Table 6.
Levels of evidence for the quality of the questionnaires
| Internal consistency | Reliability | Content validity | Structural validity | Hypothesis testing | Cross-cultural validity | Criterion validity | |
|---|---|---|---|---|---|---|---|
| CES-D | +++ | NA | NA | +++ | +++ | + | ++ |
| CUDOS | ++ | ++ | NA | − − | + | + | + |
| DCS | +++ | NA | NA | +++ | +/− | ++ | NA |
| DDSRS | ? | NA | NA | NA | ? | NA | ? |
| EDS | NA | NA | NA | ++ | NA | NA | NA |
| HADS | +++ | NA | NA | +++ | ++ | NA | NA |
| McSad | NA | NA | NA | NA | +++ | NA | NA |
| PHQ−9 | +++ | ? | ? | +/− | ++ | ? | +++ |
| WHO-5 | +++ | ? | ? | ++ | ++ | + | ? |
+++ strong positive evidence; ++ moderate positive evidence; + limited positive evidence; − − −strong negative evidence; − − moderate negative evidence; +/− inconclusive; ? unknown, due to poor methodological quality; NA no information available