Table 2.
GRADE evidence summary.
| Vitamin K versus no vitamin K or placebo for improving outcomes | ||||||
| Population: women during pregnancy | ||||||
| Settings: Liverpool, USA, and the Netherlands | ||||||
| Intervention: vitamin K versus no vitamin K or placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with no vitamin K or placebo | Risk with Vitamin K | |||||
| Perinatal death | See comment | See comment | Not estimable | — | See comment | The outcome was not reported in any trials. |
| Neonatal bleeding | 2 per 1,000 |
2 per 1,000
(1 to 5) |
RR 1.16
(0.59 to 2.29) |
17503 (4 RCTs) |
⊕○○○ VERY LOWa,b |
|
| Maternal bleeding | See comment | See comment | Not estimable | — | See comment | The outcome was not reported in any trials. |
| Neonatal death | See comment | See comment | Not estimable | — | See comment | The outcome was not reported in any trials. |
| Preterm birth | See comment | See comment | Not estimable | — | See comment | The outcome was not reported in any trials. |
| Neonatal jaundice | 49 per 1,000 |
72 per 1,000
(36 to 142) |
RR 1.47
(0.74 to 2.91) |
533 (1 RCT) |
⊕○○○ VERY LOWb,c |
|
| Maternal plasma vitamin K1 | The mean maternal plasma vitamin K1 was 0 | The mean maternal plasma vitamin K1 in the intervention group was 2.46 higher (0.98 higher to 3.93 higher) | — | 65 (2 RCTs) |
⊕○○○ VERY LOWd,e |
|
| *The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). | ||||||
| CI: Confidence interval; RR: Risk ratio | ||||||
| GRADE Working Group grades of evidence | ||||||
| High quality: We are very confident that the true effect lies close to that of the estimate of the effect | ||||||
| Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different | ||||||
| Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect | ||||||
| Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
Explanations.
aBoth included trials are quasi design and hence suffer from high bias risk for selection of the participants (−2).
bWide 95%CI.
cOne quasi RCT with high bias risk for selection of the participants (−2).
dMost of domains are unclear risk of bias (−1).
eWide 95%CI and small sample size (−2).