Table 3.
Polysomnography (PSG) Data of North Korean Refugees and South Koreans
| PSG Parameter | North Korean Refugees (n=32) | South Korean (n=39) | t | P value |
|---|---|---|---|---|
| Mean ± SD | Mean ± SD | |||
| Total sleep time (min) | 403.5±72.7 | 409.5±45.5 | −0.43 | 0.67 |
| Sleep efficiency (%) | 89.6±11.9 | 86.6±8.6 | 1.22 | 0.23 |
| WASO (min)** | 26.0±24.5 | 46.9±33.1 | −3.06 | 0.003 |
| N1 (%)* | 11.1±7.1 | 15.1±8.9 | −2.05 | 0.04 |
| N2 (%)* | 58.2±7.4 | 54.0±7.6 | 2.29 | 0.03 |
| N3 (%) | 9.3±7.9 | 10.7±9.4 | −0.70 | 0.49 |
| REM (%) | 21.4±5.4 | 25.2±28.4 | −0.74 | 0.46 |
| Sleep latency (min) | 16.5±37.5 | 15.7±17.0 | 0.11 | 0.91 |
| SWS latency (min) | 27.2±21.8 | 35.0±47.3 | −0.84 | 0.41 |
| REM latency (min) | 108.5±65.2 | 113.8±49.5 | −0.38 | 0.70 |
| Total arousal index (min) | 2.5±2.5 | 3.2±4.3 | −0.90 | 0.37 |
Notes: *p value<0.05. **p value<0.01.
Abbreviations: WASO, wake after sleep onset; SWS, slow wave sleep; REM, rapid eye movement.