title: Factors associated with the first antiretroviral therapy modification in older HIV-1 positive patients.
abstract: BACKGROUND
  Rates of first antiretroviral therapy (cART) modifications are high in most observational studies. The age-related differences in treatment duration and characteristics of first cART modifications remain underinvestigated. With increasing proportion of older patients in HIV population it is important to better understand age-related treatment effects.
  
  
  METHODS
  Patients were included into this analysis, if being cART naïve at the first visit at the clinic. Follow-up time was measured from the first visit date until first cART modification or 28 February 2013. First cART modification was defined as any change in the third drug component i.e. protease inhibitor (PI), non-nucleoside reverse transcriptase inhibitor (NNRTI), integrase inhibitor or fusion inhibitor. Cox proportional hazard models were used to identify factors related to first cART modification in three age groups: <30, 30-50 and >50.
  
  
  RESULTS
  In total 2027 patients with 14,965 person-years of follow-up (PYFU) were included. The oldest group included 136 patients with 1901, middle group 1202 with 8416 PYFU and youngest group consisted of 689 patients with 4648 PYFU. Median follow-up time was 5.8 (IQR 3.4-9.4) years, median time on first cART was 4.4 (IQR 2.1-8.5) years. 72.4 % of patients started PI-based and 26.1 % NNRTI-based regimen. In total 1268 (62.5 %) patients had cART modification (non-adherence 30.8 %, toxicity 29.6 %). Durability of first cART was the best in patients over 50 y.o. (log-rank test, p = 0.001). Factors associated with discontinuation in this group were late presentation (HR 0.45, [95 % CI 0.23-0.90], p = 0.02) and PI use (HR 2.17, [95 % CI 1.18-4.0], p = 0.01).
  
  
  CONCLUSIONS
  Rates of first cART modifications or discontinuation were comparable in all groups; however older patients were significantly longer on first cART regimen.
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland ; Department for Adult's Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Justyna D
authors.initials: JD
authors.lastname: Kowalska
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kubicka
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Siwak
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Pulik
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Firląg-Burkacka
authors.affiliation: Hospital for Infectious Diseases, HIV Out-Patient Clinic, Warsaw, Poland ; Department for Adult's Infectious Diseases, Medical University of Warsaw, Warsaw, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Horban
mesh_terms: D000328:Adult; D000367:Age Factors; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D057915:Drug Substitution / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D019380:Anti-HIV Agents
keywords: Aging; Antiretroviral therapy; Late presenters; Pharmacovigilance; Toxicity