title: Regional survival differences across Europe in HIV-positive people: the EuroSIDA study.
abstract: OBJECTIVE
  To analyse the survival differences between macro-regions of Europe (northern, central and southern Europe) between 1994 and early 1999, and their possible association with antiretroviral treatment differences.
  
  
  METHODS
  From September 1994 the EuroSIDA study has prospectively followed non-selected HIV-infected people from 50 clinical sites in 18 European countries (n = 7331).
  
  
  METHODS
  Cox proportional hazards models were used to compare death rates between regions and to investigate the relationship between treatment usage and regional mortality rates. Kaplan-Meier curves were used to compare survival 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 there 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 central Europe were more frequently exposed to reverse transcriptase inhibitors 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 and 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 Europe (P < 0.0001)). After adjustment for use of individual antiretroviral agents, intensity of treatment regimen, CD4 lymphocyte count, weight, haemoglobin and development of AIDS as time-dependent covariates, the differences became much smaller (risk in central Europe 13% lower than that in southern Europe (P = 0.071) and 15% lower than in northern Europe (P = 0.054).
  
  
  CONCLUSIONS
  Antiretroviral therapy has been used more aggressively in Europe in recent years, resulting in improved prognosis. In this study we observed that the HIV mortality rate in central Europe was significantly lower than 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 treatment policies and drug availability in the three regions of Europe during this time period, with central European countries, on average, having introduced more aggressive treatment strategies earlier.
authors.affiliation: Istituto Superiore di Sanita', Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Chiesi
authors.forename: A
authors.initials: A
authors.lastname: Mocroft
authors.forename: L G
authors.initials: LG
authors.lastname: Dally
authors.forename: V
authors.initials: V
authors.lastname: Miller
authors.forename: C
authors.initials: C
authors.lastname: Katlama
authors.forename: B
authors.initials: B
authors.lastname: Ledergerber
authors.forename: C
authors.initials: C
authors.lastname: Pedersen
authors.forename: A N
authors.initials: AN
authors.lastname: Phillips
authors.forename: R
authors.initials: R
authors.lastname: Arcieri
authors.forename: J D
authors.initials: JD
authors.lastname: Lundgren
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D005060:Europe; D005260:Female; D005843:Geography; D015658:HIV Infections / Q000188:drug therapy / Q000401:mortality*; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D016019:Survival Analysis
chemical_list: D019380:Anti-HIV Agents