Participant characteristics, N = 401
| Age, years, median (IQR) | 1.6 (0.79–3.38) | |
| Sex, male, n (%) | 203 (50.62) | |
| Ethnicity, n (%) | ||
| White British | 280 (69.83) | |
| White other | 38 (9.48) | |
| Mixed | 27 (6.73) | |
| Pakistani | 21 (5.24) | |
| Other Asian | 11 (2.74) | |
| African | 8 (2.00) | |
| Indian | 5 (1.25) | |
| Chinese | 5 (1.25) | |
| Bangladeshi | 4 (1.00) | |
| Caribbean | 1 (0.25 | |
| Black British | 1 (0.25) | |
| Mother’s age, years, median (IQR) | 32 (29–36) | |
| Number of siblings, median (IQR) | 1 (0–1) | |
| Parent believed child to be febrile at point of assessment, n (%)a | 119 (29.75) | |
| Fever medication in past 6 hours, n (%)a | 134 (33.50) | |
| Parent report of fever duration, days, median (IQR) | 1.5 (0.5–3) | |
| Illness duration, days, median (IQR) | 3 (2–7) | |
| Recruitment site, n (%) | ||
| OOH primary care | 34 (8.48) | |
| In-hours primary care | 367 (91.52) | |
↵a N = 400 as there was missing data point for one participant for these questions. IQR = interquartile range.
OOH = out-of-hours.