title: The role of observational studies in assessing the impact of antiviral therapies.
abstract: During the past year many observational studies have reported on the impact of highly active antiretroviral therapy on their patient populations. Care should be taken when interpreting these findings because of possible biases due to reporting delay and loss to follow-up. The results are very encouraging, however, suggesting dramatic reductions in the incidence of AIDS and death, and resulting hospitalizations.
authors.affiliation: Department of Primary Care and Population Sciences, Royal Free and University College Medical School, London, UK.
authors.forename: Caroline A.
authors.initials: CA
authors.lastname: Sabin