Comparison 5. Subgroup by number of sessions.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Cessation at longest follow‐up	53		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
1.1 0 sessions	1	1023	Risk Ratio (M‐H, Fixed, 95% CI)	1.05 [0.69, 1.58]
1.2 1‐3 sessions	10	4032	Risk Ratio (M‐H, Fixed, 95% CI)	1.94 [1.60, 2.36]
1.3 4‐8 sessions	28	12163	Risk Ratio (M‐H, Fixed, 95% CI)	1.81 [1.64, 1.99]
1.4 Over 8 sessions	13	2270	Risk Ratio (M‐H, Fixed, 95% CI)	2.10 [1.65, 2.68]
1.5 Lung Health Study (over 8 sessions)	1	5887	Risk Ratio (M‐H, Fixed, 95% CI)	3.88 [3.35, 4.50]