Sun 2019.

Study characteristics
Patient Sampling	Cohort, consecutive, prospective
Patient characteristics and setting	Presenting signs and symptoms: patients with symptoms such as pain, swelling in the joints, tenderness, effusion, restriction of movements, and systematic symptoms such as fever, loss of weight/appetite, elevated erythrocyte sedimentation rate, and cough, breathlessness, and history of TB Age: osteoarticular TB: median 51 years (range 16 to 86) Sex, female: osteoarticular TB: 55% Children: no HIV infection: 0% Clinical setting: national level TB referral centre Past history of TB: not reported Participants on anti‐TB treatment: not reported Number of specimens evaluated: 166 Laboratory level: central Country: China World Bank Income Classification: middle income High TB burden: yes High TB/HIV burden: yes High MDR‐TB burden: yes
Index tests	Xpert MTB/RIF and Xpert Ultra WHO SOP or manufacturer's protocol followed: yes
Target condition and reference standard(s)	Bone or joint TB, fluid MGIT Composite reference standard: clinical, laboratory, histopathological, radiological and ≥ 6 months’ follow‐up Rifampicin resistance LJ‐DST Speciation: yes Decontamination: Yes
Flow and timing
Comparative
Notes
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
Could the selection of patients have introduced bias?		Low risk
Are there concerns that the included patients and setting do not match the review question?			Unclear
DOMAIN 2: Index Test (Xpert MTB/RIF)
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
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 2: Index Test (Xpert Ultra)
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
Could the conduct or interpretation of the index test have introduced bias?		Low risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			Low concern
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Unclear
Were the reference standard results interpreted without knowledge of the results of the index tests?	Yes
For rifampicin resistance testing, were the reference standard results interpreted without knowledge of the results of the index test?	Unclear
Could the reference standard, its conduct, or its interpretation have introduced bias?		Unclear risk
Are there concerns that the target condition as defined by the reference standard does not match the question?			Low concern
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?	Yes
Could the patient flow have introduced bias?		Low risk