Table 4.
Sample characteristics of the included studies.
| Study | N | Sample | Percentage females | Mean age (years) | Country |
|---|---|---|---|---|---|
| Wing et al. (19) | 603 | Students | 42 | 21 | China |
| Spanos et al. (20) | 1,798 | Students | 54 | 20 | Canada |
| Fukuda et al. (21) | 86 | Students | 73 | 21 | Canada |
| Fukuda et al. (21) | 149 | Students | 41 | 19 | Japan |
| Cheyne et al. (22) | 870 | Students | 56 | 20 | Canada |
| Wing et al. (23) | 158 | General population | 58 | 80 | China |
| Buzzi and Cirignotta (24) | 264 | Mix | Unknown | Unknown | Italy |
| Cheyne and Girard (25) | 383 | Mix | 73 | 31 | Mix |
| Abrams et al. (26) | 263 | Mix students/general community | 73 | 22 | Canada |
| Ramsawh et al. (27) | 72 | Mix students/general community | 74 | 25 | USA |
| Solomonova et al. (28) | 193 | Persons with sleep paralysis, of whom 85% were psychiatric patients | 66 | 32 | Canada |
| Jiménez-Genchi et al. (29) | 385 | School children/adolescents | 67 | 16 | Mexico |
| Paradis et al. (30) | 208 | Students | 81 | 22 | USA |
| Young et al. (31) | 747 | Hmong immigrants | 38 | 40 | USA |