Table 2 POGO scores and MCL grades in the head-flat and head-elevated positions
|  | Head-flat position (n = 64) | Head-elevated position (n = 64) | Difference (95% CI) | P value |
|---|---|---|---|---|
POGO score, % | 37.5 ± 24 | 59.4 ± 23.8 | 21.9 (17.1 to 26.7) | < 0.0001 |
MCL grade | ||||
 Easy: Grade 1/2a | 11/17 (43.7) | 27/28 (85.9) | 42.2 (30 to 54.4) | < 0.0001 |
 Restricted: Grade 2b/3a | 28/8 (56.3) | 7/2 (14.1) |  | – |
 Difficult: Grade 3b/4 | 0/0 (0) | 0/0 (0) |  | – |