Table 2

Adverse event (AE) profile of each treatment group

Subject	AE description	AE actions	AE severity	AE serious*	AE related to treatment arm	AE outcome
A: non-operative treatment group
009	Fever-readmission	Further course of antibiotics given	Moderate	Yes*	Definitely	Resolved with sequelae
009	PICC line insertion	Weekly follow up appointments in clinic	Moderate	No	Unrelated	Resolved
025	Abdominal pain	–	Moderate	Yes*	Unrelated	Resolved
025	Sore throat	Ibuprofen given	Mild	No	Unrelated	Resolved
103	Abdominal pain	Antibiotics	Moderate	Yes*	Unlikely	Resolved
103	Recurrent appendicitis	Appendicectomy	Severe	Yes*	Unlikely	Resolved
162	Abdominal pain	Appendicectomy and hospital admission	Moderate	No	Definitely	Ongoing
162	Fluid collection	Continued antibiotics. Already in hospital	Moderate	No	Definitely	Ongoing
179	Abdominal pain	A&E attendance, bloods taken	Mild	No	Unrelated	Resolved
233	Abdominal pain	Appendicectomy and hospital admission	Moderate	No	Definitely	Resolved
233	Recurrence of appendicitis	Appendicectomy	Moderate	No	Definitely	Resolved
266	Recurrent appendicitis	Appendicectomy	Moderate	No	Definitely	Resolved
002	Abdominal pain	Admission to hospital	Mild	No	Probably	Resolved
157	Abdominal pain	–	Moderate	No	Possibly	Resolved
049	Abdominal pain	Advice given in A&E	Mild	No	Unrelated	Resolved
089	Patient visited GP surgery complaining of being sleepy for 2 weeks	None	Mild	No	Possibly	Ongoing
	Patient visited GP complaining of lethargy for 2 weeks	None	Mild	No	Possibly	Ongoing
	Abdomen pain	Patient had appendicectomy	Moderate	No	Probably	Resolved
184	Abdominal pain	Patient to be sent a clinic appointment	Mild	No	Unlikely	Ongoing
185	Rash over thighs	Patient given three doses of antihistamine	Mild	No	Unrelated	Resolved
276	Lethargic	Attended A+E. Discharged. Seen in clinic	Mild	No	Probably	Resolved
289	Generalised rash	Started antihistamines	Mild	No	Possibly	Resolved
B: Appendicectomy
014	Abdominal pain	Intravenous antibiotics	Moderate	Yes	Possibly	Resolved
014	Fever postop on readmission	NA	Mild	No	Possibly	Resolved
017	Vomiting	Ultrasound scan	Moderate	Yes	Unlikely	Resolved
123	Headache	Paracetamol given	Mild	No	Unrelated	Resolved
	Abdominal pain	Blood test	Moderate	No	Possibly	Resolved
	Intermittent vomiting	Blood test taken on 06/11/2017 was fine	Moderate	No	Possibly	Resolved
	Headache	Ibuprofen, time off school	Mild	No	Possibly	Resolved
	Sickness	Rest, off sick from school	–	No	Possibly	Resolved
	Sickness	Surgical review	Mild	No	Unrelated	Resolved
	Sickness	Off school	Mild	No	Unrelated	Resolved
264	Fluid collection	Drain insertion and hospitalisation	Moderate	No	Unrelated	Resolved
	PICC line insertion	Hospitalisation	Moderate	No	Unrelated	Resolved
	Drain insertion	Hospitalisation	Moderate	No	Unrelated	Resolved
040	Localised intra-abdominal fluid collection	Treatment with intravenous antibiotics	Moderate	No	Possibly	Resolved
167	Inflamed wound site	Patient started oral flucloxacillin	Moderate	No	Definitely	Resolved with sequelae
	Wound dehiscence	Attended accident and emergency	Moderate	No	Definitely	Resolved
	Diarrhoea	Telephone consultation with GP	Mild	No	Unlikely	Resolved with sequelae
	Vomiting	Call to GP—stomach bug diagnosed	Mild	No	Unrelated	Resolved
	Diarrhoea	Call to GP—stool sample	Mild	No	Unrelated	Resolved
	Pharyngitis	Started oral amoxicillin	Mild	No	Unrelated	Resolved
245	Wound infection	Started antibiotics	Moderate	No	Definitely	Resolved
247	Suture-related complication	Ultrasound and clinic appointment	Moderate	No	Probably	Resolved

PICC, peripherally inserted central venous catheter; GP, general practitioner.
*Note that AEs that were reported as serious (SAEs) during the early months of the trial are included here as reported on the basis of standardised reporting terminology in RCTs in that they resulted in either prolongation of hospital stay, readmission to hospital or death. However, since these were all predictable and related more to the disease process rather than the study interventions, we subsequently reclassified these ‘expected’ SAEs as AEs in protocol amendment 1 10 April 2017. Thus, although similar AEs did occur beyond the first 2 months of the study, they were no longer reported as SAEs.