| Under 12 years Mean (SD) | 12 years and over Mean (SD) | Mean difference (95% CI) | |
| Chalder fatigue | 8.3 (3.0) | 8.7 (2.7) | −0.4 (−1.5, 0.8) |
| SCAS* | 34.4 (17.6) | 27.0 (19.4) | 7.4 (−1.5, 16.4) |
| Pain VAS | 39.7 (27.8) | 46.1 (31.1) | −6.5 (−20, 7.1) |
| SF36 | 19.3 (4.9) | 19.7 (5.3) | −0.3 (−2.6, 1.9) |
| Total number of symptoms | 8.1 (2.2) | 8.3 (2.6) | −0.2 (−1.2, 0.9) |
| Time at school (as percentage of possible total) | 43.3 (21.4) | 34.7 (22.8) | 8.6 (−1.9, 19) |
| Time to assessment (months) | 20.4 (16.7) | 24.7 (19.6) | −4.3 (−12.3, 3.6) |
*Only children up to 14 years were only asked to complete the Spence anxiety scale. At 14 years and older, children were asked to complete the hospital anxiety depression scale (HADS).
SCAS, Spence children's anxiety scale; VAS, visual analog scale.