QUADAS-2 Domain | Limitations observed in CAD4TB evidence base | Published and unpublished studies affected by limitation (number of studies with major concern/total) |
Patient selection | Exclusion of participants Potential biased assessment of diagnostic accuracy Limited generalisability to how software will be used in the field | Systematic screening (2/3) Triage (1/6) |
Index test (CAD4TB) | CXR for training, and evaluation of accuracy originate from same dataset Potential biased assessment of diagnostic accuracy Limited generalisability to how software will be used in the field | Systematic screening (1/3) Triage (2/6) |
Threshold score not pre-specified Potential biased assessment of diagnostic accuracy Limited generalisability to how software will be used in the field | Systematic screening (2/3) Triage (4/6) | |
Reference standard for TB | Composite reference standard Potential biased assessment of diagnostic accuracy | Systematic screening (0/3)# Triage (1/6) |
Use of NAAT as reference standard Potential biased assessment of diagnostic accuracy due to limited sensitivity for smear-negative TB | Systematic screening (0/3)# Triage (3/6) |
TB: tuberculosis; CXR: chest radiography; NAAT: nucleic acid amplification test. #: microbiological tests were used to diagnose TB in all persons with symptoms or human-reader identified radiographic abnormalities; asymptomatic persons with radiographs interpreted as “normal” were assumed to not have TB, and did not undergo microbiological testing.