Characteristics of UK children, adolescents and adults, and Dutch adolescents
| Characteristics | UK (aged <12 years) | UK (aged 12–18 years) | NL (aged 12–18 years) | UK adults (aged 19–65 years) | ||||
|---|---|---|---|---|---|---|---|---|
| N | N | N | N | |||||
| Age (years), mean (SD) | 210 | 9.3 (2.0) | 1568 | 15.0 (1.8) | 135 | 15.8 (1.3) | 10675 | 40.1 (11.7) |
| Sex (female), frequency (%) | 210 | 119 (56.7) | 1568 | 1162 (74.1) | 135 | 111 (82.2) | 10675 | 8 (77.9) |
| BMI (kg/m2), mean (SD) | 49 | 18.5 (3.8) | 579 | 22.1 (6.5) | 134 | 21.0 (2.9) | 5598 | 26.2 (5.7) |
| Duration of illness (months), median (IQR) | 161 | 12, 7–23 | 1293 | 18, 11–28 | 135 | 16, 9–28 | 8488 | 36, 16–96 |
| Disability*, median (IQR) | 178 | 45, 25–65 | 1411 | 50, 33–70 | 135 | 52, 48–55 | 9282 | 40, 20–60 |
| Fatigue† (Chalder), median (IQR) | 190 | 23, 20–28 | 1425 | 25, 22–29 | – | – | 9405 | 28, 24–31 |
*UK cohorts used SF-36 physical function subscale to measure disability. The Dutch cohort used the CHQ-CF87 physical function subscale.
†All Dutch children had severe fatigue (CIS20-R subjective fatigue scale score ≥40).
BMI, body mass index; CHQ-CF87, Child Health Questionnaire; SF-36, short form 36.