Risk of admission to hospital among people with type 2 diabetes who received influenza vaccination relative to people who did not receive vaccination for the influenza season and summer between 2003/04 and 2009/10 (excluding 2008/09, when the outbreak of pandemic A(H1N1)pdm09 occurred)
| Outcome | Season* | Unadjusted model† | Adjusted model‡ |
|---|---|---|---|
| IRR (95% CI) | IRR (95% CI) | ||
| Hospital admissions for acute myocardial infarction | Influenza | 1.17 (1.01–1.36) § | 0.76 (0.62–0.93)¶ |
| Summer | 1.27 (1.13–1.44)** | 0.91 (0.77–1.08) | |
| Hospital admissions for stroke | Influenza | 1.07 (0.91–1.25) | 0.86 (0.69–1.07) |
| Summer | 1.44 (1.26–1.64)** | 1.13 (0.93–1.36) | |
| Hospital admission for heart failure | Influenza | 1.25 (1.14–1.38)** | 0.82 (0.72–0.93)¶ |
| Summer | 1.59 (1.45–1.74)** | 1.03 (0.91–1.16) | |
| Hospital admission for pneumonia/influenza | Influenza | 0.97 (0.89–1.05) | 0.76 (0.68–0.85)** |
| Summer | 1.19 (1.09–1.28)** | 0.89 (0.79–0.99)* | |
| All-cause death | Influenza | 0.87 (0.81–0.93)** | 0.52 (0.47–0.58)** |
| Summer | 1.14 (1.08–1.21)** | 0.67 (0.61–0.73)** |
Note: CI = confidence interval, IRR = incidence rate ratio.
↵* Influenza season was defined as the period from the onset to the end of the influenza season, with an additional 4 weeks to capture delayed complications. Summer was defined as May 1 to Aug. 31 for each cohort year.
↵† Models with vaccination status as the only predictor.
↵‡ Models are adjusted for age, sex, index of multiple deprivation quintile, number of comorbid conditions, duration of diabetes, body mass index, smoking status, systolic and diastolic blood pressure, serum cholesterol and glycated hemoglobin, use of lipid-lowering drugs, anticoagulants or antiplatelet drugs, antihypertensive drugs, insulin, oral antihyperglycemic drugs or immunosuppressive drugs, number of hospital admissions during previous year, history of pneumococcal vaccination, influenza vaccination during previous year and cohort year.
↵§ p ≤ 0.05.
↵¶ p ≤ 0.01.
↵** p ≤ 0.001.