Theron 2011

Study characteristics
Patient sampling	Cross‐sectional design, consecutive enrolment, retrospective data collection
Patient characteristics and setting	Presenting signs and symptoms: presumptive TB based on compatible signs and symptoms Age: median 36 years, range 18 to 83 years Sex, female: 32.3% HIV infection: 31.3% History of TB: 34.3% Sample size: 480 Clinical setting: 2 primary care clinics in a high HIV prevalence area Laboratory level: central Country: South Africa, Cape Town World Bank Income Classification: middle income High TB burden country: yes High MDR‐TB burden country: yes High TB/HIV burden country: yes TB incidence rate: 993 per 100,000 MDR‐TB prevalence: percentage MDR‐TB among new TB cases = 0.9% (Source: survey in Western Cape Province, 2002) and among retreatment cases = 4.0% (Source: survey in Western Cape Province, 2002) Prevalence of TB cases in the study: 29.4%
Index tests	Index: Xpert MTB/RIF
Target condition and reference standard(s)	Target condition: pulmonary TB Reference standard for pulmonary TB: MGIT 960 Target condition: rifampicin resistance Reference standard for rifampicin resistance: MGIT 960
Flow and timing
Comparative
Notes	Short‐term follow‐up cultures were obtained; 16 of 19 Xpert MTB/RIF‐positive culture‐negative participants were considered likely to be TB cases based on follow‐up cultures, gene sequencing, and the presence of characteristic radiographic features using a standardized scoring system
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 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
		Low	Low
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results for TB detection interpreted without knowledge of the results of the index test?	Yes
Were the reference standard results for rifampicin resistance detection interpreted without knowledge of the results of the index test?	Yes
		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?	Yes
		Low