Impact of changes in the after-hours premium on emergency department visits between 2005/06 and 2015/16*
| Change in after-hours premium | All ED visits β (95% CI)† | Very urgent ED visits β (95% CI)† | Urgent ED visits β (95% CI)† | Less-urgent ED visits β (95% CI)† |
|---|---|---|---|---|
| Any timing | ||||
| 15% to 20% | −0.08 (−0.39 to 0.24) | 0.10 (> 0.00 to 0.20) | −0.24 (−0.42 to −0.05) | 0.06 (−0.14 to 0.26) |
| 20% to 30% | 3.08 (2.78 to 3.37) | 1.31 (1.20 to 1.42) | 1.99 (1.81 to 2.17) | −0.22 (−0.39 to −0.06) |
| Regular hours‡ | ||||
| 15% to 20% | 0.27 (0.10 to 0.43) | 0.04 (−0.02 to 0.09) | > 0.00 (−0.09 to 0.10) | 0.22 (0.11 to 0.34) |
| 20% to 30% | 1.26 (1.10 to 1.43) | 0.46 (0.41 to 0.52) | 0.89 (0.79 to 0.99) | −0.09 (−0.19 to 0.01) |
| After hours‡ | ||||
| 15% to 20% | −0.34 (−0.57 to −0.11) | 0.07 (−0.02 to 0.15) | −0.24 (−0.38 to −0.10) | −0.17 (−0.31 to −0.02) |
| 20% to 30% | 1.81 (1.60 to 2.02) | 0.84 (0.76 to 0.93) | 1.10 (0.97 to 1.23) | −0.13 (−0.25 to −0.02) |
Note: CI = confidence interval, ED = emergency department.
↵* Model of subcohort of patients with physicians using patient enrolment models (n = 201 594). Controlled for patient characteristics (patient age, low-income status, and comorbidity using aggregated diagnosis group score), and physician characteristics (physician age, physician age-squared, years since graduation, years since graduation-squared, physician sex, international medical graduation status, and group size) as well as the monthly dummy variable.
↵† β coefficients interpreted as the change in the number of ED visits per 1000 patients per month. For confidence intervals, standard errors were clustered at the patient and physician levels.
↵‡ Regular hours refers to 8 am to 5 pm weekdays; after hours refers to 5 pm to 8 am weekdays, and any time on weekends and statutory holidays.