Proportions followed up for key outcome measures
illness
In the observational study, the duration of illness and illness severity in days 2–4 following the consultation were recorded for 232/312 (74.4%) participants. Re-consultation was available for 271/312 (86.9%), progression of illness for 290/312 (92.9%), and side effects for 228/312 (73.1%). In the combined data, 549/744 (73.8%) reported the duration and severity of illness. Re-consultation was recorded for 672/744 (90.3%), progression of illness for 705/744 (94.8%) (Supplementary Table S1), and side effects for 538/744 (72.3%).