43 friends (27.6%) had tried this substance before the index cases and another 43 ones (27.6%) have tried ecstasy for the first time simultaneously with the index cases. Since there were 68 peers who had not used ecstasy after the time that index cases had tried this drug, and therefore, they were at risk of first ecstasy use, the secondary attack rate of this disease was 0.63 (95% Cl: 0.43-0.93) and the basic reproductive rate was 1.59 (95% Cl: 0.98-2.58). The median ecstasy free survival was 15 months (95% CI: 8-22 months) and the highest risk of transmission was in the first 10 months after an index case used first ecstasy. Factors that affect the survival time were index case age, peer age, absolute age difference between index and his/her peer, and using alcohol by the index case. Discussion: This is the first study on diffusion of ecstasy use in the peer group of a user, modeling it as a communicable disease and using survival models. It shows that ecstasy use is a moderately highly infectious disease and we can say, with some caution, that its use is increasing.