Table 2.
Demographics of the endophenotype subgroups according to severity.
| Fatigue (F) |
Musculoskeletal pain (MP) |
Mood disturbance (MD) |
Acute sickness (AS) |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MildΔ (n = 81) | SevereΔ (n = 81) | p value | MildΔ (n = 88) | SevereΔ (n = 88) | p value | MildΔ (n = 90) | SevereΔ (n = 90) | p value | MildΔ (n = 88) | SevereΔ (n = 88) | p value | |
| Age* (range) | 37 (19–47) | 34 (18–43) | 0.23 | 22 (18–39) | 37 (27–45) | 0.001 | 34 (20–49) | 30 (17–41) | 0.01 | 36 (24–47) | 30 (18–45) | 0.03 |
| Female€; n (%) | 32 (40) | 47 (58) | 0.18 | 49 (50) | 48 (49) | 0.88 | 46 (51) | 53 (59) | 0.29 | 49 (56) | 46 (52) | 0.65 |
| Infection type€; n (%) | 0.025 | 0.001 | 0.158 | 0.001 | ||||||||
| EBV | 26 (32) | 27 (33) | 46 (52) | 10 (11) | 31 (34) | 26 (29) | – | 18 (20) | 32 (36) | – | ||
| RRV | 26 (32) | 13 (16) | 8 (9) | 33 (38) | 22 (25) | 16 (18) | – | 42 (48) | 5 (6) | – | ||
| QF | 12 (15) | 9 (11) | 13 (15) | 17 (19) | 16 (18) | 13 (14) | – | 9 (10) | 23 (26) | – | ||
| Undeterminate | 17 (21) | 32 (40) | 21 (24) | 28 (32) | 21 (23) | 35 (39) | – | 19 (22) | 28 (32) | – | ||
| Prior severe episode&; n (%) | 3 (4) | 9 (11) | 0.07 | 1 (1) | 12 (14) | 0.001 | 1 (1) | 12 (13) | 0.001 | 6 (7) | 10 (11) | 0.29 |
*Median values and IQR are reported and compared by Mann-Whitney tests. €Frequencies are compared by Chi (Khera et al., 2018) test. &Defined in Fatigue and Musculoskeletal pain endophenotype subgroups as previous episodes of severe and prolonged fatigue or pain (>30 days); or previous severe acute infection for the Acute sickness endophenotype. For the Mood disturbance endophenotype, a history of premorbid mood disorder was available only for n = 71 individuals (n = 30 and n = 41 from the severe and mild illness groups respectively). Δ Described as mild or severe illness severity groups in Fig. 1b.