Comparison 1. HFNC versus CPAP for primary respiratory support after birth.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Death or CLD	4	439	Risk Ratio (M‐H, Fixed, 95% CI)	1.66 [0.56, 4.94]
1.1 < 28 weeks	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
1.2 28 ‐ 32 weeks	1	37	Risk Ratio (M‐H, Fixed, 95% CI)	2.55 [0.29, 22.31]
1.3 ≥ 32 weeks	1	88	Risk Ratio (M‐H, Fixed, 95% CI)	6.54 [0.32, 132.33]
1.4 < 37 weeks' (subgroup data not available)	3	314	Risk Ratio (M‐H, Fixed, 95% CI)	0.76 [0.15, 3.77]
2 CLD	4	439	Risk Ratio (M‐H, Fixed, 95% CI)	2.07 [0.64, 6.64]
2.1 < 28 weeks	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
2.2 28 ‐ 32 weeks	1	37	Risk Ratio (M‐H, Fixed, 95% CI)	2.55 [0.29, 22.31]
2.3 > 32 weeks	1	88	Risk Ratio (M‐H, Fixed, 95% CI)	6.54 [0.32, 132.33]
2.4 < 37 weeks' (subgroup data not available)	3	314	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.19, 5.97]
3 Death	4	439	Risk Ratio (M‐H, Fixed, 95% CI)	0.36 [0.01, 8.73]
3.1 < 28 weeks	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.2 28 ‐ 32 weeks	1	37	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.3 > 32 weeks	1	88	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
3.4 < 37 weeks' (subgroup data not available)	3	314	Risk Ratio (M‐H, Fixed, 95% CI)	0.36 [0.01, 8.73]
4 Treatment failure within 7 days of trial entry	4	439	Risk Ratio (M‐H, Fixed, 95% CI)	1.30 [0.73, 2.34]
4.1 < 28 weeks	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
4.2 28 ‐ 32 weeks	1	37	Risk Ratio (M‐H, Fixed, 95% CI)	0.17 [0.01, 3.34]
4.3 > 32 weeks	1	88	Risk Ratio (M‐H, Fixed, 95% CI)	1.13 [0.41, 3.08]
4.4 < 37 weeks' (subgroup data not available)	3	314	Risk Ratio (M‐H, Fixed, 95% CI)	1.77 [0.81, 3.89]
5 Intubation within 7 days of trial entry	2	247	Risk Ratio (M‐H, Fixed, 95% CI)	2.38 [0.86, 6.57]
6 Intubation at any time point after trial entry	1	125	Risk Ratio (M‐H, Fixed, 95% CI)	1.16 [0.49, 2.71]
7 Duration of any respiratory support (days)	2	192	Mean Difference (IV, Fixed, 95% CI)	0.97 [0.08, 1.86]
8 Duration of supplemental oxygen (days)	1	125	Mean Difference (IV, Fixed, 95% CI)	3.70 [‐0.66, 8.06]
9 Duration of hospitalisation (days)	3	262	Mean Difference (IV, Fixed, 95% CI)	0.50 [‐0.55, 1.56]
10 Pneumothorax	3	369	Risk Ratio (M‐H, Fixed, 95% CI)	0.54 [0.17, 1.79]
11 Nosocomial sepsis	4	439	Risk Ratio (M‐H, Fixed, 95% CI)	1.29 [0.66, 2.54]
12 Gastrointestinal perforation or severe NEC	1	125	Risk Ratio (M‐H, Fixed, 95% CI)	3.46 [0.14, 83.27]
13 Days to full feeds	2	195	Mean Difference (IV, Fixed, 95% CI)	‐0.41 [‐1.46, 0.63]
14 Nasal trauma	3	258	Risk Ratio (M‐H, Fixed, 95% CI)	0.62 [0.34, 1.15]