Crude incidence rates and adjusted risk ratio (RR) of complications, failure-to-rescue and 30-day mortality.

Note: 30-day mortality and complications were similar between the peer groups, but failure-to-rescue was less like to occur in the peer groups of major metro- and non-metropolitan (RR = 0.78; 95%CI: 0.60–0.99), district group 1 (RR = 0.57, 95%CI: 0.34–0.94) and district group 2 (RR = 0.61, 95%CI: 0.41–0.90) than that in the peer groups of principal referral and ungrouped acute hospitals.
‡P = 0.053;
*P≤0.05;
§P = (linear 0.02; quadratic 0.007);
†P = 0.12.