Table 3. Effect of vitamin K prophylaxis on classic VKDB/HDN.

Study, design and level of evidence	Participants	Comparison groups	Outcome measure	Effect measure (95% CI)
Sutherland et al.9 RCT	Full-term infants weighing 2260 g (5 lbs) or more; both breast and formula fed	Three groups: IM 100 mcg vitamin K3 (n=1132); IM 5 mg vitamin K3 (n=1063); placebo (normal saline; n=1143)	Minor bleeding (no local measures), moderate (innocuous sites requiring local measures) and severe (significant location such as central nervous system) bleeding	Any bleeding: RR 0.73 (0.56, 0.96) RD −0.02 (−0.038, −0.002) NNT 50 (26–479) moderate to severe bleeding: RR 0.19 (0.08, 0.46) RD −0.01 (−0.02, −0.006) NNT 74 (47–177)
Vietti et al.10 Quasi-RCT	Male infants for whom circumcision was performed on mothers' request	Two groups: IM 5 mg vitamin K3; no prophylaxis	Secondary bleeding after circumcision	RR 0.18 (0.08, 0.42) RD −0.11 (−0.16, −0.07) NNT 9 (6–15)

Abbreviations: HDN, hemorrhage disease of the newborn; IM, intramuscular; NNT, number needed to treat; RCT, randomized controlled trials; RD, risk difference; RR, relative risk; VKDB, vitamin K deficiency bleeding.

Note: Sutherland's study used two dosage regimes–100 mcg and 5 mg of vitamin K3; the data from these two groups are combined for the purpose of this review.