Table 4

Secondary attack rates at the individual level

n

Secondary infection in household contacts

SAR

(95% CI)

Univariate OR

(95% CI)

Multivariate OR

(95% CI)

Index oseltamivir usage from his/her onset

Within 1 day

29

0.09

(0.03, 0.17)

0.53

(0.20, 1.37)

0.57

(0.20, 1.62)

1-2 days

11

0.17

(0.00,0.33)

1.06

(0.30, 3.69)

1.11

(0.30, 4.11)

3+ days/No usage

95

0.14

(0.10, 0.19)

-

-

Household with adult index

37

0.10

(0.04, 0.17)

1.00

1.00

Household with child index

98

0.14

(0.10, 0.19)

1.48

(0.62, 3.51)

1.55

(0.58, 4.15)

Adult contact*

217

0.09

(0.05, 0.13)

-

-

Child contact*

173

0.20

(0.13, 0.27)

2.71

(1.47, 5.02)

2.79

(1.50, 5.20)

Household size (# of ppl)

≤ 3

48

0.11

(0.04, 0.20)

-

-

4

41

0.14

(0.07, 0.20)

1.26

(0.48, 3.30)

0.93

(0.32, 2.72)

≥ 5

46

0.14

(0.08, 0.20)

1.25

(0.48, 3.24)

0.74

(0.26, 2.10)

* Multivariable ORs adjusted for unknown age group for 21 contacts via multiple imputations with 10 imputations

Goldstein et al. BMC Infectious Diseases 2010 10:211   doi:10.1186/1471-2334-10-211