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Table 2 Comparison of outcome results.

From: Treatment effect bias in randomised controlled trials using surrogate outcomes: a preliminary cohort study analysis

  Surrogate Trials (N=138) N (%) Final Trials (N=132) N (%) P-value a
Study outcome b    0.006 c
Positive 49 (36) 41 (31)  
Negative 5 (4) 4 (3)  
Neutral 32 (23) 65 (49)  
Risk of bias    
Statement of ITT 95 (69) 106 (80) 0.031
Automated sequence generation 82 (59) 93 (70) 0.058
Allocation concealment 96 (70) 97 (63) 0.476
Blinding/Placebo 72 (52) 60 (45) 0.27
  1. aChi-square test, unless otherwise specified.
  2. b‘positive’: treatment group superior to control (P≤0.05); ‘negative’, control group superior to treatment (P≤0.05); ‘neutral’, treatment and control indifferent, P>0.05).
  3. cFisher’s exact test. Multiple-interventions trials are excluded from this comparison.