title: Participant retention in clinical trials of candidate HIV vaccines.
abstract: OBJECTIVE
  : To determine predictors of loss to follow-up (LTFU) in trials of candidate HIV vaccines.
  
  
  METHODS
  : Data were obtained from trials of candidate preventive HIV vaccines conducted by the AIDS Vaccine Evaluation Group (AVEG) and HIV Network for Prevention Trials (HIVNET) that enrolled HIV-negative volunteers. Analytic models included multiple logistic regression and generalized estimating equations.
  
  
  RESULTS
  : Of 3033 volunteers enrolled in 48 trials, 282 (9.3%) persons did not complete follow-up. In univariate analyses, age, trial duration, and number of immunizations were associated with LTFU. In a multivariate logistic model, age (per year) (adjusted odds ratio [AOR] = 0.96, 95% confidence interval [CI]: 0.95, 0.98) and study duration (per month) (AOR = 1.04, 95% CI: 1.01, 1.08) remained significantly associated with LTFU.
  
  
  CONCLUSIONS
  : Younger age and increasing trial duration predicted LTFU. Limiting enrollment in trials of novel products to those less than 40 years of age may exclude participants shown to have improved retention. Trials should be designed to last only as long as required to address the scientific question. Retention efforts in future trials should especially address younger persons.
authors: HIV Vaccine Trials Network Core Operations, Seattle, WA, USA. debruyng@hivsa.com
authors: Guy
authors: G
authors: de Bruyn
authors: Michael G
authors: MG
authors: Hudgens
authors: Patrick S
authors: PS
authors: Sullivan
authors: Ann C
authors: AC
authors: Duerr
mesh_terms: D016915:AIDS Vaccines; D000328:Adult; D000367:Age Factors; D017321:Clinical Trials, Phase I as Topic / Q000706:statistics & numerical data*; D017322:Clinical Trials, Phase II as Topic / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D016915:AIDS Vaccines