Table 1.
Comparing subgroups of individuals with chronic fatigue syndrome (CFS) defined by age and illness duration on mean functioning and symptomatology (N = 652).
| Variables | Younger (<55), Illness Duration <10 Years | Younger (<55), Illness Duration >10 Years | Older (>55), Illness Duration <10 Years | Older (>55), Illness Duration >10 Years | Sig. |
|---|---|---|---|---|---|
| (n = 334) | (n = 107) | (n = 76) | (n = 135) | ||
| M (SD) | M (SD) | M (SD) | M (SD) | ||
| SF-36 Subscales | |||||
| Vitality | 17.9 (15.5) a | 13.2 (12.3) a | 14.6 (15.4) | 18.8 (16.4) | * |
| Physical Functioning | 38.5 (23.1) | 30.6 (22.8) | 31.1 (22.9) | 37.3 (21.4) | * |
| Role Physical | 5.7 (17.0) | 5.8 (17.5) | 6.4 (11.8) | 4.6 (16.2) | - |
| Bodily Pain | 40.8 (25.5) | 40.0 (25.8) | 38.2 (22.8) | 44.2 (21.0) | - |
| General Health | 27.2 (16.6) | 24.1 (16.3) | 27.2 (16.3) | 30.4 (17.4) | - |
| Social Functioning | 26.9 (23.1) | 22.7 (23.2) | 24.7 (24.8) | 31.7 (24.8) | - |
| Mental Health | 67.5 (18.7) a | 67.7 (17.5) b | 64.6 (19.7) c | 73.8 (16.7) a,b,c | ** |
| Role Emotional | 72.9 (40.4) | 73.8 (41.8) | 64.4 (43.3) | 74.4 (37.7) | - |
| Domain Composites | |||||
| Fatigue/PEM | 50.7 (22.8) | 53.7 (23.4) | 52.2 (24.4) | 45.3 (24.9) | - |
| Sleep Dysfunction | 34.8 (19.4) | 36.8 (18.7) | 34.8 (17.2) | 30.2 (18.1) | - |
| Pain | 28.7 (18.4) | 30.8 (20.3) | 29.8 (16.4) | 23.7 (14.5) | - |
| Neurocognitive | 70.3 (40.2) | 63.1 (32.3) | 77.0 (37.3) | 62.7 (36.7) | - |
| Autonomic | 23.9 (17.7) | 27.9 (20.8) a | 23.9 (15.6) | 18.3 (15.4) a | * |
| Neuroendocrine | 29.5 (22.8) a | 31.2 (20.4) | 27.5 (15.0) | 21.7 (20.8) a | * |
| Immune | 23.4 (16.3) | 25.6 (16.3) a | 21.4 (13.4) | 18.1 (14.1) a | * |
* p < 0.05, ** p < 0.01. Similar letters (a, b and c) across rows indicate significant differences in post-hoc analyses.