Table 7.

Analysis of pulmonary function index (day) of three screened reports through fixed-effect model.

Study or subgroup	Mean	Experimental		Mean	Control		Weight	Mean difference
		SD	Total		SD	Total		IV, fixed, 95% CI
Li Qiaoxiang 2017	3.42	0.87	60	2.91	0.44	60	15.6%	0.51 [0.26, 0.76]
Ma Ying 2018	3.32	0.31	66	2.67	0.33	66	79.6%	0.65 [0.54, 0.76]
Zhao Qi 2018	6.36	1.03	42	5.95	1.04	42	4.8%	0.41 [-0.03, 0.85]
Total (95% CI)			168			168	100%	0.62 [0.52, 0.71]

Heterogeneity: chi² = 1.91; df = 2 (P = 0.38); I² = 0%. Test for overall effect: Z = 12.40 (P < 0.00001).