Table 3.

Steps in calculation of pooled estimate

Study	Intervention group			Control group			Mean difference (Xi −Xj)	Variance of mean difference	Weights=1/Var(D)	WiDi	Pooled estimate	S.E. of pooled estimate
	n	Mean (Xi)	SD	n	Mean (Xj)	SD
	a	b	c	d	e	f	g (=b−e)	h	i (=1/h)	j (=i × g)	k	l
Kitlik et al. (13)*	25	40.96	14.80	25	65.64	17.79	−24.68	21.42	0.047	−1.152
Erdogan et al. (14)*	22	40.75	13.44	22	70.45	12.72	−29.70	15.57	0.064	−1.908	∑ WiDi/∑ Wi	$\sqrt{(1/\sum \text{wi})}$
Milan et al. (16)	17	45.90	33.9	17	71.80	39.90	−25.90	161.25	0.006	−0.161
									0.117	−3.221	−27.50	2.922

^*Data were reported as median in published article. Their mean and standard deviation were provided by authors