Table 2.
Polysomnographic sleep measures in participants.
| Controls a (n = 108) | Alcohol‐ dependent b (n = 73) | Cocaine‐ dependent c (n = 32) | F d ;, P | Post‐hoc comparison e | Pairwise effect sizes§ a,b; a–c; b,c | |
|---|---|---|---|---|---|---|
| Sleep continuity | ||||||
| Total sleep time, min | 363.1 ± 7.5 | 348.8 ± 8.6 | 393.4 ± 56.0 | F (2160) = 3.8, P < 0.05 | b,c** | 0.21; 0.43; 0.66 |
| Sleep efficiency, % | 80.1 ± 1.5 | 77.9 ± 1.7 | 81.4 ± 3.0 | F (2160) = 0.8, P = 0.44 | 0.16; 0.09; 0.26 | |
| Sleep latency, min | 22.4 ± 3.5 | 30.0 ± 4.0 | 20.1 ± 6.9 | F (2160) = 1.4, P = 0.24 | 0.24; 0.06; 0.31 | |
| Wakefulness after sleep onset, min | 63.3 ± 6.3 | 68.9 ± 7.2 | 74.0 ± 12.5 | F (2160) = 0.1, P = 0.93 | 0.01; 0.10; 0.09 | |
| Sleep architecture | ||||||
| Stage 1, min | 26.6 ± 1.8 | 31.0 ± 2.0 | 30.3 ± 3.5 | F (2158) = 1.3, P = 0.28 | 0.28; 0.22; 0.05 | |
| Stage 1, % | 7.0 ± 1.0 | 11.1 ± 1.1 | 9.3 ± 1.9 | F (2.158) = 2.9, P < 0.05 | a,b** | 0.48; 0.25; 0.21 |
| Stage 2, min | 236.8 ± 5.7 | 220.3 ± 6.5 | 247.9 ± 11.2 | F (2158) = 3.5, P < 0.05 | b,c*** | 0.33; 0.21; 0.55 |
| Stage 2, % | 65.2 ± 1.0 | 63.4 ± 1.1 | 63.1 ± 1.9 | F (2158) = 0.8, P = 0.45 | 0.21; 0.23; 0.03 | |
| Stage 3, min | 22.1 ± 1.8 | 9.9 ± 2.1 | 5.1 ± 3.6 | F (2158) = 11.3, P < 0.001 | a,b***; a–c*** | 0.75; 0.97; 0.29 |
| Stage 3, % | 6.2 ± 0.5 | 2.7 ± 0.6 | 1.1 ± 1.0 | F (2158) = 12.2, P < 0.001 | a,b***; a–c*** | 0.76; 10.04; 0.36 |
| Stage 4, min | 7.4 ± 1.4 | 3.0 ± 1.6 | 1.3 ± 2.7 | F (2158) = 2.5, P = 0.08 | 0.36; 0.46; 0.14 | |
| Stage 4, % | 2.0 ± 0.4 | 0.8 ± 0.4 | 0.2 ± 0.7 | F (2158) = 3.4, P < 0.05 | a,b* | 0.37; 0.53; 0.20 |
| Stage 3 + 4/SWS, min | 29.5 ± 2.8 | 12.9 ± 3.2 | 6.5 ± 5.6 | F (2158) = 8.7, P < 0.001 | a,b***; a–c** | 0.66; 0.86; 0.25 |
| Stage 3 + 4/SWS, % | 8.2 ± 0.8 | 3.5 ± 0.9 | 1.3 ± 1.5 | F (2158) = 9.9, P < 0.001 | a,b***; a–c*** | 0.68; 0.95; 0.33 |
| REM, min | 70.2 ± 3.8 | 84.7 ± 4.4 | 108.3 ± 7.6 | F (2158) = 8.5, P < 0.001 | a,b**; a–c***;b,c** | 0.43; 10.05; 0.69 |
| REM, % | 19.3 ± 0.8 | 23.7 ± 0.9 | 27.4 ± 1.6 | F (2158) = 10.2, P < 0.001 | a,b**; a–c*** | 0.61; 10.07; 0.52 |
| REM measures | ||||||
| Latency, corrected | 76.5 ± 7.3 | 63.5 ± 8.3 | 53.1 ± 14.4 | F (2158) = 1.1, P = 0.35 | 0.20; 0.34; 0.16 | |
| Density | 1.3 ± 0.1 | 1.8 ± 0.1 | 1.9 ± 0.2 | F (2158) = 5.1, P < 0.05 | a,b**; a–c* | 0.56; 0.55; 0.04 |
| Duration, 1st period | 17.4 ± 1.4 | 20.1 ± 1.5 | 22.9 ± 2.7 | F (2161) = 1.5, P = 0.23 | 0.22; 0.43; 0.23 |
d
Group omnibus test covarying for African American race, education, smoking status and Hamilton Rating Scale For Depression, 24 items (HAMD‐24);
For post‐hoc comparisons and pairwise effect sizes, labels are controls (a), alcohol dependent (b), and cocaine dependent (c).
e
multiple comparisons, adjusted using Sidak correction;
*
P < 0.10,
**
P < 0.05,
***
P < 0.001; §Cohen's d, absolute value; SWS = slow wave sleep; REM = rapid eye movement sleep. Data are presented as adjusted means ± standard error (SE).