Table 1 ARIMA model specification for outcome measures “mean length of stay,” “mean mNEDOCS,” and “sum of exit block”

Estimate

SE

Significance

Length of stay

MA Lag 1

0.793

0.37

<0.001

  Expansion of the ED to 26 beds

Numerator Lag 0

−16.078

6.297

0.011

Denominator Lag 1

−0.685

0.261

0.009

  Influenza 2018–2019

Numerator Lag 0

8.222

3.373

0.015

  Admission

Numerator Lag 0

0.187

0.26

<0.001

Denominator Lag 1

0.375

0.108

<0.001

  Back pain

Numerator Lag 0

−0.363

0.125

0.004

  Ear, nose, throat, and eye problems

Numerator Lag 0

−0.347

0.094

<0.001

  Extremity problems

Numerator Lag 0

0.043

0.021

0.045

  Other presenting problems

Numerator Lag 0

−0.124

0.048

0.010

  Urgent (yellow/orange) triage category

Numerator Lag 0

0.058

0.029

0.044

  Daytime

Numerator Lag 0

−0.061

0.018

<0.001

mNEDOCS

MA Lag 1

0.611

0.048

<0.001

  Integration GPC

Numerator Lag 0

−12.021

3.929

0.002

  Expansion of the ED to 34 beds

Numerator Lag 1

−11.998

3.971

0.003

  Closure ED HMC AH

Numerator Lag 0

17.318

4.946

<0.001

Numerator Lag 1

12.610

4.946

0.011

Exit block

MA Lag 1

0.888

0.029

<0.001

  Closure of ICU at HMC BR

Numerator Lag 0

20.460

6.235

0.001

Numerator Lag 1

17.763

6.295

0.005

  Influenza 2018–2019

Numerator Lag 0

7.973

2.293

0.001

  Admission

Numerator Lag 0

0.144

0.019

<0.001

  Shortness of breath

Numerator Lag 0

0.089

0.033

0.007

  Unwell patient

Numerator Lag 0

−0.083

0.029

0.005

  Age 70 years and older

Numerator Lag 0

0.090

0.019

<0.001

  Daytime

Numerator Lag 0

−0.029

−2.614

0.009