Table 4.

Association between multiple vaccines during deployment controlled for three additional potential confounders. Figures are odds ratios (95% confidence intervals) for multisymptom illness

No of vaccines during deployment	Correction
	All vaccines received	All vaccines received, No of years in military	All vaccines received, No of years in military, reported side effects	All vaccines received, No of years in military, reported side effects, month of deployment, total duration in theatre
0/1	1.0	1.0	1.0	1.0
2	2.8 (1.5 to 5.2)	2.5 (1.5 to 4.2)	1.9 (1.1 to 3.2)	2.9 (1.5 to 5.6)
3	3.5 (1.8 to 6.8)	2.6 (1.5 to 4.3)	2.0 (1.2 to 3.3)	2.4 (1.3 to 4.7)
4	3.5 (1.8 to 6.8)	2.3 (1.5 to 3.6)	1.7 (1.1 to 2.7)	2.5 (1.4 to 4.6)
⩾5	8.6 (3.5 to 21.0)	5.5 (2.7 to 11.1)	4.1 (2.1 to 8.2)	7.3 (3.1 to 17.5)
	χ2=21.4 (<0.0001)*	χ2=26.7 (<0.0001)*	χ2=14.0 (0.0002)*	χ2=17.3 (<0.0001)*

^*Test for trend with P value.