Table 2.
Overall sleep stage durations by dosage group. Mean (and standard deviation) for each sleep stage are presented in minutes, along with sleep efficiency and number of awakenings; model-fit group difference estimates (and standard error) are presented, as are T values and p values for the dosage group comparisons. Left: Placebo vs. Low Dose (0.3 mg) Melatonin; Right: Placebo vs. High Dose (5.0 mg) Melatonin.
| Overall | Overall | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Placebo mean (std dev) | Low Dose mean (std dev) | Estimate (std err) | T value (df=266) | P-value | Placebo | High Dose | Estimate (std err) | T value (df=272) | P-value | |
| Sleep Efficiency (%) | 71.57 (7.15) | 74.65 (6.31) | 3.05 (1.81) | 1.69 | 0.0927 | 69.42 (9.04) | 75.68 (5.68) | 6.24 (1.81) | 3.44 | 0.0007 |
| Stage 1 (min) | 33.94 (16.52) | 38.59 (23.76) | 4.61 (1.59) | 2.9 | 0.0041 | 36.75 (21.31) | 40.22 (19.41) | 3.37 (1.49) | 2.27 | 0.0242 |
| Stage 2 (min) | 138.23 (18.22) | 152.20 (21.17) | 14.01 (4.68) | 3 | 0.003 | 119.81 (24.96) | 146.25 (21.05) | 26.50 (4.21) | 6.29 | <0.0001 |
| Stage SWS (min) | 47.04 (23.75) | 41.50 (26.85) | −5.56 (1.78) | −3.13 | 0.002 | 54.28 (22.60) | 44.59 (21.99) | −9.69 (1.98) | −4.9 | <0.0001 |
| Stage NREM (min) | 219.21 (23.48) | 232.29 (27.39) | 13.02 (5.36) | 2.43 | 0.0159 | 210.84 (25.56) | 231.05 (16.82) | 20.17 (5.14) | 3.92 | 0.0001 |
| Stage REM (min) | 66.37 (14.03) | 65.76 (14.29) | −0.61 (2.83) | −0.22 | 0.829 | 66.47 (14.93) | 71.22 (11.59) | 4.73 (2.93) | 1.61 | 0.1078 |
| TST (min) | 285.58 (28.41) | 298.06 (25.10) | 12.37 (7.22) | 1.71 | 0.0878 | 277.30 (36.10) | 302.27 (22.77) | 24.91 (7.25) | 3.44 | 0.0007 |
| Stage Wake (min) | 113.50 (28.75) | 100.58 (25.26) | −12.84 (7.16) | −1.79 | 0.074 | 122.12 (36.10) | 97.15 (22.76) | −24.91 (7.26) | −3.43 | 0.0007 |
| SoL (min) | 20.53 (12.15) | 17.37 (9.37) | −3.20 (3.93) | −0.81 | 0.4172 | 17.84 (9.51) | 16.03 (9.58) | −1.78 (2.31) | −0.77 | 0.4419 |
| Number of awakenings | 23.81 (9.04) | 24.53 (10.49) | 0.03 (0.02) | 1.18 | 0.2385 | 22.43 (9.67) | 24.45 (13.30) | 0.09 (0.02) | 3.49 | 0.0006 |
| Average duration of awakenings | 6.03 (2.68) | 5.19 (2.09) | 0.17 (0.10) | 2.76a | 0.0968 | 7.00 (3.38) | 4.93 (2.97) | 0.33 (0.10) | 10.18a | 0.0014 |
std dev=standard deviation; std err=standard error; df=degrees of freedom; min=minutes, SWS=slow wave sleep, NREM=non REM sleep, REM=rapid eye movement sleep, TST=total sleep time, SoL=sleep onset latency.
a
=chi-square statistic, df=1