Comparison 11. Influenza vaccines versus no vaccination: cohort studies in community‐dwellers ‐ no risk groups.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
11.1 Influenza	1	11399	Risk Ratio (M‐H, Random, 95% CI)	0.57 [0.27, 1.17]
11.1.1 Epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.1.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.1.3 Non‐epidemic year ‐ vaccine matching	1	11399	Risk Ratio (M‐H, Random, 95% CI)	0.57 [0.27, 1.17]
11.1.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.2 Pneumonia	1	11399	Risk Ratio (M‐H, Random, 95% CI)	0.59 [0.37, 0.92]
11.2.1 Epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.2.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.2.3 Non‐epidemic year ‐ vaccine matching	1	11399	Risk Ratio (M‐H, Random, 95% CI)	0.59 [0.37, 0.92]
11.2.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.3 Hospitalisation for influenza or pneumonia	1	101619	Risk Ratio (M‐H, Random, 95% CI)	0.50 [0.40, 0.63]
11.3.1 Epidemic year ‐ vaccine matching	1	101619	Risk Ratio (M‐H, Random, 95% CI)	0.50 [0.40, 0.63]
11.3.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.3.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.3.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.4 Hospitalisation for any respiratory disease	2	376324	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.55, 1.27]
11.4.1 Epidemic year ‐ vaccine matching	2	376324	Risk Ratio (M‐H, Random, 95% CI)	0.84 [0.55, 1.27]
11.4.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.4.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.4.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.5 Deaths from respiratory disease	1	281424	Risk Ratio (M‐H, Random, 95% CI)	1.41 [1.31, 1.53]
11.5.1 Epidemic year ‐ vaccine matching	1	281424	Risk Ratio (M‐H, Random, 95% CI)	1.41 [1.31, 1.53]
11.6 All deaths	3	43821	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.33, 1.29]
11.6.1 Epidemic year ‐ vaccine matching	1	7047	Risk Ratio (M‐H, Random, 95% CI)	1.09 [0.26, 4.49]
11.6.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.6.3 Non‐epidemic year ‐ vaccine matching	2	36774	Risk Ratio (M‐H, Random, 95% CI)	0.59 [0.27, 1.30]
11.6.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.7 Hospitalisation for heart disease	1	101619	Risk Ratio (M‐H, Random, 95% CI)	0.79 [0.61, 1.01]
11.7.1 Epidemic year ‐ vaccine matching	1	101619	Risk Ratio (M‐H, Random, 95% CI)	0.79 [0.61, 1.01]
11.7.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.7.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.7.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
11.8 Combined outcome: all deaths or severe respiratory illness	2	135180	Risk Ratio (M‐H, Random, 95% CI)	0.62 [0.54, 0.70]
11.8.1 Epidemic year ‐ vaccine matching	1	68536	Risk Ratio (M‐H, Random, 95% CI)	0.65 [0.54, 0.78]
11.8.2 Epidemic year ‐ vaccine matching absent or unknown	1	66644	Risk Ratio (M‐H, Random, 95% CI)	0.58 [0.48, 0.71]