Comparison 10. Influenza vaccines versus no vaccination: cohort studies in community‐dwellers ‐ risk groups.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
10.1 Influenza	1	6423	Risk Ratio (M‐H, Random, 95% CI)	0.40 [0.14, 1.17]
10.1.1 Epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.1.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.1.3 Non‐epidemic year ‐ vaccine matching	1	6423	Risk Ratio (M‐H, Random, 95% CI)	0.40 [0.14, 1.17]
10.1.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.2 Pneumonia	1	6423	Risk Ratio (M‐H, Random, 95% CI)	1.22 [0.76, 1.94]
10.2.1 Epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.2.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.2.3 Non‐epidemic year ‐ vaccine matching	1	6423	Risk Ratio (M‐H, Random, 95% CI)	1.22 [0.76, 1.94]
10.2.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.3 Hospitalisation for influenza or pneumonia	1	45932	Risk Ratio (M‐H, Random, 95% CI)	0.74 [0.63, 0.86]
10.3.1 Epidemic year ‐ vaccine matching	1	45932	Risk Ratio (M‐H, Random, 95% CI)	0.74 [0.63, 0.86]
10.3.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.3.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.3.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.4 Hospitalisation for any respiratory disease	2	189004	Risk Ratio (M‐H, Random, 95% CI)	0.85 [0.80, 0.92]
10.4.1 Epidemic year ‐ vaccine matching	2	189004	Risk Ratio (M‐H, Random, 95% CI)	0.85 [0.80, 0.92]
10.4.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.4.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.4.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.5 Deaths from respiratory disease	1	142464	Risk Ratio (M‐H, Random, 95% CI)	0.92 [0.86, 0.98]
10.5.1 Epidemic year ‐ vaccine matching	1	142464	Risk Ratio (M‐H, Random, 95% CI)	0.92 [0.86, 0.98]
10.6 All deaths	3	68032	Risk Ratio (M‐H, Random, 95% CI)	0.39 [0.16, 0.97]
10.6.1 Epidemic year ‐ vaccine matching	1	2344	Risk Ratio (M‐H, Random, 95% CI)	0.13 [0.02, 0.92]
10.6.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.6.3 Non‐epidemic year ‐ vaccine matching	2	65688	Risk Ratio (M‐H, Random, 95% CI)	0.47 [0.17, 1.28]
10.6.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.7 Hospitalisation for heart disease	1	45932	Risk Ratio (M‐H, Random, 95% CI)	0.92 [0.83, 1.03]
10.7.1 Epidemic year ‐ vaccine matching	1	45932	Risk Ratio (M‐H, Random, 95% CI)	0.92 [0.83, 1.03]
10.7.2 Epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.7.3 Non‐epidemic year ‐ vaccine matching	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.7.4 Non‐epidemic year ‐ vaccine matching absent or unknown	0	0	Risk Ratio (M‐H, Random, 95% CI)	Not estimable
10.8 Combined outcome: all deaths or severe respiratory illness	2	146248	Risk Ratio (M‐H, Random, 95% CI)	0.60 [0.49, 0.74]
10.8.1 Epidemic year ‐ vaccine matching	1	54438	Risk Ratio (M‐H, Random, 95% CI)	0.54 [0.49, 0.60]
10.8.2 Epidemic year ‐ vaccine matching absent or unknown	1	91810	Risk Ratio (M‐H, Random, 95% CI)	0.67 [0.61, 0.72]