| Study characteristics |
| Methods |
Authors investigated an outbreak in a nursing home in Honolulu, USA during the 1989 to 1990 influenza season; vaccination records, hospital records, resident records were reviewed. Follow‐up period was 15 December 1989 to 28 January 1990. Specimens for virus isolation were obtained from 9 ill residents, and paired sera specimens were obtained from 34 case and non‐case residents. |
| Participants |
39 nursing home residents with multiple chronic conditions (36 treated and 3 controls, all included in the analysis), 36 to 102 years (mean age 80 years) |
| Interventions |
Parenteral influenza vaccine; pneumococcal vaccine was also used. Vaccine strains matched circulating strains. |
| Outcomes |
Clinically defined ILI (fever 37.8 °C or greater + cough, coryza, or sore throat), laboratory‐confirmed influenza, pneumonia, deaths from ILI or pneumonia |
| Notes |
Amantadine was administered to all participants over a 1‐week period (January 4 to 12, 1990). The circulating strain was indistinguishable from the vaccine strain A/England/4/27/88. Lack of serologic evidence for other respiratory agents |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
B ‐ Unclear |
