The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) for included studies
| Studies | Patient selection | Index test | Reference standard | Flow and timing | Scores | ||||||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | ||
| Echevarria et al26 | Y | Y | U | Low | Y | Y | Low | Y | U | Low | Y | Y | Y | Low | 12 |
| Shi et al27 | Y | Y | Y | Low | Y | U | Unclear | Y | U | Low | U | Y | Y | Low | 10 |
| Bastidas et al30 | U | Y | U | Unclear | Y | U | Unclear | Y | U | Low | Y | Y | Y | Low | 8 |
| Shafuddin et al31 | U | Y | Y | Unclear | Y | U | Unclear | Y | U | Low | Y | Y | N | High | 7 |
| Bisquera and Cruz32 | U | Y | U | Unclear | Y | U | Low | Y | U | Low | Y | Y | U | Unclear | 7 |
| Mantilla et al33 | U | Y | U | Unclear | Y | U | Low | Y | U | Low | Y | Y | Y | Low | 9 |
| Sangwan et al34 | Y | Y | Y | Unclear | Y | U | Low | Y | U | Low | Y | Y | U | Unclear | 9 |
| Xu et al35 | U | N | Y | High | N | U | High | Y | N | High | U | Y | Y | Unclear | 4 |
| Parras et al36 | U | Y | Y | Unclear | Y | U | Low | Y | U | Low | U | Y | Y | Low | 9 |
| Shi 2016 | U | Y | Y | Unclear | Y | U | Low | Y | Y | Low | U | Y | Y | Low | 10 |
| Yousif and El Wahsh37 | U | Y | Y | Unclear | Y | U | Unclear | Y | U | Low | U | Y | Y | Low | 8 |
| Echevarria et al28 | Y | Y | Y | Low | Y | U | Low | Y | Y | Low | Y | Y | Y | Low | 13 |
| Zidan et al10 | Y | Y | Y | Unclear | Y | U | Low | Y | U | Low | Y | Y | Y | Low | 12 |
| Collier et al38 | U | Y | U | Unclear | Y | U | Low | Y | U | Low | U | Y | U | Unclear | 6 |
| Rabbani and Brammer39 | U | Y | U | Unclear | U | U | Unclear | Y | U | Low | U | Y | Y | Low | 6 |
| Nafae 2014 | Y | Y | Y | Low | Y | U | Low | Y | U | Low | Y | Y | Y | Low | 12 |
| Steer et al6 8 | Y | Y | Y | Low | Y | U | Unclear | Y | U | Low | Y | Y | Y | Low | 11 |
QUADAS-2 criteria: (1) Was a consecutive or random sample of patients enrolled? (2) Was a case–control design avoided? (3) Did the study avoid inappropriate exclusions? (4) Could the selection of patients have introduced bias? (5) Were the index test results interpreted without knowledge of the results of the reference standard? (6) If a threshold was used, was it prespecified? (7) Could the conduct or interpretation of the index test have introduced bias? (8) Is the reference standard likely to correctly classify the target condition? (9) Were the reference standard results interpreted without knowledge of the results of the index tests? (10) Could the reference standard, its conduct, or its interpretation have introduced bias? (11) Was there an appropriate interval between index test and reference standard? (12) Did all patients receive the same reference standard? (13) Were all patients included in the analysis? (14) Could the patient flow have introduced bias?
N, No, represents negative answer for the corresponding question; U, Unclear, that is, the information provided in the individual studies was insufficient to answer the corresponding question; Y, Yes, represents certain answer for the corresponding question.