| Study characteristics |
| Methods |
Retrospective cohort study conducted in Israel during the 2000 to 2001 influenza season, in the community. Data source was managed care organisation database. Follow‐up period was the entire influenza season. |
| Participants |
84,640 community‐dwelling elderly (36,596 treated and 48,044 controls included in the analysis), 65 years or older |
| Interventions |
Parenteral influenza vaccine. Vaccine strain probably matched the circulating strain (literature). |
| Outcomes |
Hospitalisation for any reason; deaths from all causes |
| Notes |
Very poor description of methods; no information about flu activity: probably not epidemic year. Data were presented by health status. Only deaths were included in the analysis. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
B ‐ Unclear |
