Comparison 2. HCWs offered vaccination versus HCWs offered no vaccination; three C‐RCTs (Carman 2000, Potter 1997, Lemaitre 2009) (adjusted analyses).

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Influenza	2	493	Risk Difference (M‐H, Random, 95% CI)	0.00 [‐0.03, 0.03]
1.1 Unvaccinated residents	1	160	Risk Difference (M‐H, Random, 95% CI)	0.01 [‐0.03, 0.05]
1.2 Vaccinated and unvaccinated residents	1	333	Risk Difference (M‐H, Random, 95% CI)	‐0.01 [‐0.06, 0.04]
2 Pneumonia	1	351	Risk Difference (M‐H, Random, 95% CI)	‐0.02 [‐0.06, 0.03]
2.1 Vaccinated residents	1	178	Risk Difference (M‐H, Random, 95% CI)	‐0.02 [‐0.08, 0.03]
2.2 Unvaccinated residents	1	173	Risk Difference (M‐H, Random, 95% CI)	‐0.01 [‐0.08, 0.06]
3 Admission to hospital for respiratory illness	1	1789	Risk Difference (M‐H, Random, 95% CI)	0.00 [‐0.02, 0.03]
3.1 Vaccinated and unvaccinated residents	1	1789	Risk Difference (M‐H, Random, 95% CI)	0.00 [‐0.02, 0.03]
4 Deaths from influenza or its complications	2		Risk Difference (M‐H, Random, 95% CI)	Totals not selected
4.1 Vaccinated residents	1		Risk Difference (M‐H, Random, 95% CI)	0.0 [0.0, 0.0]
4.2 Unvaccinated residents	1		Risk Difference (M‐H, Random, 95% CI)	0.0 [0.0, 0.0]
4.3 Vaccinated and unvaccinated residents	1		Risk Difference (M‐H, Random, 95% CI)	0.0 [0.0, 0.0]
5 Death from any cause	4		Risk Difference (M‐H, Fixed, 95% CI)	Totals not selected
5.1 Vaccinated residents	1		Risk Difference (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.2 Unvaccinated residents	1		Risk Difference (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
5.3 Vaccinated and unvaccinated residents	3		Risk Difference (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]