title: Recruitment challenges in clinical research including cancer patients and their caregivers. A randomized controlled trial study and lessons learned.
abstract: BACKGROUND
  To test seven different strategies for recruitment in a randomized controlled trial, to report documented response data from each strategy, and to discuss recruitment challenges.
  
  
  METHODS
  We used 5 opt-in (potential participants have to do something active to contact or be contacted by the researcher) and 2 opt-out (potential participants have the option to decline being contacted about a study) recruitment strategies from February 2013 until July 2014 to contact 1562 cancer patient candidates for participation in a randomized controlled trial. For each of these cancer patients a caregiver was also invited to take part in the study.
  
  
  RESULTS
  Of the 1562 candidates, 22.6 % were ineligible on initial contact, 56.7 % declined to participate on initial contact, and 8.9 % agreed orally to participate but did not complete the enrollment. The 2 opt-out strategies, on-site recruitment and routine care letters recruitment, yielded the highest number of recruited participants with 79 dyads and 58 dyads respectively, constituting 42.7 % and 31.4 % of the total number of enrolled candidates. The 5 opt-in recruitment approaches yielded 49 dyads for the study. Almost half of these dyads were recruited using the approach termed "relying on providers at the hospital."
  
  
  CONCLUSIONS
  In this study, opt-out recruitment strategies appeared to be the most effective.
  
  
  BACKGROUND
  Registration number NCT01867723 , registered February 2012.
authors.affiliation: Center for Shared Decision Making and Collaborative Care Research, Oslo University Hospital, Oslo, Norway. karin.sygna@rr-research.no.
authors.forename: Karin
authors.initials: K
authors.lastname: Sygna
authors.affiliation: Center for Shared Decision Making and Collaborative Care Research, Oslo University Hospital, Oslo, Norway. sjh@ous-hf.no.|Division of Cancer, Surgery and Transplantation, Department of Oncology, Oslo University Hospital, Radium Hospital, Oslo, Norway. sjh@ous-hf.no.|Oslo and Akershus University College of Applied Sciences, Faculty of Health Science, Oslo, Norway. sjh@ous-hf.no.
authors.forename: Safora
authors.initials: S
authors.lastname: Johansen
authors.affiliation: Center for Shared Decision Making and Collaborative Care Research, Oslo University Hospital, Oslo, Norway. cornelia.ruland@rr-research.no.|Department of Medicine, University of Oslo, Oslo, Norway. cornelia.ruland@rr-research.no.
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: Ruland
mesh_terms: D000329:Advertising / Q000379:methods*; D017028:Caregivers / Q000523:psychology*; D002755:Choice Behavior; D015709:Correspondence as Topic; D004608:Eligibility Determination; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D033181:Information Dissemination; D008402:Mass Media; D009369:Neoplasms / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D009664:Norway; D010174:Pamphlets; D010342:Patient Acceptance of Health Care; D018579:Patient Selection; D035842:Research Subjects / Q000523:psychology*; D018401:Sample Size; D061108:Social Media