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Table 2 Distribution of judgments by Cochrane authors and judgments reassessed in our studies by Cochrane Handbook according to the intervention (surgical/non-surgical)

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

RoB domain Re-assessment of judgments in surgical trials Re-assessment of judgments in non-surgical trials
I - random sequence generation High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
Judgment by Cochrane authors
High risk 31   1 32 (4.1%) 96.9% 233 20 80 333 (3.6%) 70.0%
Low risk   337 58 395 (50.8%) 85.3% 9 3631 916 4556 (48.9%) 79.7%
Unclear risk 4 17 330 351 (45.1%) 94.0% 28 87 4321 4436 (47.6%) 97.4%
Total N (%) 35 (4.5%) 354 (45.5%) 389 (50.0%) 778 (100.0%) 89.7% (87.4, 91.8) 270 (2.9%) 3738 (40.1%) 5317 (57.0%) 9325 (100.0%) 87.8% (87.1, 88.4)
II - allocation concealment High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
Judgment by Cochrane authors
High risk 34   9 43 (5.4%) 79.1% 353   159 512 (5.4%) 68.9%
Low risk   83 187 270 (34.2%) 30.7% 17 746 2479 3242 (34.3%) 23.0%
Unclear risk    476 476 (60.3%) 100.0% 16 10 5679 5705 (60.3%) 99.5%
Total N (%) 34 (4.3%) 83 (10.5%) 672 (85.2%) 789 (100.0%) 75.2% (72.0, 78.1) 386 (4.1%) 756 (8.0%) 8317 (87.9%) 9459 (100.0%) 71.7% (70.7, 72.6)
III + a - blinding of participants and personnel High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
Judgment by Cochrane authors  
High risk 266 1 40 307 (32.5%) 86.6% 3392 17 350 3759 (36.6%) 90.2%
Low risk 25 108 59 192 (20.3%) 56.3% 130 1578 2006 3714 (36.2%) 42.5%
Unclear risk 49 20 377 446 (47.2%) 84.5% 505 87 2201 2793 (27.2%) 78.8%
Total N (%) 340 (36.0%) 129 (13.7%) 476 (50.4%) 945 (100.0%) 79.5% (76.8, 82.0) 4027 (39.2%) 1682 (16.4%) 4557 (44.4%) 10,266 (100.0%) 69.9% (69.0, 70.7)
IV + a - blinding of outcome assessor High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
High
risk
Low
risk
Unclear
risk
Total Adequacy
(95% CI)
Judgment by Cochrane authors
High risk 174 1 44 219 (23.7%) 79.5% 2003 34 359 2396 (21.9%) 83.6%
Low risk 7 115 70 192 (20.8%) 59.9% 88 2374 2002 4464 (40.7%) 53.2%
Unclear risk 33 20 460 513 (55.5%) 89.7% 356 212 3529 4097 (37.4%) 86.1%
Total N (%) 214 (23.2%) 136 (14.7%) 574 (62.1%) 924 (100.0%) 81.1% (78.4, 83.5) 2447 (22.3%) 2620 (23.9%) 5890 (53.8%) 10,957 (100.0%) 72.2% (71.3, 73.0)
  1. aAlso includes data for joint domain of blinding of participants, personnel, and outcome assessor