| Study characteristics |
| Methods |
Prospective cohort study conducted in Stockholm, Sweden during the 1999 to 2000 influenza season, in the community. Data sources were vaccination database and discharge diagnoses database. Follow‐up period was December 1999 to November 2000. 23% of vaccinated received flu vaccine alone; 58% of vaccinated received flu and pneumococcal vaccine. 19% of vaccinated participants received pneumococcal vaccine alone. Only flu vaccinated were included in analysis. |
| Participants |
163,391 community‐dwelling elderly (29,346 treated and 134,045 controls were included in the analysis), 65 years or older |
| Interventions |
Parenteral influenza vaccine: A/Beijing/262/95; A/Sydney/5/97; B/Harbin/7/94. Vaccine strains matched the circulating strain. |
| Outcomes |
Hospitalisation from influenza (ICD‐X: J10.0, J10.1, J10.8, J11.0, J11.1, J11.8), in‐hospital deaths from influenza, hospitalisation from pneumonia (ICD‐X: J12‐ J18, J69.0, A48.1), in‐hospital deaths from pneumonia |
| Notes |
Vaccinated people had higher education, more underlying diseases, and smoked less. Circulating strain was A/Sydney (H3N2). The season was probably an epidemic one. 6% of the population lived in a nursing home. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
B ‐ Unclear |
