Table 1.
Level | Rating | Criteria |
---|---|---|
Strong | +++ or −−− | Consistent findings in multiple studies of good |
methodological quality OR in one study of excellent | ||
methodological quality | ||
Moderate | ++ or −− | Consistent findings in multiple studies of fair |
methodological quality OR in one study of good | ||
methodological quality | ||
Limited | + or − | One study of fair methodological quality |
Conflicting | ± | Conflicting findings |
Unknown | ? | Only studies of poor methodological quality |
[..] reference number, + positive result, − negative result