| 2.1 Difficulty levels defined by original studies |
12 |
1059 |
Risk Ratio (M‐H, Random, 95% CI) |
1.27 [1.08, 1.49] |
| 2.1.1 Difficult |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.1.2 No restriction by intravenous access difficulty level |
2 |
389 |
Risk Ratio (M‐H, Random, 95% CI) |
1.05 [0.92, 1.19] |
| 2.2 Difficulty levels defined by the success rate with landmark method |
12 |
1059 |
Risk Ratio (M‐H, Random, 95% CI) |
1.27 [1.08, 1.49] |
| 2.2.1 Difficult |
8 |
588 |
Risk Ratio (M‐H, Random, 95% CI) |
1.53 [1.12, 2.08] |
| 2.2.2 Moderate |
3 |
436 |
Risk Ratio (M‐H, Random, 95% CI) |
1.07 [0.94, 1.23] |
| 2.2.3 Easy |
1 |
35 |
Risk Ratio (M‐H, Random, 95% CI) |
1.00 [0.90, 1.11] |
| 2.3 Operators could not see and palpate a target vein |
4 |
294 |
Risk Ratio (M‐H, Random, 95% CI) |
1.53 [0.98, 2.41] |
| 2.4 Participants had a history of difficult intravenous access |
6 |
390 |
Risk Ratio (M‐H, Random, 95% CI) |
1.66 [0.97, 2.86] |
| 2.5 Participants had multiple failed attempts |
5 |
279 |
Risk Ratio (M‐H, Random, 95% CI) |
1.53 [0.93, 2.51] |
| 2.6 Operators finished any training program for ultrasound‐guided peripheral venous cannulation |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.6.1 Finished |
9 |
610 |
Risk Ratio (M‐H, Random, 95% CI) |
1.35 [1.06, 1.71] |
| 2.6.2 Not specified |
1 |
60 |
Risk Ratio (M‐H, Random, 95% CI) |
1.91 [1.13, 3.23] |
| 2.7 Operators had any clinical experience with ultrasound‐guided peripheral intravenous cannulation |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.7.1 Had any clinical experience |
5 |
315 |
Risk Ratio (M‐H, Random, 95% CI) |
1.15 [0.91, 1.44] |
| 2.7.2 Did not have any clinical experience |
3 |
235 |
Risk Ratio (M‐H, Random, 95% CI) |
1.46 [1.18, 1.79] |
| 2.7.3 Not specified |
2 |
120 |
Risk Ratio (M‐H, Random, 95% CI) |
2.08 [1.41, 3.09] |
| 2.8 Operators finished any training program for ultrasound‐guided peripheral venous cannulation and had any clinical experience |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.8.1 Finished any training program for ultrasound‐guided peripheral venous cannulation and had any clinical experience |
5 |
315 |
Risk Ratio (M‐H, Random, 95% CI) |
1.15 [0.91, 1.44] |
| 2.8.2 Not finished any training program for ultrasound‐guided peripheral venous cannulation or no clinical experience |
3 |
235 |
Risk Ratio (M‐H, Random, 95% CI) |
1.46 [1.18, 1.79] |
| 2.8.3 Not specified |
2 |
120 |
Risk Ratio (M‐H, Random, 95% CI) |
2.08 [1.41, 3.09] |
| 2.9 Types of operators |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.9.1 Nurses |
8 |
551 |
Risk Ratio (M‐H, Random, 95% CI) |
1.37 [1.05, 1.78] |
| 2.9.2 Physicians |
2 |
119 |
Risk Ratio (M‐H, Random, 95% CI) |
1.72 [0.22, 13.47] |
| 2.10 Setting |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.10.1 Emergency department |
6 |
401 |
Risk Ratio (M‐H, Random, 95% CI) |
1.57 [1.05, 2.36] |
| 2.10.2 ICU |
3 |
234 |
Risk Ratio (M‐H, Random, 95% CI) |
1.36 [0.86, 2.15] |
| 2.10.3 Operating room |
1 |
35 |
Risk Ratio (M‐H, Random, 95% CI) |
1.00 [0.90, 1.11] |
| 2.11 Year of publication |
10 |
670 |
Risk Ratio (M‐H, Random, 95% CI) |
1.40 [1.10, 1.77] |
| 2.11.1 Publication year: 1999 ~ 2008 |
2 |
95 |
Risk Ratio (M‐H, Random, 95% CI) |
1.70 [0.10, 29.24] |
| 2.11.2 Publication year: 2009 ~ |
8 |
575 |
Risk Ratio (M‐H, Random, 95% CI) |
1.36 [1.08, 1.71] |
| 2.12 Dynamic guidance or static guidance |
1 |
300 |
Risk Ratio (M‐H, Random, 95% CI) |
1.10 [1.03, 1.18] |
| 2.12.1 Dynamic |
1 |
150 |
Risk Ratio (M‐H, Random, 95% CI) |
1.10 [1.00, 1.21] |
| 2.12.2 Static |
1 |
150 |
Risk Ratio (M‐H, Random, 95% CI) |
1.10 [1.00, 1.21] |
