title: [The Cohort of the Spanish HIV Research Network (CoRIS) and its associated biobank; organizational issues, main findings and losses to follow-up].
abstract: BACKGROUND
  This article describes the development of the Cohort of the Spanish Research Network (CoRIS), its methodological and organizational aspects, the demographic and clinical characteristics of the subjects enrolled and quantifies the losses to follow-up and associated factors.
  
  
  METHODS
  Multicentre cohort of HIV-positive naïve subjects recruited in 28 sites of Spain from 2004-onwards. Missing and inconsistent data were submitted to internal quality controls and the datasets were externally audited. Multiple logistic regression models were used.
  
  
  RESULTS
  As of October 2009, 5,514 subjects had been recruited, representing 11,708 person-years with a median follow-up time of 1.81 years. Most are men (78.8%), infected by sexual transmission (46.1% men who have sex with men and 35.2% heterosexual persons) and Spanish (69.7%). During follow-up 64.5% have started Antiretroviral Therapy (ART) and 201 deaths have occurred. New HIV diagnoses accounted for 80.7% of the sample. Some 52% of subjects had at least one baseline sample in the BioBank while naïve to ART. Losses to follow-up (18.9%) were more frequent in younger people, in injecting drug users, in persons of non-Spanish origin, in persons with primary or lower educational level, and in those with a CD4 count over 350 cells/mm(3) at time of recruitment.
  
  
  CONCLUSIONS
  The implementation of CoRIS has been successful; the cohort has wide representation at national level, is actively recruiting new members and blood samples, and has excellent data quality. Losses to follow-up are of similar magnitude to other cohort studies, as are the factors associated with them.
authors.affiliation: Red de Investigación en Sida, Centro Nacional de Epidemiología, Instituto de Salud Carlos III, Madrid, España. psobrino@isciii.es
authors.forename: Paz
authors.initials: P
authors.lastname: Sobrino-Vegas
authors.forename: Félix
authors.initials: F
authors.lastname: Gutiérrez
authors.forename: Juan
authors.initials: J
authors.lastname: Berenguer
authors.forename: Pablo
authors.initials: P
authors.lastname: Labarga
authors.forename: Federico
authors.initials: F
authors.lastname: García
authors.forename: Belén
authors.initials: B
authors.lastname: Alejos-Ferreras
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Muñoz
authors.forename: Santiago
authors.initials: S
authors.lastname: Moreno
authors.forename: Julia
authors.initials: J
authors.lastname: del Amo
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology; D019380:Anti-HIV Agents / Q000627:therapeutic use; D018070:Biological Specimen Banks / Q000458:organization & administration / Q000706:statistics & numerical data; D001793:Blood Preservation; D015897:Comorbidity; D015925:Cryopreservation; D004247:DNA / Q000032:analysis; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology* / Q000635:transmission; D006801:Humans; D007258:Informed Consent; D007391:International Cooperation; D008297:Male; D015337:Multicenter Studies as Topic; D010352:Patient Dropouts / Q000706:statistics & numerical data; D011446:Prospective Studies; D012725:Sexual Behavior; D013030:Spain / Q000453:epidemiology; D015819:Substance Abuse, Intravenous
chemical_list: D019380:Anti-HIV Agents; D004247:DNA