Table 5: GRADE level of evidence and certainty. Intravascular balloon occlusion

compared with not using intravascular occlusion balloon to reduce intraoperative bleeding.

Certainty assessment

N of patients

Effect

Certainty

Importance

N of

studies

Study

design

Risk

of bias

Inconsistency

Indirectness

Imprecision

Other

considerations

Intravascular

occlusion

balloon

Not

intravascular

occlusion

balloon

Relative

(95% CI)

Absolute

(95% CI)

Ioscovich

A

2023

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

10 cases 11 controls

OR 1.58

(−2.53 to −0.63)

⨁⨁⨁◯

Moderate

Important

0.0%

0 fewer

per 1,000

(from 0 fewer

to 0 fewer)

Hao Z

2016

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Very strong

association

18 cases 23 controls

OR −3.98

(−5.03 to −2.93)

⨁⨁⨁⨁

High

Important

0.0%

0 fewer

per 1,000

(from 0 fewer

to 0 fewer)

Zeng C

2017

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Very strong

association

48 cases 38 controls

OR −0.56

(−0.99 to −0.13)

⨁⨁⨁⨁

High

Important

0.0%

0 fewer

per 1,000

(from 0 fewer

to 0 fewer)

Huo F

2021

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Very strong

association

17/33

(51.5%)

16/33

(48.5%)

OR 0.12

(−0.54 to 0.79)

383 fewer

per 1,000

(from 1,000 fewer

to 58 fewer)

⨁⨁⨁⨁

High

Important

Papillon−

Smith J

2020

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

47/79

(59.5%)

32/79

(40.5%)

OR −0.76

(−1.22 to −0.30)

1,000 fewer

per 1,000

(from 1,000 fewer

to 662 fewer)

⨁⨁⨁◯

Moderate

No

important

Ye Y

2023

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

278/364

(76.4%)

86/364

(23.6%)

OR −2.30

(−2.60 to −2.01)

1,000 fewer

per 1,000

(from 1,000 fewer

to 1,000 fewer)

⨁⨁⨁◯

Moderate

Important

Wu Q

2016

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Very strong

association

230/268

(85.8%)

38/268

(14.2%)

OR −8.36

(−9.15 to −7.57)

1,000 more

per 1,000

(from 1,000 more

to 1,000 more)

⨁⨁⨁⨁

High

Important

Peng W

2020

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

252/586

(43.0%)

296/586

(50.5%)

OR 0.46

(0.29 to 0.63)

186 fewer

per 1,000

(from 277 fewer

to 114 fewer)

⨁⨁⨁◯

Moderate

Important

Zhao X

2016

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

23 cases 34 controls

OR −18.28

(−21.68 to −14.89)

⨁⨁⨁◯

Moderate

No

important

0.0%

0 fewer

per 1,000

(from 0 fewer

to 0 fewer)

Duan X

2018

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

22/45

(48.9%)

23/45

(51.1%)

OR −4.26

(−5.31 to −3.21)

778 more

per 1,000

(from 709 more

to 913 more)

⨁⨁⨁◯

Moderate

Important

Wang Y

2020

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Serious

Strong

association

600/623

(96.3%)

23/623

(3.7%)

OR −3.62

(−4.08 to −3.16)

198 fewer

per 1,000

(from 222 fewer

to 175 fewer)

⨁⨁◯◯

Low

No

important

Peng Y

2020

Non-

randomised

studies

Not

serious

Not

serious

Not

serious

Not

serious

Strong

association

48/104

(46.2%)

56/104

(53.8%)

OR 0.37

(−0.02 to 0.76)

237 fewer

per 1,000

(from 562 fewer

to 68 fewer)

⨁⨁⨁◯

Moderate

Important