Koskenkorva 2013.

Methods	Allocation: randomised ‐ simple randomisation Design: parallel groups, average follow‐up about 6 months
Participants	Number: 86 adults out of 260 screened Age: 13 years and above Setting: tertiary care ENT centre in Oulu (Finland) Eligibility criteria: 3 or more episodes of pharyngitis within the previous 12 months These episodes had to be disabling, prevent normal functioning, be severe enough for the patient to seek medical attention and be thought to involve the palatine tonsils It was not necessary for culture or antigen tests to have shown infection with group A Streptococcus Exclusion criteria: History of peritonsillar abscess, chronic tonsillitis, ongoing antibiotic treatment, residence outside of the Oulu region, pregnancy or previous illness making same‐day surgery unfeasible
Interventions	Intervention group: tonsillectomy (total extracapsular tonsillectomy using blunt or diathermy dissection); n = 46 (45 patients underwent tonsillectomy and 1 patient underwent adenotonsillectomy) Comparator group: watchful waiting (placement on waiting list for tonsillectomy to undergo surgery after 5 to 6 months); n = 40 Use of additional interventions: no information was provided on a standardised treatment strategy in cases where there was an acute sore throat/pharyngitis recurrence during follow‐up
Outcomes	Primary outcome: Proportion of patients who had a severe episode of pharyngitis within 5 months. A severe episode was defined as acute throat pain and signs suggesting the symptoms originated in the pharynx (oedema, erythema, exudative tonsillitis, anterior cervical lymphadenitis), which led to medical consultation. In addition, the serum level of C‐reactive protein had to be higher than 40 mg/L either at the day of the medical consultation or 3 days later. If a blood sample was not taken, the result of a throat culture had to show other than normal flora, and the patient had to grade the throat pain as severe Secondary outcomes: Proportion of patients with any episode of pharyngitis (sore throat lasting at least 2 days) and episodes with medical consultation during the 5‐month follow‐up Times to pharyngitis episodes Reported number of sore throat episodes Reported number of sore throat days Reported number of days absent from school or work Reported number of symptomatic days during follow‐up Health‐related quality of life (Glasgow Benefit Inventory) in the intervention group (Robinson 1996) Adverse effects related to tonsillectomy The patients used a symptom diary to record the presence and severity (mild, moderate or severe) of throat pain, cough, rhinitis, fever and absence from school or work. Data concerning acute visits and tonsillectomy were recorded from patients' charts Patients were advised to visit the study physician or their general practitioner whenever they had acute symptoms suggestive of pharyngitis. In addition, they were told that it was important to seek medical advice for their symptoms during the trial exactly as they had done before. At the acute visit, patients underwent a clinical examination including a throat swab and a blood test to measure serum levels of C‐reactive protein. The blood test was repeated 3 days later. All laboratory and microbiological analyses were performed by staff blinded to the clinical data
Funding sources	None declared
Declarations of interest	None declared
Notes	Baseline characteristics were balanced
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "We assigned patients ... using simple randomisation"
Allocation concealment (selection bias)	Low risk	Quote: "The allocation sequence was concealed from the investigators using sequentially numbered sealed opaque envelopes"
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding. No additional information about management of sore throats
Blinding of outcome assessment (detection bias) All outcomes	High risk	No blinding. Outcomes were patient‐reported (subjective)
Incomplete outcome data (attrition bias) All outcomes	Low risk	No losses to follow‐up 2 patients, 1 in each group, lost their symptom diaries but reported not having consulted a physician for throat pain. These patients were assumed to have no symptoms during the study period
Selective reporting (reporting bias)	Unclear risk	Insufficient information to permit a judgement of low or high risk
Other bias	Low risk	No other sources of bias were found Proportion of patients who did not receive assigned treatment: Participants in intervention group who did not have surgery: 0/46 (0%) Participants in control group who had surgical treatment within 5 months: 3/40 (8%)