Comparison 6. Long‐term follow‐up.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Bayley Mental Developmental Index (MDI) < ‐2 SD	7	333	Risk Ratio (M‐H, Fixed, 95% CI)	0.81 [0.47, 1.38]
2 Bayley MDI < ‐2 SD in survivors tested	7	232	Risk Ratio (M‐H, Fixed, 95% CI)	0.74 [0.45, 1.22]
3 Bayley Psychomotor Developmental Index (PDI) < ‐2 SD	1	118	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.34, 1.80]
4 Bayley PDI < ‐2 SD in survivors tested	1	90	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.30, 1.50]
5 Blindness	13	784	Risk Ratio (M‐H, Fixed, 95% CI)	0.78 [0.35, 1.73]
6 Blindness in survivors assessed	13	539	Risk Ratio (M‐H, Fixed, 95% CI)	0.77 [0.35, 1.67]
7 Deafness	8	565	Risk Ratio (M‐H, Fixed, 95% CI)	0.54 [0.22, 1.32]
8 Deafness in survivors assessed	8	362	Risk Ratio (M‐H, Fixed, 95% CI)	0.62 [0.26, 1.48]
9 Cerebral palsy	16		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
9.1 At 1 to 3 years	15	940	Risk Ratio (M‐H, Fixed, 95% CI)	1.10 [0.79, 1.54]
9.2 At latest reported age	16	919	Risk Ratio (M‐H, Fixed, 95% CI)	1.16 [0.82, 1.64]
10 Death before follow‐up in trials assessing cerebral palsy	16		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
10.1 At 1 to 3 years	15	940	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.65, 1.08]
10.2 At latest reported age	16	919	Risk Ratio (M‐H, Fixed, 95% CI)	0.82 [0.63, 1.07]
11 Death or cerebral palsy	16		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
11.1 At 1 to 3 years	15	940	Risk Ratio (M‐H, Fixed, 95% CI)	0.93 [0.77, 1.12]
11.2 At latest reported age	16	919	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.78, 1.15]
12 Cerebral palsy in survivors assessed	16		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
12.1 At 1 to 3 years	15	668	Risk Ratio (M‐H, Fixed, 95% CI)	1.08 [0.77, 1.50]
12.2 At latest reported age	16	628	Risk Ratio (M‐H, Fixed, 95% CI)	1.15 [0.81, 1.61]
13 Major neurosensory disability (variable criteria ‐ see individual studies)	9	719	Risk Ratio (M‐H, Fixed, 95% CI)	1.15 [0.86, 1.54]
14 Death before follow‐up in trials assessing major neurosensory disability (variable criteria)	9	719	Risk Ratio (M‐H, Fixed, 95% CI)	0.85 [0.64, 1.12]
15 Death or major neurosensory disability (variable criteria)	9	719	Risk Ratio (M‐H, Fixed, 95% CI)	1.02 [0.86, 1.21]
16 Major neurosensory disability (variable criteria) in survivors assessed	9	517	Risk Ratio (M‐H, Fixed, 95% CI)	1.06 [0.81, 1.40]
17 Abnormal neurological exam (variable criteria ‐ see individual studies)	4	200	Risk Ratio (M‐H, Fixed, 95% CI)	1.81 [1.05, 3.11]
18 Death before follow‐up in trials assessing abnormal neurological exam (variable criteria)	4	200	Risk Ratio (M‐H, Fixed, 95% CI)	0.57 [0.33, 0.99]
19 Death or abnormal neurological exam (variable criteria)	4	200	Risk Ratio (M‐H, Fixed, 95% CI)	0.96 [0.71, 1.31]
20 Abnormal neurological exam (variable criteria) in survivors assessed	4	145	Risk Ratio (M‐H, Fixed, 95% CI)	1.62 [0.96, 2.73]
21 Rehospitalisation	1	118	Risk Ratio (M‐H, Fixed, 95% CI)	1.15 [0.79, 1.66]
22 Rehospitalisation in survivors seen at follow‐up	1	92	Risk Ratio (M‐H, Fixed, 95% CI)	0.98 [0.72, 1.34]