title: Association between interactive voice response adherence and subject retention in a randomized controlled trial.
abstract: BACKGROUND
  Interactive voice response (IVR) technology uses the telephone to collect patient reports. This study examined whether IVR adherence during a year-long clinical trial was related to subject retention in the trial.
  
  
  METHODS
  As part of a randomized, double-blind, placebo-controlled study of daily multivitamin supplementation for recurrent aphthous stomatitis, 160 study participants were asked to make 1 weekly IVR call for the one-year study duration.
  
  
  RESULTS
  The 114 subjects who completed the study made 90.5% of their expected number of IVR calls, as compared to 55.7% of expected calls made by the 46 subjects who withdrew prematurely (p<0.001). Subjects who successfully completed the study were also more likely to initiate their IVR calls as compared to subjects who withdrew from the study (p<0.001). A multivariable model incorporating different adherence variables was able to successfully predict retention status of more than 80% of subjects. IVR adherence during the first few weeks of study participation was strongly predictive of subsequent retention and successful completion of this one-year study.
  
  
  CONCLUSIONS
  Subjects who withdrew prematurely had more missing data than study completers, even after accounting for period of study participation, potentially introducing bias into IVR results. Sub-optimal adherence to weekly IVR might provide an early signal of subsequent premature withdrawal in clinical trials. IVR adherence could be used as a screening tool during a trial period, to identify subjects most likely to stay on long clinical trials.
  
  
  CONCLUSIONS
  IVR adherence may be useful in anticipating retention in long-term clinical studies.
authors.affiliation: School of Dental Medicine, University of Connecticut Health Center, Farmington, CT 06030-1605, USA.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Gatehouse
authors.forename: Howard A
authors.initials: HA
authors.lastname: Tennen
authors.forename: Richard S
authors.initials: RS
authors.lastname: Feinn
authors.forename: Khamis S
authors.initials: KS
authors.lastname: Abu-Hasaballah
authors.forename: Rajesh V
authors.initials: RV
authors.lastname: Lalla
mesh_terms: D003625:Data Collection / Q000379:methods*; D019587:Dietary Supplements; D006801:Humans; D015999:Multivariate Analysis; D010349:Patient Compliance / Q000706:statistics & numerical data*; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D017010:Reminder Systems; D012107:Research Design; D013281:Stomatitis, Aphthous / Q000188:drug therapy; D013689:Telephone; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D014815:Vitamins