Table 3

Relative risk and 95% confidence interval according to mussels consumption: stratified analysis.

No. Exposed

No. Cases

Attack Rate (%)

Relative Risk

95% Confidence Interval

p value

eating raw mussels = "yes" (n = 80) eating cooked mussels

70

59

84.3

0.84

0.76

0.93

>0.05

eating raw mussels = "no" (n = 59) eating cooked mussels

42

30

71.4

3.04

1.26

7.30

<0.001

Summary Risk Ratio

1.38

1.00

1.91

Prato et al. BMC Infectious Diseases 2004 4:37   doi:10.1186/1471-2334-4-37