title: Retention in a public healthcare system with free access to treatment:  a Danish nationwide HIV cohort study.
abstract: OBJECTIVE
  We aimed to assess retention of HIV-infected individuals in the Danish healthcare system over a 15-year period.
  
  
  METHODS
  Loss to follow-up (LTFU) was defined as 365 days without contact to the HIV care system. Data were obtained from the nationwide Danish HIV Cohort study, The Danish National Hospital Registry and The Danish Civil Registration System. Incidence rates, risk factors for LTFU and return to care and mortality rate ratios (MRRs) were estimated using Poisson regression analyses.
  
  
  RESULTS
  We included 4745 HIV patients who were followed for 36,692 person-years. Patients were retained in care 95.0% of person-years under observation, increasing to 98.1% after initiation of highly active antiretroviral treatment (HAART). The overall incidence rate/100 person-years for first episode of LTFU was 2.6 [95% confidence interval (CI) 2.5-2.8] and was significantly lower after initiation of HAART [1.2 (95% CI 1.0-1.3)]. Five years after LTFU the probability of return to care was 0.87 (95% CI 0.84-0.90). The risk of death was significantly increased after LTFU [MRR 1.9 (95% CI 1.6-2.6)] and 6 months or less after return to care [MRR 10.9 (95% CI 5.9-19.9)].
  
  
  CONCLUSIONS
  Retention in care of Danish HIV patients is high, especially after initiation of HAART. Absence from HIV care is associated with increased mortality. We conclude that high rates of retention can be achieved in a healthcare system with free access to treatment and is associated with a favorable outcome.
authors.affiliation: Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark. mhelleberg@sund.ku.dk
authors.forename: Marie
authors.initials: M
authors.lastname: Helleberg
authors.forename: Frederik N
authors.initials: FN
authors.lastname: Engsig
authors.forename: Gitte
authors.initials: G
authors.lastname: Kronborg
authors.forename: Carsten S
authors.initials: CS
authors.lastname: Larsen
authors.forename: Gitte
authors.initials: G
authors.lastname: Pedersen
authors.forename: Court
authors.initials: C
authors.lastname: Pedersen
authors.forename: Jan
authors.initials: J
authors.lastname: Gerstoft
authors.forename: Niels
authors.initials: N
authors.lastname: Obel
mesh_terms: D000328:Adult; D003695:Delivery of Health Care / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000188:drug therapy* / Q000401:mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D012307:Risk Factors; D013222:State Medicine / Q000706:statistics & numerical data