title: Analysis of Factors Affecting Successful Clinical Trial Enrollment in the Context of Three Prospective, Randomized, Controlled Trials.
abstract: Challenges can arise when attempting to maximize patient enrollment in clinical trials. There have been limited studies focusing on the barriers to enrollment and the efficacy of alternative study design to improve accrual. We analyzed barriers to clinical trial enrollment, particularly the influence of timing, in context of three prospective, randomized oncology trials where one arm was considered more aggressive than the other.
  
  
  
  From June 2011 to March 2015, patients who were enrolled on 3 prospective institutional protocols (an oligometastatic non-small cell lung cancer [NSCLC] trial and 2 proton vs intensity modulated radiation therapy trials in NSCLC and esophageal cancer) were screened for protocol eligibility. Eligible candidates were approached about trial participation, and patient characteristics (age, sex, T/N categorization) were recorded along with details surrounding trial presentation (appointment number). Fisher's exact test, Student's t tests, and multivariate analysis were performed to assess differences between enrolled and refusal patients.
  
  
  
  A total of 309 eligible patients were approached about trial enrollment. The enrollment success rate during this time span was 52% (n=160 patients). Enrolled patients were more likely to be presented trial information at an earlier appointment (oligometastatic protocol: 5 vs 3 appointments [P<.001]; NSCLC protocol: 4 vs 3 appointments [P=.0018]; esophageal protocol: 3 vs 2 appointments [P=.0086]). No other factors or patient characteristics significantly affected enrollment success rate.
  
  
  
  Improvement in enrollment rates for randomized control trials is possible, even in difficult accrual settings. Earlier presentation of trial information to patients is the most influential factor for success and may help overcome accrual barriers without compromising trial design.
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Logan
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Chad
authors.initials: C
authors.lastname: Tang
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Zhongxing
authors.initials: Z
authors.lastname: Liao
authors.affiliation: Department of Biostatistics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: J Jack
authors.initials: JJ
authors.lastname: Lee
authors.affiliation: Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: John V
authors.initials: JV
authors.lastname: Heymach
authors.affiliation: Department of Surgical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Swisher
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: James W
authors.initials: JW
authors.lastname: Welsh
authors.affiliation: Department of Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas. Electronic address: dgomez@mdanderson.org.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gomez
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D004608:Eligibility Determination / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007258:Informed Consent / Q000523:psychology / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000523:psychology* / Q000532:radiotherapy*; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010342:Patient Acceptance of Health Care / Q000523:psychology* / Q000706:statistics & numerical data; D018579:Patient Selection; D015995:Prevalence; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic / Q000379:methods / Q000523:psychology*; D017678:Sex Distribution; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology