title: [AIDS incubation period in Spain before highly active antiretroviral therapy].
abstract: BACKGROUND
  To evaluate the impact of new antiretroviral therapies on progression of HIV infection, is necessary to know what was the situation before their introduction. In Spain, no data on the incubation period of AIDS from all transmission categories have been available so far.
  
  
  METHODS
  Data from 6 well established seroconverter cohorts with well documented times of HIV seroconversion (presence of an HIV negative test) identified from 1982 to current date were analysed using Kaplan-Meier methods, allowing for late entry, Cox regression and log-normal regression.
  
  
  RESULTS
  Of the 820 individuals analyzed, 80.34% were men, 57% intravenous drug users, 22% homosexual and 21% haemophiliacs. Median age at seroconversion was 25 years; median seroconversion year was 1991 and median follow-up was 4.11 years (range, 0-14.59). The incubation period of AIDS up to December 1996 was 10 years; only age at seroconversion relative risk [RR], 1.026; 95% CI, 1.005-1.047) and gender (RR, 0.58; 95% CI, 0.35-0.99) were associated with progression to AIDS with no effect of calendar year.
  
  
  CONCLUSIONS
  Progression estimates to AIDS in Spain up to 1996 are similar to other European cohorts, so is the age effect, with no calendar year effect up to that date. This shows how therapeutic interventions measured in clinical trials, which measure efficacy, do not necessarily translate in improvements at the population level, supporting the need to follow seroconverter cohorts to evaluate impact of new antiretroviral therapies.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology* / Q000517:prevention & control*; D000328:Adult; D023241:Antiretroviral Therapy, Highly Active / Q000379:methods*; D002391:Catchment Area, Health; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006679:HIV Seropositivity / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D008297:Male; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome