Table 3. Inter- and intragroup variance in repeated subjective and objective measures.
| Sublingual zolpidem 5 mg (n=34) | Oral zolpidem 10 mg (n=33) | Within subjects (p-values) | ||||
|---|---|---|---|---|---|---|
| Baseline | Third phase | Baseline | Third phase | Factor | xGroup | |
| Sleep diaries | ||||||
| Sleep onset latency, minutes | 78 (57-99) | 25 (17-34) | 51 (27-75) | 31 (20-41) | < 0.001 | 0.031 |
| Nights with MOTN awakenings, % | 75 (62-88) | 36 (20-53) | 87 (71-100) | 43 (24-62) | < 0.001 | 0.707 |
| Rescue dose nights*, % | 22 (11-33) | 15 (5-26) | 20 (7-33) | 10 (-3-22) | 0.223 | 0.799 |
| Total sleep time, hours | 4.8 (4.3-5.3) | 6.4 (5.9-6.9) | 4.5 (3.9-5.0) | 5.7 (5.2-6.3) | < 0.001 | 0.390 |
| Sleep efficiency, % | 62 (55-70) | 81 (75-86) | 60 (52-69) | 76 (70-83) | < 0.001 | 0.096 |
| Questionnaire scores | ||||||
| ISI | 17 (15-18) | 6 (4-8) | 18 (16-19) | 8 (6-10) | < 0.001 | 0.470 |
| PSQI | 11 (10-12) | 8 (7-10) | 12 (11-13) | 10 (9-11) | < 0.001 | 0.608 |
| KSS, 30 minutes† | 5 (4-5) | 5 (4-6) | 5 (4-6) | 5 (5-6) | 0.088 | 0.605 |
| KSS, 2 hours† | 4 (3-4) | 3 (3-4) | 4 (3-4) | 4 (3-4) | 0.178 | 0.233 |
| PSG parameters | ||||||
| Sleep-onset latency | 27 (17-38) | 17 (9-24) | 18 (8-28) | 24 (16-31) | 0.502 | 0.031 |
| Wake after sleep onset | 89 (39-139) | 46 (34-58) | 67 (17-118) | 52 (39-64) | 0.102 | 0.440 |
| Total sleep time | 326 (306-347) | 352 (334-369) | 333 (312-353) | 350 (332-368) | 0.001 | 0.518 |
| Sleep efficiency | 80 (75-84) | 83 (79-87) | 80 (75-84) | 82 (78-87) | 0.048 | 0.824 |
| Arousal index | 12 (10-15) | 13 (11-16) | 16 (13-18) | 14 (12-17) | 0.828 | 0.165 |
| REM sleep | 20 (18-22) | 19 (17-20) | 19 (17-21) | 19 (17-20) | 0.440 | 0.504 |
| Slow wave sleep | 22 (19-25) | 24 (21-27) | 22 (19-25) | 23 (21-26) | 0.057 | 0.708 |
| AHI | 2.1 (0.6-3.6) | 3.1 (1.7-4.5) | 3.6 (2.1-5.1) | 3.9 (2.5-5.3) | 0.183 | 0.448 |
| SaO2min | 91 (89-92) | 89 (88-90) | 89 (88-91) | 88 (87-90) | 0.002 | 0.591 |
| PVT parameters† | ||||||
| Sleepiness, 30 minutes | 5 (4-6) | 6 (5-7) | 5 (4-6) | 6 (5-7) | 0.043 | 0.869 |
| Sleepiness, 2 hours | 3 (2-4) | 3 (2-4) | 4 (4-5) | 4 (3-5) | 0.171 | 0.328 |
| Total hits, 30 minutes | 92 (91-94) | 90 (85-95) | 93 (92-95) | 91 (85-96) | 0.169 | 0.885 |
| Total hits, 2 hours | 90 (86-94) | 94 (90-98) | 95 (91-99) | 92 (88-96) | 0.850 | 0.097 |
| Lapses, 30 minutes | 16 (10-22) | 9 (5-12) | 5 (0-11) | 7 (3-11) | 0.151 | 0.054 |
| Lapses, 2 hours | 7 (3-12) | 4 (2-7) | 4 (0-9) | 4 (2-7) | 0.279 | 0.363 |
| Reaction time, 30 minutes | 412 (359-464) | 368 (320-416) | 340 (287-394) | 346 (297-395) | 0.285 | 0.162 |
| Reaction time, 2 hours | 336 (301-372) | 309 (273-346) | 300 (263-336) | 313 (276-350) | 0.625 | 0.151 |
Data presented as mean (95% confidence interval), unless otherwise specified.
95%CI = 95% confidence interval; AHI = apnea-and-hypopnea index; ISI = Insomnia Severity Index; KSS = Karolinska Sleepiness Scale; MOTN awakenings = middle-of-the-night awakenings; PSG = polysomnography; PSQI = Pittsburgh Sleep Quality Index; PVT = Psychomotor Vigilance Test; REM = rapid-eye-movement; SaO2min = minimum oxyhemoglobin saturation.
Last observation carried forward (LOCF) = Missing values for discontinued participants were replaced by baseline or the last observed value. Within-subject statistics are presented for treatment effect alone (Factor) and interaction effect with the treatment group (x Group).
Bold font indicates statistical significance.
At baseline, rescue dose nights refers to the percentage of nights a rescue dose was taken until the visit at week 6, i.e. half of the treatment period. It was used as a covariate in the PSG and PVT models to control for residual effects.
Subjective sleepiness and psychomotor performance were measured twice, 30 minutes and 2 hours after awakening from PSG.