Table 3:
Characteristics of the clinical trial studies included in the meta-analysis to investigate the effect of influenza vaccine on the risk of all-cause mortality
| First author (Reference number) | Year | Country | Sample size | Mean age | Women, % | Hypertension, % | Diabetes Mellitus, % | Smoker, % | OR (95% CI) | Duration of follow-up | Jadad Scale (Score) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Govaert (29) | 1994 | Netherlands | 1838 | 65 | - | - | - | - | 1.97(0.49–7.84) | 5 months | 5 |
| FLUVACS (30) | 2004 | Argentina | 292 | 64.5 | 28 | 52 | 18 | 44 | 0.34 (0.17 – 0.71) | 24 months | 5 |
| FLUCAD (31) | 2008 | Finland | 658 | 60 | 26 | 67 | 20 | 18 | 1.06 (0.15 – 7.56) | 10 months | 5 |
| IVCAD (33) | 2009 | Iran | 266 | 54.7 | 33 | 83 | - | - | 0.97 (0.20 – 4.72) | 6 months | 4 |
| De Villiers (32) | 2009 | South Korea | 3242 | 69.5 | 33 | 57 | 26 | 17 | 1 (0.54 – 1.85) | 8 months | 5 |
| Phromminti kul(34) | 2011 | Thailand | 439 | 66 | 43 | 62 | 31 | 12 | 0.39 (0.14 – 1.12) | 24 months | 4 |
| Verhees (37) | 2019 | Netherlands | 2198 | 67 | 53 | 45 | 3 | 23 | 0.96 (0.87 – 1.07) | 24 months | 5 |
| Fröbert (35) | 2021 | Sweden, Denmark, Norway, Latvia, the United Kingdom, Czech Republic, Bangladesh, and Australia | 2532 | 60 | 18 | 49 | 21 | 35 | 0.59(0.39–0.90) | 12 months | 5 |
| Langley (36) | 2011 | North america | 4561 | 50 | 55 | - | - | - | 0.17(0.02–1.83) | 12 months | 5 |
| Loeb (28) | 2022 | India-China-Africa | 5129 | 57 | 51 | - | 23 | - | 0.91(0.81–1.02) | 12 months | 5 |