# Table 2 Results of univariable negative binomial regression models (n = 846 cases from 153 FSAs)

Variable a)

Type

IRR c)(95% CI)

P - value

Average number of children at home per census family

Linear (X)

1.03 (0.71, 1.50)

0.881

4.45 (1.81, 10.92)

0.001

Average number of persons per census family

Linear (X)

0.89 (0.64, 1.25)

0.515

4.47 (1.82, 10.98)

0.001

Average number of rooms per home

Linear (X)

0.97 (0.91, 1.04)

0.398

1.08 (1.03, 1.13)

0.002

Immigrant population proportion

Linear (X)

0.99 (0.99, 1.00)

0.284

0.99 (0.99, 0.99)

0.014

Average median family income

Categorical

1.30 (1.08, 1.57)

0.005

Reference

-

1.31 (1.08, 1.58)

0.006

Proportion of university graduates of persons between 25 to 64 years of age

Categorical

Low (10.4 - 28.6)

0.93 (0.77, 1.12)

0.446

Medium (28.7 – 40.0)

Reference

-

High (40.4 – 72.5)

0.95 (0.78, 1.16)

0.640

Unemployment rate of persons 15 years of age or older

Categorical

Low (0 - 6.0)

1.06 (0.87, 1.29)

0.544

Medium (6.1 - 7.5)

Reference

-

High (7.6 - 11.0)

1.08 (0.89, 1.32)

0.423

Visible minority population proportion

Categorical

Low (2.1 - 29.4)

0.78 (0.64, 0.94)

0.009

Medium (29.5 - 51.8)

Reference

-

High (51.9 - 93.4)

0.77 (0.64, 0.92)

0.004

1. 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. 