Ahn 2009.

Study characteristics
Patient sampling	Retrospective study
Patient characteristics and setting	Sample size: 71. Age: unreported. Gender: unreported Patients diagnosed with gastric cancer (any site) and undergoing surgery Spectrum: T1 ‐ T3 and N0/N+ cases enrolled
Index tests	Index test: EUS; array: radial; frequency (MHz): 5 ‐ 12; criterion for T‐stage definition: EUS‐based 5‐layer structure of gastric wall; criterion for N‐stage definition: lymph node morphology and size (> 5 mm)
Target condition and reference standard(s)	Target conditions: gastric carcinoma 1) T1 (67/71) vs T2, 2) N0 (65/71) vs N+ Reference standard: pathology evaluation of surgical specimen Reference and index test completely independent
Flow and timing	No uninterpretable findings reported
Comparative
Notes	Country: Korea Relevant clinical information: same clinical data available for test results interpretation as those available when test used in practice
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
		Low	Low
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
If a threshold was used, was it pre‐specified?	Yes
		Low	Low
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Yes
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Unclear
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Yes
		Unclear