Table 2 Efficacy and effectiveness of influenza vaccination according to different outcomes: crude results
VAC | UNVAC | RR | 95% Cl | ||
Number of GPs with a respiratory tract infection | 2002 | 37/66 (56.1%) | 21/35 (60%) | 0.93 | 0.66 – 1.32 |
2003 | 48/96 (50%) | 19/40 (47.5%) | 1.05 | 0.72 – 1.54 | |
2002–2003 | 85/162 (52.5%) | 40/75 (53.3%) | 0.98 | 0.76 – 1.27 | |
Number of GPs with a respiratory tract infection and positive nose and throat swabs | 2002 | 3/66 (4.5%) | 2/35 (5.7%) | 0.78 | 0.13 – 4.94 |
2003 | 11/96 (11.5%) | 9/40 (22.5%) | 0.51 | 0.23 – 1.13 | |
2002–2003 | 14/162 (8.6%) | 11/75 (14.7%) | 0.59 | 0.28 – 1.24 | |
Number of GPs with a respiratory tract infection and a 4-fold hemagglutination-inhibition antibody titre rise | 2002 | 2/59 (3.4%) | 4/33 (12.1%) | 0.28 | 0.05 – 1.45 |
2003 | 3/36 (8.3%) | 9/36 (25%) | 0.33 | 0.10 – 1.13 | |
2002–2003 | 5/95 (5.3%) | 13/69 (18.8%) | 0.28 | 0.10 – 0.75 | |
Number of GPs with a respiratory tract infection and positive swab or 4-fold hemagglutination-inhibition antibody titre rise | 2002 | 4/59 (6.8%) | 6/33 (15.2%) | 0.45 | 0.13 – 1.55 |
2003 | 7/36 (19.4%) | 13/36 (36.1%) | 0.54 | 0.24 – 1.19 | |
2002–2003 | 11/95 (11.6%) | 18/69 (26.1%) | 0.44 | 0.22 – 0.88 |