Table 1.
Demographic and pain variables in chronic pain patients sleeping normally or having sleep problems.
| Sleeping normally | Sleep problems | P | |
|---|---|---|---|
| n | 61 | 199 | |
| Age: mean (SD) | 46.7 (14.7) | 46.5 (12.7) | 0.89 |
| Female: n (%) | 42 (68.9) | 134 (67.3) | 0.83 |
| Education years: mean (SD) | 13.7 (3.7) | 13.7 (3.8) | 0.98 |
| Living alone: n (%) | 9 (14.8) | 56 (28.1) | 0.04 |
| Currently working or studying: n (%) | 36 (59.0) | 75 (38.1) | 0.004 |
| Pain intensity: mean (SD) | 4.2 (2.2) | 6.3 (1.5) | <0.001 |
| Number of pain sites: median (IQR) | 2.0 (4) | 4.0 (5) | <0.001 |
| Pain duration > 2 y: n (%) | 36 (61.0) | 153 (78.1) | 0.01 |
| PASS-20: mean (SD) | |||
| Cognitive anxiety (0-25) | 10.8 (6.9) | 15.4 (5.1) | <0.001 |
| Escape/avoidance (0-25) | 9.7 (6.5) | 13.4 (4.9) | <0.001 |
| Fear of pain (0-25) | 6.7 (5.4) | 10.5 (5.7) | <0.001 |
| Physiological anxiety (0-25) | 4.7 (5.0) | 9.7 (5.3) | <0.001 |
| n* | 58 | 196 | |
| Pain diagnoses: n (%) | |||
| Neuropathic pain | 15 (25.9) | 57 (29.1) | 0.63 |
| Back pain | 6 (10.3) | 52 (26.5) | 0.01 |
| Other musculoskeletal pain | 9 (15.5) | 49 (25.0) | 0.13 |
| Facial pain | 37 (63.8) | 39 (19.9) | <0.001 |
| Headache | 4 (6.9) | 13 (6.6) | 1.000 |
| Fibromyalgia | 2 (3.4) | 22 (11.2) | 0.08 |
| Abdominal pain | 0 (0.0) | 6 (3.1) | 0.34 |
| CRPS | 1 (1.7) | 11 (5.6) | 0.31 |
| Phantom limb pain | 0 (0.0) | 1 (0.5) | 1.000 |
| Chronic pain syndrome | 2 (3.4) | 5 (2.6) | 0.66 |
*
Differences in n with respect to original categorization are due to missing data. Bold indicates P values <0.05.
CRPS, complex regional pain syndrome; IQR, interquartile range; PASS-20, Pain Anxiety Symptoms Scale-20.