Table 3 Risk of negative or perforated appendectomy adjusted for confounders by logistic regression

Rural living

1.42 (1.16, 1.76)**

1.28 (1.01, 1.61)**

1.11 (0.96, 1.28)

Availability of surgeon in the region

0.64 (0.52, 0.79)***

0.66 (0.52, 0.83)**

0.96 (0.83, 1.10)

Low family income

0.99 (0.98, 1.00)

0.98 (0.97, 0.99)*

0.99 (0.99, 1.00)

0.99 (0.98, 0.99)*

Home language: English

1.01 (1.00, 1.02)

1.00 (0.99, 1.01)

Below high school education §

1.01 (0.97, 1.06)*

1.00 (0.97, 1.03)

Ultra-sound use

0.99 (0.95, 1.02)

0.98 (0.96, 1.01)

0.83 (0.72, 0.95)*

Immigrants

0.87 (0.69, 1.09)

1.01 (0.87, 1.18)