Time Course of Fatigue and Other Symptoms in the Study Population
| Measure [Reference Score for General Population]a | Baseline (n=642) | 1 Month (n=562) | 4 Months (n=562) | 8 Months (n=524) | 12 Months (n=568) |
|---|---|---|---|---|---|
| CIS = Checklist Individual Strength; SF-36 = 36-Item Short Form Health Survey; 4DSQ = Four-Dimensional Symptoms Questionnaire; SCL-90=Symptom Checklist 90. | |||||
| a Reference scores based on 53 healthy subjects for the CIS10 and a random sample of 1,742 people from the general population for the SF-36.17 | |||||
| b Percentages based on available data for each time point. | |||||
| c On the 4DSQ, scores are elevated if they exceed 10 for distress, 2 for depression, 7 for anxiety, and 10 for somatization. | |||||
| d On the sleep scale of the SCL-90, scores are elevated if they exceed 5 for women and 4 for men. | |||||
| Fatigue, CIS score | |||||
| Severity score, mean (SD) [17] | 45.8 (8.4) | 38.3 (11.2) | 35.4 (12.3) | 33.5 (13.4) | 32.0 (13.5) |
| Score >34, No. (%) (range, 8–56) | 578 (90) | 369 (66) | 324 (57) | 257 (49) | 259 (46) |
| Total score, mean (SD) [42] (range, 20–140) | 96 (20) | 84 (24) | 78 (26) | 75 (28) | 71 (28) |
| Health status, SF-36 score, mean (SD) | |||||
| Physical functioning [83] | 74 (23) | 78 (22) | 81 (20) | 82 (20) | 83 (20) |
| Physical role functioning [76] | 35 (36) | 51 (40) | 59 (40) | 62 (40) | 66 (40) |
| Emotional role functioning [82] | 64 (41) | 72 (39) | 75 (37) | 76 (38) | 77 (37) |
| Social functioning [84] | 60 (22) | 68 (22) | 71 (23) | 73 (22) | 76 (23) |
| Bodily pain [75] | 72 (24) | 77 (24) | 78 (24) | 78 (25) | 79 (24) |
| Mental health [77] | 63 (18) | 68 (18) | 68 (18) | 69 (18) | 71 (18) |
| Vitality [69] | 36 (16) | 46 (18) | 50 (19) | 53 (21) | 56 (21) |
| General health [71] | 60 (19) | 60 (20) | 61 (19) | 62 (21) | 63 (21) |
| Absent from work, No. (%)b | 238 (38) | 184 (33) | 138 (25) | 118 (23) | 109 (20) |
| Refrained from other activities, No. (%)b | 352 (56) | 281 (50) | 219 (40) | 212 (41) | 205 (38) |
| Psychological symptoms, 4DSQ score, mean (SD); % with elevated scorec | |||||
| Distress | 13.3 (7.4); 61 | – | – | – | 8.7 (7.0); 35 |
| Somatization | 11.0 (6.2); 48 | – | – | – | 7.9 (6.1); 30 |
| Depression | 1.7 (2.6); 24 | – | – | – | 1.0 (2.1); 15 |
| Anxiety | 2.5 (3.6); 10 | – | – | – | 1.7 (3.1); 5.3 |
| Sleep, SCL-90 score, mean (SD); % with score above meand | 7.0 (3.1); 65 | – | – | – | 6.4 (2.7); 58 |