Objective: To assess the impact of HIV and hepatitis C virus (HCV) infection on long-term mortality in injecting drug users (IDU).
Design: Community-based prospective cohort study.
Methods: Mortality data from follow-up in clinical sites and the Mortality Registry by December 2002 were collected for 3247 IDU who attended three centres for voluntary counselling and testing for HIV/AIDS, HCV and hepatitis B virus (HBV) in 1990–1996. Mortality rates by Poisson regression were adjusting for age, sex, duration of drug use, education, HBV and calendar period (1990–1997 and 1998–2002).
Results: Overall, 11.2% were HIV/HCV negative, 43.7% positive only for HCV and 45.1% positive for both. During 26 772 person-years of follow-up, 585 deaths were detected (2.19/100 person-years). Before 1997, HIV/HCV-positive subjects had a five-fold increase in risk of death [relative risk (RR), 5.4; 95% confidence interval (CI), 2.5–11.4] compared with those negative for both; after 1997, a three-fold increase was observed (RR, 2.7; 95% CI, 1.7–4.2). Being HCV positive/HIV negative was not associated with an increase in the risk of death either before (RR, 1.3; 95% CI, 0.6–2.9) or after (RR, 1.2; 95% CI, 0.8–1.9) 1997 compared with HCV/HIV negative. While increases in mortality were seen in those HCV/HIV negative (RR, 1.6; 95% CI, 0.7–3.7) and those only positive for HCV (RR, 1.5; 95% CI, 1.0–2.1), a 20% reduction among coinfected IDUs was observed after 1997 (interaction P = 0.033).
Conclusions: HCV/HIV coinfection has had a large impact on mortality in IDU. After 1997, mortality increased in HIV negative/HCV positive subjects and decreased in HIV positive/HCV positive.
From the aUniversity Miguel Hernández, San Juan de Alicante
bEscola Valenciana D'Estudis per la Salut (EVES), Valencia
cUniversity Hospital of Germans Trias i Pujol, Badalona, Barcelona, Spain.
Received 30 May, 2005
Revised 28 July, 2005
Accepted 18 August, 2005
Correspondence to Dr B. Lumbreras, Department of Public Health, History of Medicine and Gynaecology, Facultad de Medicina, Universidad Miguel Hernández, Carretera de Valencia Km. 8,7, 03550 San Juan de Alicante, Spain. E-mail: firstname.lastname@example.org