Table 2.
Standard PSG/MSLT measures
| Subjectively sleepy controls (0), N = 48 | NT1 (1), N = 46 | NT2 (2), N = 12 | IH (3), N = 18 | ANOVA, p value | 0 vs 1, p value | 0 vs 2, p value | 0 vs 3, p value | 1 vs 2, p value | 2 vs 3, p value | 1 vs 3, p value | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| TST (hours) | 8.8 (1.3) | 9.4 (1.1) | 9.7 (1.1) | 10.4 (2.5) | .003 | NS | NS | p ~ 0 | NS | NS | .010 |
| SOL (min) | 34.6 (40) | 9.9 (13.4) | 21 (19.6) | 28.1 (28.4) | ~0 | .006 | NS | NS | NS | NS | NS |
| AI | 8.9 (3.1) | 13 (5.5) | 9.8 (2.8) | 7.9 (3) | ~0 | ~0 | NS | NS | .023 | NS | ~0 |
| SE | 86.1 (9.1) | 89.1 (6.5) | 92.8 (5.9) | 91.6 (5.8) | .017 | .045 | .019 | .045 | NS | NS | NS |
| WASO (min) | 39.8 (33) | 56.5 (40.2) | 21 (16.3) | 26.6 (25.3) | .007 | .021 | NS | NS | .003 | NS | .022 |
| N1 % | 5.8 (4.2) | 10.2 (7) | 6.6 (4.3) | 4.6 (4.1) | ~0 | .01 | NS | NS | NS | NS | ~0 |
| N2 % | 46.5 (10.6) | 41.8 (10) | 43.6 (8.1) | 54.8 (5.8) | .003 | .026 | NS | .05 | NS | .007 | ~0 |
| N3 % | 23.8 (10.1) | 22 (9.2) | 21.3 (9.4) | 14.3 (6.5) | .054 | NS | NS | .009 | NS | NS | NS |
| REM % | 24 (6.3) | 26 (7.3) | 28.6 (6.2) | 26.4 (3.8) | NS | NS | .014 | NS | NS | NS | NS |
| REM sleep onset latency (min) | 114.9 (47.3) | 54 (68.7) | 76 (56.1) | 109.7 (46) | ~0 | ~0 | .033 | NS | NS | .041 | ~0 |
Subjectively sleepy controls refer to subjectively sleepy patients who presented with self-reported daytime sleepiness but had normal sleep study testing. P values represent group differences; ANOVA statistic used with continuous data and chi-square testing for categorical data. P values reflect analysis adjusted for demographic effects (age, sex, race). TST, total sleep time; SOL, sleep onset latency; AI, arousal index; SE, sleep efficiency; WASO, wake after sleep onset; sleep stages percentages are relative to PSG record duration. ~0 denotes p value <.0005.