Comparison 1. Animal derived surfactant extract versus protein free synthetic surfactant.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Mortality	13	5413	Risk Ratio (M‐H, Fixed, 95% CI)	0.89 [0.79, 0.99]
1.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	0.93 [0.77, 1.13]
1.2 Treatment of established RDS	11	3800	Risk Ratio (M‐H, Fixed, 95% CI)	0.86 [0.75, 0.99]
2 Bronchopulmonary dysplasia	10	4321	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.93, 1.07]
2.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.85, 1.08]
2.2 Treatment of established RDS	8	2708	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [0.93, 1.11]
3 Chronic lung disease	8	4027	Risk Ratio (M‐H, Fixed, 95% CI)	0.99 [0.91, 1.09]
3.1 Prophylactic surfactant administration	2	1609	Risk Ratio (M‐H, Fixed, 95% CI)	1.01 [0.89, 1.15]
3.2 Treatment of established RDS	6	2418	Risk Ratio (M‐H, Fixed, 95% CI)	0.98 [0.86, 1.11]
4 Bronchopulmonary dysplasia or death	6	3811	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.91, 1.00]
4.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.90, 1.03]
4.2 Treatment of established RDS	4	2198	Risk Ratio (M‐H, Fixed, 95% CI)	0.94 [0.88, 1.01]
5 Chronic lung disease or death	5	3332	Risk Ratio (M‐H, Fixed, 95% CI)	0.97 [0.90, 1.04]
5.1 Prophylactic surfactant administration	2	1609	Risk Ratio (M‐H, Fixed, 95% CI)	0.99 [0.89, 1.10]
5.2 Treatment of established RDS	3	1723	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.86, 1.06]
6 Pneumothorax	11	5356	Risk Ratio (M‐H, Fixed, 95% CI)	0.65 [0.55, 0.77]
6.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	0.70 [0.46, 1.07]
6.2 Treatment of established RDS	9	3743	Risk Ratio (M‐H, Fixed, 95% CI)	0.64 [0.53, 0.77]
7 Patent ductus arteriosus	8	3322	Risk Ratio (M‐H, Fixed, 95% CI)	0.98 [0.91, 1.05]
7.1 Prophylactic surfactant administration	1	846	Risk Ratio (M‐H, Fixed, 95% CI)	0.97 [0.85, 1.09]
7.2 Treatment of established RDS	7	2476	Risk Ratio (M‐H, Fixed, 95% CI)	0.99 [0.90, 1.08]
8 Sepsis	10	5219	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.91, 1.10]
8.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	1.05 [0.92, 1.20]
8.2 Treatment of established RDS	8	3606	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.85, 1.09]
9 Necrotizing enterocolitis	8	3462	Risk Ratio (M‐H, Fixed, 95% CI)	1.38 [1.08, 1.76]
9.1 Prophylactic surfactant administration	1	846	Risk Ratio (M‐H, Fixed, 95% CI)	1.39 [0.83, 2.34]
9.2 Treatment of established RDS	7	2616	Risk Ratio (M‐H, Fixed, 95% CI)	1.37 [1.04, 1.81]
10 Intraventricular hemorrhage	10	5045	Risk Ratio (M‐H, Fixed, 95% CI)	1.07 [0.99, 1.15]
10.1 Prophylactic surfactant administration	2	1620	Risk Ratio (M‐H, Fixed, 95% CI)	1.13 [1.00, 1.27]
10.2 Treatment of established RDS	8	3425	Risk Ratio (M‐H, Fixed, 95% CI)	1.03 [0.94, 1.14]
11 Severe intraventricular hemorrhage, Grades 3 or 4	9	4241	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.91, 1.27]
11.1 Prophylactic surfactant administration	1	853	Risk Ratio (M‐H, Fixed, 95% CI)	1.43 [0.95, 2.15]
11.2 Treatment of established RDS	8	3388	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [0.85, 1.21]
12 Retinopathy of prematurity	6	3202	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.89, 1.01]
12.1 Prophylactic surfactant administration	2	1613	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.86, 1.05]
12.2 Treatment of established RDS	4	1589	Risk Ratio (M‐H, Fixed, 95% CI)	0.94 [0.86, 1.03]