Table 1.

Formulae for meta-analysis

	Analytical strategy
	Sample size based	Inverse variance based
Inputs	Ni - sample size for study i	βi- effect size estimate for study i
	Pi−P-value for study i
	Δi - direction of effect for study i	sei - standard error for study i
Intermediate Statistics	Zi = Φ−1(Pi/2) * sign(Δi)	wi = 1/SEi2
Overall Z-Score		Z=β/SE
Overall P-value	P=2Φ(|−Z|)