title: Factors associated with adherence to an end-of-study biopsy: lessons from the prostate cancer prevention trial (SWOG-Coordinated Intergroup Study S9217).
abstract: BACKGROUND
  The Prostate Cancer Prevention Trial (PCPT) was a 7-year randomized, double-blind, placebo-controlled trial of the efficacy of finasteride for the prevention of prostate cancer with a primary outcome of histologically determined prevalence of prostate cancer at the end of 7 years.
  
  
  METHODS
  A systematic modeling process using logistic regression identified factors available at year 6 that are associated with end-of-study (EOS) biopsy adherence at year 7, stratified by whether participants were ever prompted for a prostate biopsy by year 6. Final models were evaluated for discrimination. At year 6, 13,590 men were available for analysis.
  
  
  RESULTS
  Participants were more likely to have the EOS biopsy if they were adherent to study visit schedules and procedures and/or were in good health (P < 0.01). Participants at larger sites and/or sites that received retention and adherence grants were also more likely to have the EOS biopsy (P < 0.05).
  
  
  CONCLUSIONS
  Our results show good adherence to study requirements 1 year before the EOS biopsy was associated with greater odds that a participant would comply with the invasive EOS requirement.
  
  
  CONCLUSIONS
  Monitoring adherence behaviors may identify participants at risk of nonadherence to more demanding study end points. Such information could help frame adherence intervention strategies in future trials.
authors.affiliation: Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston;
authors.forename: Ellen R
authors.initials: ER
authors.lastname: Gritz
authors.affiliation: SWOG Statistical Center;
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Arnold
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center;
authors.forename: Carol M
authors.initials: CM
authors.lastname: Moinpour
authors.affiliation: Department of Basic and Social Sciences, Albany College of Pharmacy and Health Sciences, Albany, New York; allison.burton-chase@acphs.edu.
authors.forename: Allison M
authors.initials: AM
authors.lastname: Burton-Chase
authors.affiliation: SWOG Statistical Center;
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Tangen
authors.affiliation: Department of Medicine, University of Washington, Kirkland;
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Probstfield
authors.affiliation: Division of Urology, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin;
authors.forename: William A
authors.initials: WA
authors.lastname: See
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, Minnesota;
authors.forename: Michael M
authors.initials: MM
authors.lastname: Lieber
authors.affiliation: Sutter Institute for Medical Research, Sacramento;
authors.forename: Vincent
authors.initials: V
authors.lastname: Caggiano
authors.affiliation: School of Public Health, Louisiana State University Health Sciences Center, New Orleans, Louisiana;
authors.forename: Sarah
authors.initials: S
authors.lastname: Moody-Thomas
authors.affiliation: Grand Rapids Clinical Oncology Program, Grand Rapids, Michigan;
authors.forename: Connie
authors.initials: C
authors.lastname: Szczepanek
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland; and.
authors.forename: Anne
authors.initials: A
authors.lastname: Ryan
authors.affiliation: C3 Research Associates, Seattle;
authors.forename: Susie
authors.initials: S
authors.lastname: Carlin
authors.affiliation: Bothell, Washington;
authors.forename: Shannon
authors.initials: S
authors.lastname: Hill
authors.affiliation: SWOG Statistical Center;
authors.forename: Phyllis J
authors.initials: PJ
authors.lastname: Goodman
authors.affiliation: Arlington Free Clinic, Arlington, Virginia.
authors.forename: Rose Mary
authors.initials: RM
authors.lastname: Padberg
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, Rockville, Maryland; and.
authors.forename: Lori M
authors.initials: LM
authors.lastname: Minasian
authors.affiliation: Chao Family Comprehensive Cancer Center, University of California Irvine, Irvine, California;
authors.forename: Frank L
authors.initials: FL
authors.lastname: Meyskens
authors.affiliation: Cancer Therapy and Research Center, The University of Texas Health Science Center at San Antonio, San Antonio, Texas;
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
mesh_terms: D058891:5-alpha Reductase Inhibitors / Q000627:therapeutic use; D001706:Biopsy; D004311:Double-Blind Method; D018120:Finasteride / Q000627:therapeutic use; D006801:Humans; D008297:Male; D010349:Patient Compliance / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D012372:ROC Curve; D012107:Research Design
chemical_list: D058891:5-alpha Reductase Inhibitors; D018120:Finasteride