RESUMEN
BACKGROUND: Prospective follow-up of heroin users is known to be difficult due to their unstable lifestyle, and high follow-up rates have usually demanded major tracking efforts. In Sweden, mobile telephones are commonly used by heavy drug users for drug trading. OBJECTIVES: This methodology study aims to examine the efficacy of mobile telephone contact for prospective follow-up interviews with injecting heroin users recruited at the syringe exchange program of Malmö, Sweden. METHODS: Seventy-eight heroin users with mobile telephone numbers were included. Subjects reported using heroin for 28 days of the previous 30 days, and only 8% reported they had recently been engaged in work or studies. Clients were contacted between 15 and 21 times over 2 years, with each contact attempt generally involving two telephone calls on consecutive days. RESULTS: During follow-up, 68% of subjects had been successfully contacted for at least one follow-up interview (on average 6.9 interviews), and 25% of follow-up attempts were successful. In 23% of the sample (n=18), at least 50% of follow-up attempts were successful, and these subjects tended to be older (p=.05) and more likely to be female (p=.07), whereas follow-up rates were unrelated to baseline heroin use. CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE: Despite limited effort, and despite the severe situation of intravenous heroin users, mobile telephone contact can be used with heavy drug users in the present setting.