Table 2.

Subgroup analysis: prevalence of declared and actual public data sharing according to type of data and journal policy

Policy	Declared data sharing						Actual data sharing
	Sharing prevalence (%)	95% CI (%)	95% PI (%)	k	I2		Sharing prevalence (%)	95% CI (%)	95% PI (%)	k	I2 (%)
No data restrictions:
No policy	17*	0 to 59	NA	4	95		4*	0 to 95	NA	2	83
Encourage policy	17*	0 to 62	0 to 100	6	98		8*	0 to 48	NA	3	90
Mandatory policy	65*	36 to 88	2 to 100	5	99		33*	5 to 69	NA	3	93
Sequence data:
No policy	—	—	—	—	—		46*	0 to 100	NA	2	94
Encourage policy	—	—	—	—	—		57*	15 to 94	NA	2	0
Mandatory policy	—	—	—	—	—		67*	45 to 86	NA	3	70
Gene expression data:
No policy	23	11 to 42	NA	1	NA		—	—	—	—	—
Encourage policy	30	19 to 44	NA	1	NA		43	31 to 55	NA	1	NA
Mandatory policy	69*	0 to 100	NA	2	93		43*	0 to 100	NA	2	53
Trial data:
No policy	0*	0 to 46	NA	2	72		—	—	—	—	—
Encourage policy	0*	0 to 5	NA	3	24		—	—	—	—	—
Mandatory policy	55*	40 to 70	NA	2	0		56	33 to 77	NA	1	NA
Systematic review data:
No policy	5*	2 to 8	NA	2	0		0	0 to 4	NA	1	NA
Encourage policy	3*	0 to 100	NA	2	87		1	0 to 4	NA	1	NA
Mandatory policy	62*	0 to 100	NA	2	92		28	16 to 44	NA	1	NA

CI=confidence interval; PI=prediction interval; k=number of eligible meta-research studies; NA=not applicable.

^*Pooled estimate from random effects meta-analysis.