I-A |
RCT specifically to assess the utility of the biomarker. The samples are collected and analysed in real-time |
Not necessary but could be useful |
I-B |
RCT not specifically to assess the utility of the biomarker. The samples are stored during the study and analysed after the study is finished, following a protocol |
One or more studies with consistent results |
II-B |
RCT not specifically to assess the utility of the biomarker. The samples are stored during the study and analysed after the study is finished, following a protocol |
Only one study, or several studies with inconsistent results |
II-C |
Non-randomized retrospective study aimed to assess the utility of the biomarker using samples from patients in an observational setting (standard treatment and follow-up) |
Two or more studies with consistent results |
III-C |
Non-randomized retrospective study aimed to assess the utility of the biomarker using samples from patients in an observational setting (standard treatment and follow-up) |
Only one study, or several studies with inconsistent results |
IV–V-D |
No aspect of the study is prospective |
Not necessary because these types of studies do not enable the clinical utility of the biomarker to be assessed |