Comparison 9. Secondary outcome: lung cancer histology at different time points.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
9.1 Histology types at baseline	4		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
9.1.1 SCLC	4	59987	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.45, 1.57]
9.1.2 squamous cell carcinoma	4	59987	Risk Ratio (M‐H, Random, 95% CI)	1.47 [1.01, 2.13]
9.1.3 adenocarcinoma	4	59987	Risk Ratio (M‐H, Random, 95% CI)	2.81 [1.38, 5.71]
9.1.4 bronchoalveolar carcinoma	2	55904	Risk Ratio (M‐H, Random, 95% CI)	4.94 [2.41, 10.10]
9.1.5 other	4	59987	Risk Ratio (M‐H, Random, 95% CI)	1.32 [0.90, 1.94]
9.2 Histology at year 1	1		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
9.2.1 SCLC	1	3318	Risk Ratio (M‐H, Random, 95% CI)	2.00 [0.37, 10.89]
9.2.2 squamous cell carcinoma	1	3318	Risk Ratio (M‐H, Random, 95% CI)	0.83 [0.25, 2.72]
9.2.3 adenocarcinoma	1	3318	Risk Ratio (M‐H, Random, 95% CI)	2.66 [1.24, 5.71]
9.2.4 other	1	3318	Risk Ratio (M‐H, Random, 95% CI)	2.33 [0.60, 9.00]
9.3 Histology at follow‐up	7		Risk Ratio (M‐H, Random, 95% CI)	Subtotals only
9.3.1 SCLC	6	71281	Risk Ratio (M‐H, Random, 95% CI)	0.86 [0.74, 1.01]
9.3.2 mixed SCLC + NSCLC	1	4104	Risk Ratio (M‐H, Random, 95% CI)	0.14 [0.01, 2.76]
9.3.3 squamous cell carcinoma	6	71281	Risk Ratio (M‐H, Random, 95% CI)	1.04 [0.81, 1.32]
9.3.4 adenocarcinoma	7	75333	Risk Ratio (M‐H, Random, 95% CI)	1.49 [1.05, 2.10]
9.3.5 bronchoalveolar carcinoma	3	61610	Risk Ratio (M‐H, Random, 95% CI)	2.73 [1.96, 3.81]
9.3.6 other	7	75333	Risk Ratio (M‐H, Random, 95% CI)	0.87 [0.68, 1.11]