Table 1
Prevalence, incidence, and characteristics of CFS-like cases in the Maastricht cohort study at follow up
| Population | No. cases (cases per 10 000) |
|---|---|
| Working population at follow up | 5499 (10 000/10 000) |
| Employees meeting CFS research criteria | |
| Prevalence at follow up | 199 (362/10 000) |
| Estimated incidence since baseline | 171 (311/10 000) |
| Estimated incidence per year | 47 (85/10 000) |
| Employees reporting CFS diagnosis | |
| Lifetime prevalence at follow up | 20 (36/10 000) |
| Number of employees meeting CFS criteria at follow up who reported lifetime CFS diagnosis | 2 (4/10 000) |
| Characteristic † | CFS-like employees, n = 199 | Non-CFS employees, n = 5300 | Adjusted odds ratio‡ (95% CI) |
|---|---|---|---|
| *Odds ratios not presented because groups were defined based on these variables. | |||
| †Data are mean (SD) unless stated otherwise. | |||
| ‡Adjusted for sex, age, and educational level. | |||
| CFS-like employees: employees who met research criteria for chronic fatigue syndrome. | |||
| Non-CFS employees: employees who did not meet research criteria for chronic fatigue syndrome. | |||
| Female sex, no. (%) | 55 (28%) | 1426 (27%) | 1.28 (0.92 to 1.79) |
| Age in years | 48.4 (7.6) | 45.8 (8.3) | 1.04 (1.02 to 1.05) |
| Educational level | |||
| High, no. (%) | 31 (16%) | 2054 (40%) | 0.21 (0.13 to 0.33) |
| Medium, no. (%) | 100 (51%) | 2290 (44%) | 0.6 (0.43 to 0.84) |
| Low, no. (%) | 64 (33%) | 833 (16%) | 1.00 |
| Fatigue severity (CIS) | 47.2 (4.6) | 23.1 (11.7) | * |
| Physical functioning (SF-36) | 44.2 (14.4) | 91.2 (13.2) | * |
| Exhaustion (MBI-GS) | 3.6 (1.2) | 1.6 (1.2) | 2.78 (2.48 to 3.12) |
| Anxiety (HAD) | 9.3 (4.4) | 4.8 (3.5) | 1.28 (1.24 to 1.33) |
| Depression (HAD) | 9.1 (4.2) | 3.7 (3.5) | 1.33 (1.28 to 1.37) |
| HAD case, no. (%) | 100 (50%) | 517 (10%) | 8.59 (6.37 to 11.6) |
| Absent from work, no. (%) | 49 (25%) | 341 (7%) | 3.74 (2.57 to 5.41) |
| Duration absenteeism, no. (%) | |||
| 0–4 months | 11 (22% of 49) | 109 (32% of 341) | 1.00 |
| 5–6 months | 4 (8% of 49) | 39 (11% of 341) | 1.07 (0.32 to 3.62) |
| 7–12 months | 11 (22% of 49) | 66 (19% of 341) | 1.68 (0.68 to 4.17) |
| 13 months or longer | 23 (48% of 49) | 127 (38% of 341) | 1.82 (0.81 to 4.07) |
