Table 3. GRADE Summary of the Quality of the Body of Evidence for Each Outcome.
| Outcomes | Source of data (M FUP) | Illustrative comparative risksa (95% CI) | No of participants (Studies) | GRADEb quality of the evidence | |
|---|---|---|---|---|---|
|
| |||||
| Comparison (Assumed risk) | BAIs (Corresponding risk) | ||||
| Quantity of alcohol consumed | Self-report (7 days) | Mean 7 standard drinks | Mean 0.05 SD lower (0.13 lower to 0.03 higher) | 2703 (9 studies) | very low1,2 |
| BAC | Self-report (7 days) | Mean 0.15 BAC | Mean 0.20 SD lower (0.33 lower to 0.07 higher) | 899 (5 studies) | very low1,3 |
Notes. M FUP = Mean Follow-up timing; CI = Confidence Interval; SD = Standard Deviation; BAI = Brief Alcohol Intervention
The basis for the assumed risk (e.g. the median comparison group risk across studies) is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
GRADE Working Group grades of evidence: High quality = Further research is very unlikely to change our confidence in the estimate of effect; Moderate quality = Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; Low quality = Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; Very low quality = We are very uncertain about the estimate.
A substantial majority of data is at high risk of detection and attrition bias.
All confidence intervals include important effects and no effects at all, including important negative and positive effects.
This is a main outcome for this intervention and this review, but only 56% of studies are included in this analysis.