title: Prospectively screening for eligible patients was inaccurate in predicting patient recruitment of orthopedic randomized trials.
abstract: OBJECTIVE
  To compare the accuracy of estimates of potential recruitment from a prospective 8-week screening study compared with a retrospective chart review across sites participating in two fracture management trials.
  
  
  METHODS
  During the planning phase of two large, multicenter, randomized controlled fracture management trials, 74 clinical sites provided estimates of the annual recruitment rate both retrospectively (based on chart reviews) and prospectively. The prospective estimate was generated by screening, for 8 weeks, all incoming patients for eligibility in the concerning trial, without actually enrolling any patient. We compared these prospective and retrospective estimates with one another (for 74 sites in the two trials) and with actual 1-year recruitment rates in the definitive trial (for nine sites in one trial).
  
  
  RESULTS
  There was a median difference of four patients (interquartile range: -14 to 18 patients; P=0.89) between a center's prospective estimate and its retrospective estimate. Both predictions were overestimations of recruitment in the definitive trial; only 31% (95% confidence interval [CI]: 28, 35) of retrospectively estimated patients, and 31% (95% CI: 27, 35) of prospectively estimated patients were recruited in the definitive trials.
  
  
  CONCLUSIONS
  Compared with relatively simple chart reviews, prospectively screening for eligible patients at clinical sites, which is associated with substantial costs, did not result in more accurate predictions of accrual in large, multicenter, randomized controlled trials.
authors.affiliation: Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Ontario L8L 2X2, Canada. baukekooistra@hotmail.com
authors.forename: Bauke W
authors.initials: BW
authors.lastname: Kooistra
authors.forename: Bernadette G
authors.initials: BG
authors.lastname: Dijkman
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.forename: Sheila
authors.initials: S
authors.lastname: Sprague
authors.forename: Paul
authors.initials: P
authors.lastname: Tornetta
authors.forename: Mohit
authors.initials: M
authors.lastname: Bhandari
mesh_terms: D005260:Female; D006620:Hip Fractures / Q000601:surgery*; D006801:Humans; D008297:Male; D009985:Orthopedics; D018579:Patient Selection; D011446:Prospective Studies; D012189:Retrospective Studies