Swathirajan 2017.

Study characteristics
Patient Sampling	This evaluation study was conducted in specimens collected between July 2015 and June 2016 from HIV‐1 patients attending the Y. R. Gaitonde Centre for AIDS Research and Education (YRG CARE), a tertiary care centre for HIV‐infected individuals in Chennai, Southern India. A total of 103 specimens that were tested by Abbott RealTime PCR as part of patient care services and had remaining samples stored in the freezer at −75 ± 5 °C, were utilized for this validation anonymously without using patient identifiers.
Patient characteristics and setting	HIV‐1 patients from a tertiary care centre for HIV‐infected individuals in Chennai, Southern India.
Index tests	Xpert HIV‐1 Viral Load assay on frozen plasma specimens done in a laboratory.
Target condition and reference standard(s)	High viral load > 1000 copies/mL; Abbott RealTime PCR.
Flow and timing	Both assays were performed as per the manufacturers’ instructions. A total of 103 specimens that were tested by Abbott RealTime PCR as part of patient care services and had remaining samples stored in the freezer at −75 ± 5 °C, were utilized for this validation anonymously without using patient identifiers. It was ensured that all the specimens were subjected to a single freeze–thaw cycle prior to testing using the Xpert HIV‐1 Viral Load assay.
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?	Unclear
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
Could the selection of patients have introduced bias?		Unclear risk
Are there concerns that the included patients and setting do not match the review question?			Unclear
DOMAIN 2: Index Test (All tests)
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
If a threshold was used, was it pre‐specified?	Yes
Could the conduct or interpretation of the index test have introduced bias?		Unclear risk
Are there concerns that the index test, its conduct, or interpretation differ from the review question?			High
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
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

Abbreviations: ART: antiretroviral therapy; DBS: dried blood spots; EDTA: ethylenediaminetetraacetic acid; PCR: polymerase chain reaction; POC VL: point‐of‐care viral load; RNA: ribonucleic acid; SAMBA: simple amplification‐based assay; Semi‐Q: semi‐quantitative.