First-attempt success and intubation failure rates in unmatched and propensity score-matched groups by the degree of intubation difficulty
| Degree of intubation difficulty | GVL | MAC | GVL vs MAC (reference) | ||
|---|---|---|---|---|---|
| RR (95% CI) | p Value | ||||
| All patients (n=4041) | |||||
| First-attempt success rate, n (%) | Easy (n=1403) | 232 (100.0) | 1171 (100.0) | – | 0.999 |
| Slight (n=2358) | 231 (80.2) | 1709 (82.6) | 0.88 (0.69 to 1.13) | 0.323 | |
| Moderate to major (n=280) | 0 (0.0) | 0 (0.0) | – | 0.999 | |
| Intubation failure rate, n (%) | Easy (n=1403) | 4 (1.7) | 24 (2.1) | 1.00 (0.98 to 1.02) | 0.732 |
| Slight (n=2358) | 31 (10.8) | 189 (9.1) | 1.02 (0.98 to 1.06) | 0.401 | |
| Moderate to major (n=280) | 10 (50.0) | 137 (52.7) | 0.95 (0.60 to 1.49) | 0.812 | |
| Propensity score-matched patients (n=1089) | |||||
| First-attempt success rate, n (%) | Easy (n=443) | 137 (100.0) | 306 (100.0) | – | 0.999 |
| Slight (n=594) | 170 (79.8) | 335 (87.9) | 0.60 (0.41 to 0.88) | 0.008 | |
| Moderate to major (n=52) | 0 (0.0) | 0 (0.0) | – | 0.999 | |
| Intubation failure rate, n (%) | Easy (n=443) | 2 (1.5) | 7 (2.3) | 0.99 (0.97 to 1.02) | 0.535 |
| Slight (n=594) | 24 (11.3) | 18 (4.7) | 1.07 (1.02 to 1.13) | 0.008 | |
| Moderate to major (n=52) | 6 (46.2) | 21 (53.9) | 0.86 (0.47 to 1.57) | 0.619 | |
GVL, GlideScope video laryngoscope; MAC, Macintosh laryngoscope; RR, risk ratio.