Aims: To determine the prevalence of anaemia among HIV-positive and -negative drug users, estimate the incidence of anaemia among HIV-positive drug users and study risk factors for prevalent anaemia with emphasis on HIV infection, gender and drug use behaviour.
Design, setting and participants: Cross-sectional study among HIV-positive and HIV-negative drug users (n = 360) and a longitudinal study among HIV-positive drug users (n = 175, 860 visits) participating in a cohort study of drug users in Amsterdam.
Measurements: Self-reported data on socio-demographics, drug use behaviour and zidovudine and protease inhibitor therapy on regular cohort visits. Laboratory determinations of haemoglobin concentration, CD4(+)-cell counts and HIV-1 RNA.
Findings: The prevalence of anaemia was 21.1% among participating drug users according to the WHO definition. The incidence of anaemia in HIV-positive individuals was 33.0/100 person-years. The main risk factor for anaemia was high frequency of injecting drugs. A Quetelet body mass index < or = 20 and female gender were also positively and significantly related to anaemia in the cross-sectional study. In the longitudinal study among HIV-positive drug users progression of HIV infection indicated by low CD4(+)-cell count and AIDS diagnosis were predictive of anaemia.
Conclusion: The results indicate that drug users in the Amsterdam cohort study have a high prevalence of anaemia, which can be explained mainly by high frequency of injecting drugs and HIV infection progression. Reduction or cessation of injecting drug use should reduce anaemia.