Table 3:

Impact of changes in the after-hours premium value on emergency department visits by timing, between 2002/03 and 2005/06*

Change in after-hours premiumAll 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)
Regular hours
 0% to 10%0.18 (0.01 to 0.35)0.21 (0.15 to 0.26)0.36 (0.26 to 0.46)−0.39 (−0.51 to −0.26)
 10% to 15%0.69 (0.51 to 0.86)0.17 (0.12 to 0.23)0.38 (0.28 to 0.49)0.13 (0.01 to 0.25)
After hours
 0% to 10%0.05 (−0.20 to 0.29)0.44 (0.36 to 0.52)0.48 (0.34 to 0.62)−0.87 (−1.03 to −0.72)
 10% to 15%0.59 (0.35 to 0.83)0.27 (0.18 to 0.35)0.49 (0.34 to 0.63)−0.16 (−0.32 to −0.02)
  • Note: CI = confidence interval, ED = emergency department.

  • * Controlling 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.