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Table 2 Characteristics of included trials

From: Failure to report protocol violations in clinical trials: a threat to internal validity?

Trial Characteristics Percent (number) of Trials
Study Type  
   Individual patient RCT 76.25% (61/80)
   Factorial RCT 6.25% (5/80)
   Cluster RCT 17.5% (14/80)
Number of study arms  
   Two 83.75% (67/80)
   Three 7.5% (6/80)
   Four 8.75% (7/80)
Patient Population  
   Adults 91.25% (73/80)
   Children 6.25% (5/80)
   Infants 1.25% (1/80)
   Mixed (Adults & Children) 1.25% (1/80)
Study Intervention  
   Drug 46.25% (37/80)
   Surgery 8.75% (7/80)
   Education 10.0% (8/80)
   Other 27.5% (22/80)
   Procedure 3.75% (3/80)
   Weight loss 3.75% (3/80)
Funding Source  
   Academic 73.75% (59/80)
   Industry 26.25% (21/80)
Trial start-up meeting described 8.75% YES (7/80)
Trial run-in phase described 8.75% YES (7/80)
GCP adherence reported 6.25% YES (5/80)
Lead Investigator reports previous research experience 62.5% YES (50/80)
Trial results  
   Harm 2.5% (2/80)
   Neutral 32.5% (26/80)
   Positive 65.0% (52/80)
Management structure  
   MC, SC & others (explicit structure) 26.25% (21/80)
   MC or SC only (basic structure) 21.25% (17/80)
   Not reported 52.8% (42/80)
  1. Abbreviations: RCT - Randomised controlled trials; MC - Management Committee; SC - Steering Committee; GCP - Good Clinical Practice.