Table 3 Distribution of ME/CFS precipitants according to post-exertional malaise severity quartiles
| Â | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 |
|---|---|---|---|---|
Patients, n (%) | 23 (11.7) | 74 (37.6) | 73 (37.1) | 27 (13.7) |
ME/CFS precipitants | ||||
 Identified, n (%) | 18 (78.3) | 46 (62.2) | 56 (76.6) | 19 (70.4) |
 Non-infectious, n (%) | 4 (17.4) | 17 (23) | 17 (23) | 4 (14.8) |
 Infectious, n (%) | 14 (60.9) | 29 (39.2) | 39 (53.4) | 15 (55.6) |
  Influenza-like illness | 10 (43.5) | 13 (17.6) | 21 (28.8) | 7 (25.9) |
  Respiratory | 0 (0.0) | 9 (12.2) | 6 (8.2) | 3 (11.1) |
  Gastrointestinal | 0 (0.0) | 3 (4.1) | 3 (4.1) | 5 (18.5) |
  Urinary | 0 (0.0) | 1 (1.4) | 1 (1.4) | 0 (0.0) |