Kurtz 2000.

Study characteristics
Patient sampling	Cross‐sectional study Prospective design Sample: unclear Direct comparison of different RADTs: no (but comparison of single‐swab versus double‐swab antigen extraction) Direct comparison of several throat culture techniques: yes (standard blood agar versus selective medium) Person performing the throat sample: not reported Exclusion if recent antibiotics use before inclusion: yes (previous 7 days) Clinical selection of patients: explicit criteria but not a score (see below) Presenting signs and symptoms: children with clinical signs of S. pyogenes pharyngitis ("fever, sore throat, and/or cervical adenitis and the absence of cough, rhinorrhea, lower respiratory infection, and otitis media") Age range for inclusion: 4 to 15 years
Patient characteristics and setting	Sample size: 256 Age (distribution): not reported GAS prevalence according to culture (with 95% confidence interval): 30.9% (95% CI not reported) Country of study: USA Sex (% of girls): not reported Clinical severity assessment: none Clinical setting: office‐based Single‐centre study
Index tests	Throat swab: 2 different swabs (each used first for culture and then for performing the RADT; we randomly chose to extract data for swab B) Commercial name of the RADT: Test Pack Plus (Abbott) Type of RADT: EIA
Target condition and reference standard(s)	Throat culture medium: standard and inhibitory (composite 2‐plate reference standard) Atmosphere of incubation: aerobic Duration of incubation: 48 hours GAS confirmation: bacitracin disk and latex test Number of plates inoculated: 2 Assessment of GAS antibody response: no Relevant details: 2 swabs were taken (A and B). Each swab was first inoculated onto a culture plate (standard or selective) and then used for performing the RADT. Culture positivity was defined as growth from either of the 2 plates. For the results of the RADT, we only extracted data for 1 swab, which was randomly chosen to be swab B.
Flow and timing	No follow‐up
Comparative
Type of study	Journal article
Notes	2 swabs were taken (A and B). Each swab was inoculated onto a culture plate (standard or selective) and then used for antigen detection. Culture positivity was defined as growth from either of the 2 plates. For the results of the RADT, we only extracted data for 1 swab, which was randomly chosen to be swab B. Funded in part by Abbott (manufacturer of the RADT).
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was it a cross‐sectional study or a RCT?	Yes
Were selection criteria clearly described (at least presenting signs and symptoms and age limits for inclusion)?	Yes
Was clinical selection of patients avoided?	No
Were patients seen in an ambulatory care setting?	Yes
		High	High
DOMAIN 2: Index Test All tests
Were the RADT results interpreted with blinding of the results of culture?	Yes
Was the type of the RADT mentioned (EIA or OIA)?	Yes
Were RADTs conducted during consultation time?	No
		Low	High
DOMAIN 3: Reference Standard
Were culture results interpreted with blinding of the results of the RADT?	Yes
Is the throat culture method likely to correctly identify GAS (laboratory culture on a blood agar plate during 48 hr)?	Yes
Were the culture medium, atmosphere, duration of incubation and GAS‐confirmation technique described?	Yes
		Low	Low
DOMAIN 4: Flow and Timing
Was the delay between the performance of the RADT and throat culture plating less than 48 hours?	Unclear
Did all patients receive a throat culture?	Yes
Did patients receive the same throat culture method?	Yes
Were undetermined/uninterpretable results reported?	Yes
Were withdrawals from the study explained?	Yes
		Low