title: [Cohort studies and their contribution to the study of HIV infection: main characteristics and limitations].
abstract: In this paper, we provide a definition of cohort studies and reviews the main types of cohort studies used in the context of HIV infection. We discuss how the main sources of selection biases in cohort studies are those derived from the lack of observation of the event that determines the origin and/or of the event of interest due to losses to follow-up or development of a competing event, and how this bias must be appropriately taken into account following specific epidemiological methods. Although cohort studies play an essential role in the study of HIV infection, they are logistically complex and require considerable resources. Therefore, strategic planning on the quality and quantity of the information collected must always be accompanied by a resource allocation plan.
authors.affiliation: Centro Nacional de Epidemiología, Instituto de Salud Carlos III, Madrid, España. ijarrin@isciii.es
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Jarrín
authors.forename: Francisco
authors.initials: F
authors.lastname: Bolúmar
authors.forename: Julia
authors.initials: J
authors.lastname: del Amo
mesh_terms: D015982:Bias; D015331:Cohort Studies; D018450:Disease Progression; D015658:HIV Infections / Q000175:diagnosis*; D006801:Humans