Comparison 13. Legislation versus no legislation ITS.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 NSI‐ change in level	3		Effect Size (Random, 95% CI)	Subtotals only
1.1 Interruption	2		Effect Size (Random, 95% CI)	‐6.15 [‐7.76, ‐4.54]
1.2 Gradual introduction	1		Effect Size (Random, 95% CI)	0.80 [0.41, 1.19]
2 NSI‐ Change in slope	3		Effect Size (Random, 95% CI)	Subtotals only
2.1 Interruption	2		Effect Size (Random, 95% CI)	‐0.94 [‐1.97, 0.09]
2.2 Gradual introduction	1		Effect Size (Random, 95% CI)	0.5 [0.36, 0.64]