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Table 3 Differentiation of justifications (causes) for risk judgments with tests and interpretations

From: Adequacy of risk of bias assessment in surgical vs non-surgical trials in Cochrane reviews: a methodological study

  Risk judgment justification basis Intervention
Domain I (random sequence generation) Categorization of supporting comments Non-surgical Surgical
Randomization not described 5317 (57.0%) 389 (50.0%)
Random number table 815 (8.7%) 68 (8.7%)
Computerized randomization 2597 (27.8%) 253 (32.5%)
Mechanical randomization 326 (3.5%) 33 (4.2%)
Inappropriate randomization 270 (2.9%) 35 (4.5%)
Domain II (allocation concealment) Type of allocation concealment Non-surgical Surgical
Central allocation 506 (5.3%) 32 (4.1%)
Incomplete SNOSE 1117 (11.8%) 147 (18.6%)
Not described/unclear 7200 (76.1%) 525 (66.5%)
Open / predictable allocation 386 (4.1%) 34 (4.3%)
SNOSE 250 (2.6%) 51 (6.5%)
Domain III + a (blinding of participants and personnel) Blinding achieved Non-surgical Surgical
Achieved 1239 (12.1%) 38 (4.0%)
Not done or not possible 4318 (42.1%) 414 (43.8%)
Probably done 4709 (45.9%) 493 (52.2%)
Outcome influenced by lack of blinding Non-surgical Surgical
Influenced 472 (4.6%) 21 (2.2%)
Unknown 9340 (91.0%) 832 (88.0%)
Not influenced 454 (4.4%) 92 (9.7%)
Domain IV + a (blinding of outcome assessors) Blinding achieved Non-surgical Surgical
Achieved 1722 (15.7%) 84 (9.1%)
Probably done 6695 (61.1%) 609 (65.9%)
Not done or not possible 2540 (23.2%) 231 (25.0%)
Outcome influenced by lack of blinding Non-surgical Surgical
Influenced 919 (8.4%) 31 (3.4%)
Unknown 9045 (82.5%) 839 (90.8%)
Not influenced 993 (9.1%) 54 (5.8%)
  1. aAlso includes data for joint domain of blinding of participants, personnel and outcome assessor; SNOSE = sequentially numbered sealed opaque envelopes