| Study characteristics |
| Patient Sampling |
In order to assess the performance of the Xpert HIV‐1 quantitative assay on GeneXpert platform, 100 plasma samples were tested on both the platform and on the Abbott m2000 assay and the results were compared. Both the qualitative and the quantitative studies of the performance of the GeneXpert platform were cross‐sectional evaluations of samples obtained from facilities across the country. |
| Patient characteristics and setting |
HIV‐positive adults on antiretroviral therapy (ART); field in Kenya; contacted author who confirmed that samples were from those on ART. |
| Index tests |
Xpert HIV‐1 quantitative assay (Cepheid, Sunnyvale, CA, USA); done in peripheral lab on fresh plasma samples from the field. |
| Target condition and reference standard(s) |
High viral load > 1000 copies/mL; Abbott m2000. |
| Flow and timing |
In order to assess the performance of the Xpert HIV‐1 quantitative assay on GeneXpert platform, 100 plasma samples were tested on both the platform and on the Abbott m2000 assay and the results were compared. For viral load estimation on the GeneXpert platform, a total of 1.2 mL of plasma was added into the Xpert HIV‐1 Viral Load cartridge using a calibrated pipette. The cartridge was closed and loaded onto the machine. Test results were observed and recorded after 90 minutes. For comparison, viral load estimation was done on the Abbott m2000 using plasma according to manufacturer’s instructions. Test results were observed and recorded after 5 hours. |
| 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? |
Unclear |
|
|
| 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? |
|
|
Low concern |
| 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? |
|
|
Low concern |
| 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? |
Unclear |
|
|
| 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 |
|
