Table 2

Case series analysis of asthma and COPD related outcomes in defined risk periods after influenza vaccination

Outcome	No of cases	No of outcomes	Incidence rate ratio (95% CI)
Outcome	No of cases	No of outcomes	Vaccination day	1–2 days*	3–14 days*
*After vaccination day.
**No events.
Any asthma diagnostic code
1991–1992	696	1385	14.93 (11.79 to 18.89)	0.76 (0.39 to 1.47)	0.88 (0.67 to 1.14)
1992–1993	616	1173	14.31 (11.02 to 18.59)	0.61 (0.27 to 1.37)	1.25 (0.98 to 1.61)
1993–1994	639	1239	12.12 (9.33 to 15.74)	1.16 (0.67 to 2.02)	0.96 (0.74 to 1.25)
Asthma exacerbation code
1991–1992	38	44	4.27 (0.56 to 32.62)	**	0.79 (0.18 to 3.49)
1992–1993	38	50	**	1.99 (0.26 to 15.20)	2.32 (0.95 to 5.65)
1993–1994	49	60	**	1.61 (0.21 to 12.20)	1.69 (0.67 to 4.26)
Oral corticosteroid prescription
1991–1992	352	971	5.01 (3.27 to 7.67)	0.87 (0.43 to 1.75)	0.74 (0.54 to 1.03)
1992–1993	329	824	8.24 (5.54 to 12.26)	1.04 (0.49 to 2.22)	1.18 (0.87 to 1.61)
1993–1994	354	848	4.06 (2.49 to 6.64)	0.96 (0.48 to 1.94)	0.79 (0.57 to 1.11)
Any COPD diagnostic code
1991–1992	416	744	11.41 (8.02 to 16.25)	0.31 (0.08 to 1.24)	0.61 (0.40 to 0.93)
1992–1993	339	599	14.23 (9.86 to 20.53)	0.58 (0.18 to 1.80)	1.00 (0.68 to 1.48)
1993–1994	345	632	7.38 (4.62 to 11.78)	0.55 (0.18 to 1.73)	1.07 (0.75 to 1.53)
COPD exacerbation code
1991–1992	61	86	2.25 (0.30 to 16.88)	**	0.19 (0.03 to 1.42)
1992–1993	62	89	16.86 (6.16 to 46.15)	**	0.74 (0.22 to 2.48)
1993–1994	68	90	2.63 (0.35 to 19.64)	**	1.20 (0.49 to 2.92)
Oral corticosteroid prescription
1991–1992	238	676	5.41 (3.28 to 8.92)	0.32 (0.08 to 1.27)	0.81 (0.55 to 1.18)
1992–1993	197	541	7.47 (4.62 to 12.06)	0.98 (0.40 to 2.38)	1.09 (0.75 to 1.58)
1993–1994	213	560	2.91 (1.43 to 5.91)	0.18 (0.03 to 1.29)	0.82 (0.55 to 1.22)