title: Non-compliance with the initial screening exam visit in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.
abstract: OBJECTIVE
  Identify predictors of non-compliance with first round screening exams in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial.
  
  
  METHODS
  The PLCO was conducted from 1993 to 2011 at 10 US institutions. A total of 154,897 healthy men and women ages 55-74 years were randomized. Intervention arm participants were invited to receive gender-appropriate screening exams for prostate, lung, colorectal and ovarian cancer. Using intervention-arm data (73,036 participants), non-compliance percentages for 13 covariates were calculated, as were unadjusted and adjusted odds ratios (ORs), and 95% confidence intervals. Covariates included demographic factors as well as factors specific to PLCO (e.g., method of consent, distance from screening center).
  
  
  RESULTS
  The rate of non-compliance was 11% overall but varied by screening center. Significant associations were observed for most covariates but indicated modest increases or decreases in odds. An exception was the use of a two-step consent process (consented intervention arm participants for exams after randomization) relative to a one-step process (consented all participants prior to randomization) (OR: 2.2, 95% CI: 2.0-2.5). Non-compliance percentages increased with further distance from screening centers, but ORs were not significantly different from 1.
  
  
  CONCLUSIONS
  Many factors modestly influenced compliance. Consent process was the strongest predictor of compliance.
authors.affiliation: National Cancer Institute, Division of Cancer Control and Population Sciences, 9609 Medical Center Dr, Room 4E-608, Bethesda, MD 20892-9763, USA. Electronic address: marcusp@mail.nih.gov.
authors.forename: Pamela M
authors.initials: PM
authors.lastname: Marcus
authors.affiliation: Colorado Colorectal Screening Program, University of Colorado Cancer Center, University of Colorado Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO 80045, USA. Electronic address: Sheryl.ogden@ucdenver.edu.
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Ogden
authors.affiliation: University of Utah, Department of Family and Preventive Medicine, 375 Chipeta Way, Salt Lake City, UT 84108, USA. Electronic address: Lisa.gren@hsc.utah.edu.
authors.forename: Lisa H
authors.initials: LH
authors.lastname: Gren
authors.affiliation: University of Utah, Division of Oncology, 2000 Circle of Hope, Room LL376, Salt Lake City, UT 84112, USA. Electronic address: jeff.childs@hsc.utah.edu.
authors.forename: Jeffery C
authors.initials: JC
authors.lastname: Childs
authors.affiliation: University of Colorado Anschutz Medical Campus, 13001 E 17th Pl, Aurora, CO 80045, USA. Electronic address: Shannon.pretzel@ucdenver.edu.
authors.forename: Shannon M
authors.initials: SM
authors.lastname: Pretzel
authors.affiliation: Department of Public Health Sciences, Henry Ford Health System, 1 Ford Place, Detroit, MI 48202, USA. Electronic address: llamera1@hfhs.org.
authors.forename: Lois E
authors.initials: LE
authors.lastname: Lamerato
authors.affiliation: Harvard Medical School, 180 Longwood Ave, Boston, MA 02115, USA. Electronic address: walsh@hcp.med.harvard.edu.
authors.forename: Kayo
authors.initials: K
authors.lastname: Walsh
authors.affiliation: National Cancer Institute, Division of Cancer Control and Population Sciences, 9609 Medical Center Dr, Room 4E-608, Bethesda, MD 20892-9763, USA; Drexel University School of Public Health, 1505 Race St., Philadelphia, PA 19102, USA. Electronic address: heather.rozjabek@gmail.com.
authors.forename: Heather M
authors.initials: HM
authors.lastname: Rozjabek
authors.affiliation: Information Management Systems, 6110 Executive Blvd, Rockville, MD 20852, USA. Electronic address: mabiej@imsweb.com.
authors.forename: Jerome
authors.initials: J
authors.lastname: Mabie
authors.affiliation: Information Management Systems, 6110 Executive Blvd, Rockville, MD 20852, USA. Electronic address: thomasb@imsweb.com.
authors.forename: Brett
authors.initials: B
authors.lastname: Thomas
authors.affiliation: Information Management Systems, 6110 Executive Blvd, Rockville, MD 20852, USA. Electronic address: rileyt@imsweb.com.
authors.forename: Tom
authors.initials: T
authors.lastname: Riley
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000517:prevention & control; D055088:Early Detection of Cancer / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000517:prevention & control; D008297:Male; D008403:Mass Screening / Q000523:psychology / Q000706:statistics & numerical data*; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000517:prevention & control; D010349:Patient Compliance / Q000523:psychology / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000517:prevention & control
keywords: Adherence; Cancer; Compliance; Mass screening; Randomized controlled trial as subject