|
Variable a)
|
Type
|
Estimate (95% CI)
|
IRR c)(95% CI)
|
P-value
|
|---|
|
Average number of children at home per census family
|
Linear (X) b)
|
0.22 (−0.20, 0.64)
|
1.24 (0.82, 1.89)
|
0.313
|
|
Quadratic (X^2)
|
1.69 (0.84, 2.53)
|
5.40 (2.32, 12.54)
|
<0.001
|
|
Average median family income
|
Categorical
|
Low (< CAD d) 65,000)
|
0.29 (0.11, 0.47)
|
1.34 (1.12, 1.61)
|
0.002
|
|
Medium (CAD 65,000 - 85,000)
|
Reference
|
-
|
-
|
|
High (> CAD 85,000)
|
0.22 (0.03, 0.40)
|
1.24 (1.03, 1.49)
|
0.020
|
|
Visible minority population proportion
|
Categorical
|
Low (2.1 - 29.4)
|
−0.16 (−0.35, 0.036)
|
0.85 (0.70, 1.04)
|
0.110
|
|
Medium (29.5 - 51.8)
|
Reference
|
-
|
-
|
|
High (51.9 - 93.4)
|
−0.27 (−0.44, -0.10)
|
0.76 (0.64, 0.91)
|
0.002
|
|
Intercept
|
-
|
-
|
−0.12 (−0.29, 0.05)
|
-
|
0.178
|
-
a) Dependent variable: Number of Salmonella Enteritidis infections by forward sortation area (FSA). Offset: natural log-transformed FSA-based expected number of cases. b) Each linear (continuous) variable was centered by substracting the mean value from each value. A quadratic term for the centered linear variable was introduced and kept in the model if it was significant. If the linear and quadratic terms were not statistically significant, the variable was categorized into three equal groups (low, medium, and high). c) IRR: incidence rate ratio; CI: confidence interval. d) CAD: Canadian Dollar. Significant at P ≤ 0.05.
