Paradise 1984.

Methods	Allocation: randomised; stratification for age (3 age groups) with use of balanced blocks of 4 Design: parallel groups. Study was done alongside a non‐randomised cohort study
Participants	Number: 91 children randomised out of 2043 patients screened Age: 3 to 15 years Setting: Children's Hospital of Pittsburgh (USA). Participants were recruited among hospital outpatients, children referred by community practitioners or directly by parents between August 1971 and June 1982 Eligibility criteria: History of recurrent episodes of throat infection (i.e. tonsillitis, pharyngitis or tonsillopharyngitis) The episodes had to meet defined standards in each of 4 categories: (1) Frequency of occurrence: 7 or more episodes in the preceding year, 5 or more in each of the 2 preceding years, or 3 or more in each of the preceding 3 years (2) Clinical features: each episode characterised by 1 or more of the following: oral temperature of at least 38.3 °C, cervical lymphadenopathy (enlarged (> 2 cm) or tender cervical lymph nodes), tonsillar or pharyngeal exudate, or positive culture for group A beta‐haemolytic Streptococcus (3) Treatment: antibiotics administered at conventional dosage for proven or suspected streptococcal episodes (4) Documentation: each episode and its qualifying features substantiated by concurrent notation in a medical record Exclusion criteria: Judged to require prompt removal of large tonsils or adenoids because of proven or suspected alveolar hypoventilation, sustained difficulty in swallowing or marked discomfort in breathing Prior tonsil or adenoid surgery, major physical or emotional disease, structural middle‐ear damage or sensorineural hearing loss, hypogammaglobulinaemia (IgG, IgA or IgM level > 2 SD below the mean value for the child's age) Simultaneous enrolment of a sibling in the study, or inability to meet the projected schedule of follow‐up visits
Interventions	Intervention group 1: tonsillectomy (dissection and snare technique); n = 27 Intervention group 2: adenotonsillectomy (dissection and snare technique for tonsillectomy; reverse adenotomes and curettes for adenotomy); n = 16 Comparator group 1: non‐surgical treatment; n = 29 Comparator group 2: non‐surgical treatment; n = 19 The trial data were pooled (and not presented separately) in the publication: Intervention group: tonsillectomy or adenotonsillectomy; n = 43 Comparator group: non‐surgical treatment; n = 48 Use of additional interventions: cultures for the presence of group A streptococci in case of suspected or diagnosed throat infections showing growth of any degree were considered positive. Penicillin V (250 mg) ‐ or erythromycin (10 mg/kg body weight) in case of presumed allergy to penicillin ‐ was prescribed 4 times daily for 10 days for all participants with positive cultures and also for those whose cultures were negative but who had been treated presumptively from the outset and had improved markedly within 48 hours
Outcomes	Primary outcome: Observed episodes of throat infections based on 3 criteria: moderate/severe sore throat; group A streptococcal infection; or "counting" method. Secondary outcomes: Proportion of visits with isolated cervical lymphadenopathy Number of parent‐reported sore throat days Number of days of sore throat‐associated school absence A standardised telephone or in‐person inquiry was made bi‐weekly concerning the day‐by‐day occurrence of specified symptoms and events, including sore throat and absence from school. Standardised clinical examinations were performed at 6‐week intervals and at the time of respiratory illnesses
Funding sources	ER McCluskey Memorial Research. Programme fund from the Children's Hospital in Pittsburgh and National Institute of Child Health and Human Development
Declarations of interest	None declared
Notes	Not balanced for history of episodes of throat infection before trial entry and parental socioeconomic status (2 of 11 comparisons): 65% in the control group were skilled workers or executives/professionals, whereas 65% in the surgery group were of semi‐skilled/unskilled workers or disabled/unemployed/receiving public assistance/other. 47% in the surgery group had more than 7 infections within the past year, whereas only 23% in the control group met this criterion. 67% in the control group met the criterion of >= 3 infections per year over the past 3 years
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "assigned randomly, within categories and balanced blocks of four"
Allocation concealment (selection bias)	Unclear risk	Comment: not described. Small block size (4 participants) potentially allows prior knowledge of allocation
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No blinding. However, there was a clear protocol for management of reported sore throats
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding. Patients were followed up bi‐weekly by either a standardised telephone or in‐person inquiry. Patients reported their symptoms
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: significant number of patients not included in analyses especially in years 2 and 3. Patients were excluded from analysis for these reasons 1) loss to follow‐up; 2) not treated as randomised (patients in the control arm who received surgery were excluded from analysis); 3) did not complete the full follow‐up periods in the analysis Proportion of patients not included in analysis is higher in the control groups Children electing for surgery in the control group Participants not included in analyses total: Year 1 ‐ 18/91 (20%) Intervention arm: 5/43 (12%) Control arm: 13/48 (27%) Year 2 ‐ 31/91 (34%) Intervention arm: 12/43 (28%) Control arm: 19/48 (40%) Year 3 ‐ 49/91 (54%) Intervention arm: 21/43 (49%) Control arm: 28/48 (58%)
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit a judgement of low or high risk
Other bias	Unclear risk	Proportion of patients who did not receive assigned treatment: Participants in intervention group who did not have surgery within 90 days: 8/43 (19%) Participants in control group who had surgical treatment (cumulative numbers) Year 1 = 7/48 (15%) Year 2 = 12/48 (25%) Year 3 = 16/48 (33%) Baseline characteristics: not balanced for history of episodes of throat infection before trial entry and parental socioeconomic status (2 of 11 comparisons)