| Study characteristics |
| Methods |
Prospective cohort study conducted in Australia in 17 nursing homes during the 1983 influenza season. Follow‐up period was autumn to spring; blinded assessment of illness was performed. |
| Participants |
326 residents in 17 nursing homes (229 treated and 97 controls, all included in the analysis), 44 to 99 years old |
| Interventions |
Parenteral influenza vaccine: A/Victoria/186/82; A/Philippines/2/82; B/Singapore/222/79. Vaccine strains matched circulating strains. |
| Outcomes |
Laboratory‐confirmed influenza (4‐fold increase in antibody titre) |
| Notes |
Poor description of methods; part of another study. The circulating strain was A/Philippines/2/82. No information about flu activity |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
B ‐ Unclear |
