Table 4. Relative incidence estimates for the association between infections, influenza A(H1N1)pdm09 vaccination, seasonal influenza vaccination and Guillain-Barré syndrome.

	DK		FI		FR		NL		NO		SE		UK		Pooled
	RI	95% CI	RI	95% CI	RI	95% CI	RI	95% CI	RI	95% CI	RI	95% CI	RI	95% CI	RI	95% CI
Covariates
ILI	NA		NA		NA		10.5	3.0–36.3	30.6	8.6–108	NA		1.8	0.2–16.0	10.4	2.6–41.1
URTI	NA		NA		NA		13.0	4.3–39.2	17.7	6.2–34.7	NA		2.2	0.4–10.6	8.51	3.0–24.0
GI	NA		NA		NA		11.6	2.8–49.4	53.31	6.56–433	NA		2.3	0.2–22.6	11.9	2.5–55.6
Seasonal influenza vaccination	NA		NA		NA		1.2	0.4–4.0	5.5	1.6–18.9	NA		6.0	1.8–19.7	3.9	1.8–8.3
Any influenza A(H1N1)pdm09 vaccination
Unadjusted	7.7	1.1–54.4	1.6	0.5–5.4	6.4	1.0–40.4	2.7	1.3–5.9	3.9	1.6–9.3	4.8	2.1–11.1	3.3	0.3–36.5	3.5	2.2–5.5
Adjusted for calendar month	3.9	0.5–32.2	1.6	0.5–5.4	2.9	0.4–19.6	1.4	0.6–3.4	1.9	0.7–5.2	2.7	1.0–7.8	2.3	0.2–27.7	2.0	1.2–3.1
Adjustment effect any influenza A(H1N1)pdm09 vaccination in NL, NO, UK
Adjusted for calendar month only							1.4	0.6–3.4	1.9	0.7–5.2			2.3	0.2–27.7	1.7	0.8–3.4
Fully adjusted (month, ILI/URTI, GI)							1.2	0.5–3.3	1.5	0.5–4.6			1.5	0.1–23.1	1.4	0.7–2.8
Sensitivity analysis on influenza A(H1N1)pdm09 vaccination for contra-indication
Pseudolikelihood
1st dose	3.6	0.4–29.5	3.2	0.7–14.6	0.6	0.1–6.7	1.3	0.4–4.0	1.6	0.6–4.3	2.4	0.8–6.9	4.8	0.3–83.9	1.9	1.1–3.2
2nd dose	NA		NA		2.2	0.2–26.3	1.2	0.4–3.4	NA		NA		NA		1.3	0.5–3.4
Vaccinated cases only	NE		2.6	0.2–32.5	NE		1.2	0.2–8.3	1.6	0.3–7.9	2.5	0.4–16.0	NE		1.8	0.7–4.7

Abbreviations: NA: not available or not valid; NE = Not estimable due to small numbers or absence RI: relative incidence; ILI: influenza like illness; URTI: upper respiratory tract infection, GI: gastrointestinal Infection, UK: United Kingdom; NL: Netherlands; FR: France; SE: Sweden; FI: Finland, NO: Norway, DK: Denmark.