Table 1 GRADE approach.
(a) Quality of evidence definitions | |
High | We are very confident that the true measurement property lies close to that of the estimate of the measurement property |
Moderate | We are moderately confident in the measurement property estimate: the true measurement property is likely to be close to the estimate of the measurement property, but there is a possibility that it is substantially different |
Low | Our confidence in the measurement property estimate is limited: the true measurement property may be substantially different from the estimate of the measurement property |
Very low | We have very little confidence in the measurement property estimate: the true measurement property is likely to be substantially different from the estimate of the measurement property |
(b) Instructions on downgrading | |
Risk of bias | |
No | There are multiple analyses of at least adequate quality, or there is one study of very good quality available |
−1 Serious | There are multiple analyses of doubtful quality available, or there is only one study of adequate quality |
−2 Very serious | There are multiple analyses of inadequate quality, or there is only one study of doubtful quality available |
−3 Extremely serious | There is only one study of inadequate quality available |
Inconsistency | |
No | Results could be meta-analytically pooled or ≥75% of the analyses had consistent results |
−1 Serious | <75% of analyses had consistent results |
−2 Very serious | <70 and ≥65% had consistent results If <65% had consistent results GRADE will not be performed because there is not enough evidence |
Imprecisionª | As recommended by COSMIN due to the high total sample sizes no downgrading for imprecision was done |
Indirectness | As recommended by COSMIN due to our inclusion criteria of ≥80% population with a psychotic disorder no downgrading for indirectness was done |
