Regional survival differences across Europe in HIV-positive people: the EuroSIDA study

Objectives: To analyse the survival differences between macro-regions of Eu rope (northern, central and southern Europe) between 1994 and early 1999, a nd their possible association with antiretroviral treatment differences. Design: From September 1994 the EuroSIDA study has prospectively followed n onselected HIV-infected people from 50 clinical sites in 18 European countr ies (n = 7331). Methods: Cox proportional hazards models were used to compare death rates b etween regions and to investigate the relationship between treatment usage and regional mortality rates. Kaplan-Meier curves were used to compare surv ival from the first CD4 lymphocyte count of < 200 x 10(6)/l or < 50 x 10(6) /l. Results: At the time of analysis, the median follow-up was 21 months and th ere was a total of 1544 deaths. In people with a CD4+ cell count that fell below 200 or 50 x 10(6)/l those from central Europe had a better prognosis compared with those from the two other regions (P < 0.05). Patients from ce ntral Europe were more frequently exposed to reverse transcriptase inhibito rs and protease inhibitors compared with patients from other regions (P < 0 .001). There was a significant difference in risk of death between regions after adjustment for baseline differences in demography, presence of AIDS a nd level of immunodeficiency (risk of death in central Europe was 37% lower than that in southern Europe (P < 0.0001) and 33% lower than in northern E urope (P < 0.0001)). After adjustment for use of individual antiretroviral agents, intensity of treatment regimen, CD4 lymphocyte count, weight, haemo globin and development of AIDS as time-dependent covariates, the difference s became much smaller (risk in central Europe 13% lower than that in southe rn Europe (P = 0.071) and 15% lower than in northern Europe (P = 0.054). Conclusion: Antiretroviral therapy has been used more aggressively in Europ e in recent years, resulting in improved prognosis. In this study we observ ed that the HIV mortality rate in central Europe was significantly lower th an those in northern and southern Europe in the period 1994 to early 1999. This finding appears to be due to the effect on survival of different treat ment policies and drug availability in the three regions of Europe during t his time period, with central European countries, on average, having introd uced more aggressive treatment strategies earlier. (C) 1999 Lippincott Will iams & Wilkins.