Table 2.
Independent samples t tests between nightmare occurrence and control group (i.e. not experiencing nightmare) for all variables
| Variable | Nightmares (n = 381) Mean (SD) |
Control group (n = 465) Mean (SD) |
t | ES (d) | df | p |
|---|---|---|---|---|---|---|
| Age | 41.4 (16.1) | 46.8 (15.3) | 5.4 | 0.3 | 844 | <0.001*** |
| Negative affect | 48.1 (16.5) | 39.4 (11.9) | −8.9 | 0.6 | 844 | <0.001*** |
| Worry | 52.8 (13.9) | 44.4 (14.1) | −8.3 | 0.6 | 844 | <0.001*** |
| Depersonalisation | 46.4 (16.6) | 38.4 (12.4) | −8.0 | 0.5 | 844 | <0.001*** |
| Hallucination | 15.3 (8.1) | 12.1 (5.2) | −3.6 | 0.5 | 844 | <0.001*** |
| Paranoia | 31.2 (17.6) | 23.7 (12.3) | −7.5 | 0.5 | 844 | <0.001*** |
| Alcohol use | 20.0 (9.2) | 20.1 (8.5) | 0.2 | <0.1 | 844 | 0.832 |
| Activity level | 15.5 (4.3) | 15.6 (4.1) | 0.1 | <0.1 | 844 | 0.806 |
| Sleep duration | 7.6 (1.3) | 7.3 (1.2) | −0.3 | 0.2 | 844 | 0.002** |
| PTSD | 1.3 (1.5) | 0.7 (1.1) | −0.6 | 0.7 | 844 | <0.001*** |
| Life events | 223.6 (151.5) | 163.1 (122.3) | −60.5 | 0.4 | 844 | <0.001*** |
* p < 0.05, ** p < 0.01, *** p < 0.001