Table 1

Parameter estimates and p values of the segmented regression models to predict daily CT turnaround times (A) and daily CT utilisation rate over time (B)

VariableCoefficientP value
(A) Daily CT turnaround times
Weekdays, 17:00–20:00
Time to protocol
 Background time trend0.00730.659
 Intervention effect−8.71570.098
 Intervention time-effect−0.02910.516
Time to scan
 Background time trend0.00550.866
 Intervention effect−15.7200.130
 Intervention time-effect0.05400.541
Weekends, 08:00–20:00
Time to protocol
 Background time trend0.03350.455
 Intervention effect0.71740.953
 Intervention time-effect−0.04570.504
Time to scan
 Background time trend0.11550.362
 Intervention effect−18.4340.592
 Intervention time-effect−0.06500.997
(B) Daily CT utilisation rate
Weekdays, 24 hours
 Background time trend0.00210.001
 Intervention effect−0.00410.984
 Intervention time-effect0.00210.275
Weekdays, 17:00–20:00 only
 Background time trend0.00070.020
 Intervention effect−0.02050.829
 Intervention time-effect0.00150.058
Weekends, 24 hours
 Background time trend0.00550.001
 Intervention effect0.65080.167
 Intervention time-effect−0.01040.691
Weekends, 08:00–20:00 only
 Background time trend0.00330.008
 Intervention effect0.73220.032
 Intervention time-effect−0.01890.323
  • p values < 0.05 in bold.