Carnochan 2009.

Study characteristics
Patient sampling	Retrospective consecutive (?) patient series
Patient characteristics and setting	200 participants, 95 females (mean age = 63.7 years, SD = 9.2 years, range = 40 to 81 years) and 105 males (mean age = 66.4 years, SD = 7.9 years, range = 44 to 84 years), Scotland Histology of primary tumour Not reported; comorbidities: not reported Inclusion criteria Participants referred for consideration of surgery with a diagnosis or presumptive diagnosis of bronchogenic carcinoma to the authors' unit between June 2006 and January 2008 Exclusion criteria None listed Previous tests Spiral CT (all participants), and additional imaging (including ultrasound, MRI, and isotope scanning) was utilised where appropriate Clinical setting Thoracic surgery unit
Index tests	The participants were referred from different regions, which meant that both the primary CT and subsequent PET‐CT imaging was undertaken at different sites. All PET‐CT scans were reported by 2 radiologists, with node positivity based on SUV criteria selected by the scanning unit Covariates Type of PET‐CT scanner: not reported, but undertaken at different sites FDG dose: not reported Injection‐to‐scan time: not reported Attenuation correction: not reported Cut‐off values for test positivity (malignancy): node positivity based on SUV criteria selected by the scanning unit
Target condition and reference standard(s)	Mediastinoscopy with or without surgical resection (performed within 4 weeks of the PET‐CT scan)
Flow and timing	Data from 194/200 were available. The remaining 6 participants were classified as having benign disease by PET‐CT, but histology later showed that they all had NSCLC. However, the N‐stage for these participants was not reported
Comparative
Notes	There was no mention of funding source, but since this was a retrospective database study, it is likely that the study received no explicit funding Adverse events: not reported
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 a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
		Unclear	Low
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Yes
Was there a pre‐specified cut‐off value?	No
Was a positive result defined?	No
		Unclear	Unclear
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?	Unclear
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	No
		Low