| All participants (N = 253) | Centers A to D (N = 238) | Center E (N = 15) | p-value |
---|---|---|---|---|
Post-graduate year (PGY) | ||||
 PGY-1 | 74 (29) | 71 (30) | 3 (20) | 0.49 |
 PGY-2 | 73 (29) | 67 (28) | 6 (40) |  |
 PGY-3 | 65 (26) | 62 (26) | 3 (20) |  |
 PGY-4 | 15 (6) | 14 (6) | 1 (7) |  |
 PGY-5 | 16 (6) | 14 (6) | 2 (13) |  |
Gender | ||||
 Males | 132 (52) | 122 (51) | 10 (67) | 0.43 |
 Females | 109 (43) | 104 (44) | 5 (33) |  |
Number of ultrasound-guided paracenteses performed | ||||
 None | 23 (9) | 22 (9) | 1 (7) | 0.01 |
 1–2 | 52 (21) | 51 (21) | 1 (7) |  |
 3–5 | 73 (29) | 72 (30) | 1 (7) |  |
 6–9 | 43 (17) | 39 (16) | 4 (27) |  |
 10 or more | 52 (21) | 44 (18) | 8 (53) |  |
Number of ultrasound-guided thoracenteses performed | ||||
 None | 41 (16) | 41 (17) | 0 | 0.01 |
 1–2 | 74 (29) | 71 (30) | 3 (20) |  |
 3–5 | 66 (26) | 63 (26) | 3 (20) |  |
 6–9 | 36 (14) | 29 (12) | 7 (47) |  |
 10 or more | 25 (10) | 23 (10) | 2 (13) |  |
Number of ultrasound-guided central line insertions performed | ||||
 None | 35 (14) | 34 (14) | 1 (7) | 0.17 |
 1–2 | 27 (11) | 26 (11) | 1 (7) |  |
 3–5 | 39 (15) | 39 (16) | 0 |  |
 6–9 | 42 (17) | 37 (16) | 5 (33) |  |
 10 or more | 99 (39) | 91 (38) | 8 (53) |  |
Number of ultrasound-guided peripheral intravenous catheterizations performed | ||||
 None | 173 (68) | 167 (70) | 6 (40) | 0.004 |
 1–2 | 26 (10) | 20 (8) | 6 (40) |  |
 3–5 | 26 (10) | 24 (10) | 2 (13) |  |
 6–9 | 5 (2) | 4 (2) | 1 (7) |  |
 10 or more | 11 (4) | 11 (5) | 0 |  |
How often learners wanted to perform an US-guided procedure but was not able to do so due to lack of supervisor/teacher (and not because of lack of equipment):b Mean ± standard deviation | 2.1 ± 0.8 | 2.1 ± 0.8 | 1.7 ± 0.6 | 0.04 |