title: Physicians declining patient enrollment in a critical care trial: a case study in thromboprophylaxis.
abstract: OBJECTIVE
  To analyze the frequency, rationale and determinants of attending physicians requesting that their eligible patients not be approached for participation in a thromboprophylaxis trial.
  
  
  METHODS
  Research personnel in 67 centers prospectively documented eligible non-randomized patients due to physicians declining to allow their patients to be approached.
  
  
  RESULTS
  In 67 centers, 3,764 patients were enrolled, but 1,460 eligible patients had no consent encounter. For 218 (14.9 %) of these, attending physicians requested that their patients not be approached. The most common reasons included a high risk of bleeding (31.2 %) related to fear of heparin bioaccumulation in renal failure, the presence of an epidural catheter, peri-operative status or other factors; specific preferences for thromboprophylaxis (12.4 %); morbid obesity (9.6 %); uncertain prognosis (6.4 %); general discomfort with research (3.7 %) and unclear reasons (17.0 %). Physicians were more likely to decline when approached by less experienced research personnel; considering those with[10 years of experience as the reference category, the odds ratios (OR) for physician refusals to personnel without trial experience was 10.47 [95 % confidence interval (CI) 2.19-50.02] and those with less than 10 years experience was 1.72 (95 % CI 0.61-4.84). Physicians in open rather than closed units were more likely to decline (OR 4.26; 95 % CI 1.27-14.34). Refusals decreased each year of enrollment compared to the pilot phase.
  
  
  CONCLUSIONS
  Tracking, analyzing, interpreting and reporting the rates and reasons for physicians declining to allow their patients to be approached for enrollment provides insights into clinicians' concerns and attitudes to trials. This information can encourage physician communication and education, and potentially enhance efficient recruitment.
authors.forename: D
authors.initials: D
authors.lastname: Cook
authors.forename: Y
authors.initials: Y
authors.lastname: Arabi
authors.forename: N
authors.initials: N
authors.lastname: Ferguson
authors.forename: D
authors.initials: D
authors.lastname: Heels-Ansdell
authors.forename: A
authors.initials: A
authors.lastname: Freitag
authors.forename: E
authors.initials: E
authors.lastname: McDonald
authors.forename: F
authors.initials: F
authors.lastname: Clarke
authors.forename: S
authors.initials: S
authors.lastname: Keenan
authors.forename: G
authors.initials: G
authors.lastname: Pagliarello
authors.forename: W
authors.initials: W
authors.lastname: Plaxton
authors.forename: M
authors.initials: M
authors.lastname: Herridge
authors.forename: T
authors.initials: T
authors.lastname: Karachi
authors.forename: S
authors.initials: S
authors.lastname: Vallance
authors.forename: J
authors.initials: J
authors.lastname: Cade
authors.forename: T
authors.initials: T
authors.lastname: Crozier
authors.forename: S
authors.initials: S
authors.lastname: Alves da Silva
authors.forename: R
authors.initials: R
authors.lastname: Costa Filho
authors.forename: N
authors.initials: N
authors.lastname: Brandao
authors.forename: I
authors.initials: I
authors.lastname: Watpool
authors.forename: T
authors.initials: T
authors.lastname: McArdle
authors.forename: G
authors.initials: G
authors.lastname: Hollinger
authors.forename: Y
authors.initials: Y
authors.lastname: Mandourah
authors.forename: M
authors.initials: M
authors.lastname: Al-Hazmi
authors.forename: N
authors.initials: N
authors.lastname: Zytaruk
authors.forename: N K J
authors.initials: NK
authors.lastname: Adhikari
mesh_terms: D003422:Critical Care / Q000523:psychology*; D017985:Dalteparin / Q000009:adverse effects / Q000627:therapeutic use; D004311:Double-Blind Method; D005343:Fibrinolytic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D006493:Heparin / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D007258:Informed Consent / Q000523:psychology*; D007362:Intensive Care Units; D010358:Patient Participation; D018579:Patient Selection; D010820:Physicians / Q000523:psychology*; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies; D045808:Refusal to Participate / Q000523:psychology*; D013927:Thrombosis / Q000517:prevention & control*
chemical_list: D005343:Fibrinolytic Agents; D006493:Heparin; D017985:Dalteparin
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