Fig. 2

Percentage of surgeries (1700 – 0700 hours) performed after hours over the study period. For A, B, C, and D, the interrupted time series analysis is displayed on the right. Red solid line represents the fitted model calculated by segmented regression. The red dashed line represents the counterfactual (i.e. if no policy change occurred). The grey shaded area represents the 3-month “transition” period allowed for policy implementation. The grey shaded area represents the “transition” period. There was no statistically significant difference between the fitted model and counterfactual scenario for any surgery type (Table 3).