3.1 Difficulty levels defined by original studies |
7 |
1410 |
Mean Difference (IV, Random, 95% CI) |
0.05 [‐0.42, 0.51] |
3.1.1 Difficult |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.1.2 Moderate |
1 |
401 |
Mean Difference (IV, Random, 95% CI) |
0.10 [‐0.47, 0.67] |
3.1.3 Easy |
1 |
596 |
Mean Difference (IV, Random, 95% CI) |
0.60 [0.17, 1.03] |
3.1.4 No restriction by intravenous access difficulty level |
1 |
90 |
Mean Difference (IV, Random, 95% CI) |
‐0.10 [‐0.85, 0.65] |
3.2 Difficulty levels defined by the success rate with landmark method |
7 |
1410 |
Mean Difference (IV, Random, 95% CI) |
0.05 [‐0.42, 0.51] |
3.2.1 Difficult |
3 |
305 |
Mean Difference (IV, Random, 95% CI) |
‐0.49 [‐1.48, 0.49] |
3.2.2 Moderate |
2 |
491 |
Mean Difference (IV, Random, 95% CI) |
0.03 [‐0.43, 0.48] |
3.2.3 Easy |
1 |
596 |
Mean Difference (IV, Random, 95% CI) |
0.60 [0.17, 1.03] |
3.2.4 No results on both first‐pass and overall success of cannulation |
1 |
18 |
Mean Difference (IV, Random, 95% CI) |
0.90 [‐0.52, 2.32] |
3.3 Operators finished any training program for ultrasound‐guided peripheral venous cannulation |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.3.1 Finished |
3 |
305 |
Mean Difference (IV, Random, 95% CI) |
‐0.49 [‐1.48, 0.49] |
3.3.2 Not specified |
1 |
18 |
Mean Difference (IV, Random, 95% CI) |
0.90 [‐0.52, 2.32] |
3.4 Types of operators |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.4.1 Nurses |
3 |
131 |
Mean Difference (IV, Random, 95% CI) |
‐0.36 [‐1.68, 0.95] |
3.4.2 Technicians |
1 |
192 |
Mean Difference (IV, Random, 95% CI) |
0.20 [‐0.61, 1.01] |
3.5 Setting |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.5.1 Emergency department |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.6 Year of publication |
4 |
323 |
Mean Difference (IV, Random, 95% CI) |
‐0.20 [‐1.13, 0.72] |
3.6.1 Publication year: 1999 ~ 2008 |
1 |
18 |
Mean Difference (IV, Random, 95% CI) |
0.90 [‐0.52, 2.32] |
3.6.2 Publication year: 2009 ~ |
3 |
305 |
Mean Difference (IV, Random, 95% CI) |
‐0.49 [‐1.48, 0.49] |