Abstract P157: Factors Influencing Time-Dependent Quality Indicators for Suspected ACS Patients in the ED
Authors: France Dan , Levin Scott , Ding Ru , Hemphill Robin , Han Jin , Russ Stephan , Aronsky Dominik , Weinger Matthew B 
Published: March 2022

Background:
Rapid risk stratification and timely treatment are critical to favorable outcomes for acute coronary syndrome (ACS) patients. This study examines five time-dependent quality indicators (QIs) for unstable angina (UA) / non-ST elevation (NSTEMI) patients in the ED. Our objective was to determine patient and system factors that influence QIs (see Table1) for timeliness for ED UA/NSTEMI patients.

Methods:
A retrospective, cohort study was conducted at an academic medical center ED over a 2 year period. The cohort consisted of all patients (N=12,544) aged 24 years or older suspected of having ACS as defined by receiving an electrocardiogram (ECG) and at least one cardiac biomarker test. Cox regression was used to model the effects of patient characteristics, ancillary service utilization, staffing provisions, equipment availability and metrics characterizing ED and hospital crowding on time-dependent QIs.

Results:
UA/NSTEMI patient QI times and percentage adherence to defined performance standards are displayed in Table 1. Table 2 shows the factors that most influenced ED performance on each QI, a description of how each factor changed, and the resultant change in QI time interval. Average change in indicator time was calculated using the full Cox regression model created for each indicator, thus adjusting for all other significant factors.

Quality Indicator
Definition
Performance Standard
Time: Median (IQR) min
% Adherence

1. ECG read out time (Suspected of UA/NSTEMI - ECG and Biomarker)
Arrival time to ECG read out time
< = 10 min
13 (7 - 32)
42%

2. Lab turn-around-time
Physician biomarker order to lab report time
< = 60 min
70 (53 - 96)
37%

3. Therapeutic  __turn-around-time (overall)
Physician biomarker order to first anti-ischemic medication administration
Not defined
30 (14 - 66)
–

3b. Therapeutic  __turn-around-time (Anti-platelet))
Physician biomarker order to first anti-ischemic medication administration
Not defined
173 (71 - 317)
–

3c. Therapeutic  __turn-around-time (Anti-thrombin)
Physician biomarker order to first anti-ischemic medication administration
Not defined
30 (14 - 65)
–

4. Boarding time
Disposition decision time to inpatient admit time for admitted patients
< = 120 min
198 (97 - 496)
32%

5. ED length of stay
Arrival time to discharge (disposition decision for inpatients)
Not defined
247 (156 - 392)
–

Quality Indicator
Factor
Change in Factor
Hazard Ratio
Median Ä in Minutes (%)

1. ECG read out time
Chief Complaint  Chief Complaint  Acuity  Acuity
Non-chest pain related compared to chest pain  Chest pain related compared to chest pain  Level 1 compared to levels 3 to 5  Level 2 compared to levels 3 to 5
0.35  0.58  1.83  1.36
17.0  5.0  -2.4  -1.4

2. Lab turn-around-time
Cardiologist in ED  Time of Day  Time of Day  Point of Care Testing  Team Triage
Cardiologist present in ED compared to not present  Night compared to day  Evening compared to day  Point of care compared to standard lab  Team triage compared to not active
0.74  0.84  0.89  1.15  1.12
8.0  4.5  3.0  -3.0  -2.4

3. Therapeutic turn-around-time
Stress Test  Chief Complaint  Chief Complaint  Non-portable Chest  X-ray
Stress test prior to med administration compared to none  Non-chest pain related compared to chest pain  Chest pain related compared to chest pain  Non-portable chest X-ray prior to med administration compare to none
0.41  0.60  0.72  0.82
163.8  67.7  39.2  20.5

4. ED Boarding Time
Med Administration  Patient Insurance  Patient Insurance  Time of Day  Patient Insurance  Telemetry Occupancy  Time of Day  Acuity  Cardiology consult placeHoliday  Portable Chest X-Ray  Acuity  Med Administration
Med administration before disposition compared to no med administration  Self pay compared to commercial  Medicaid compared to commercial  Night Compared to day  Medicare compared to commercial  10% increase in telemetry occupancy  Evening compared to day  Level 1 compared to levels 3 to 5  Consultant used compared to none  placeHoliday compare to non holiday  Portable Chest X-ray before disposition compared to no X-ray  Level 2 compared to levels 3 to 5  Med administration after disposition  Compared to no med administration
1.09  0.84  0.81  0.84  0.88  0.28  0.97  3.83  1.37  1.33  1.19  1.15  0.77
63.3  48.4  39.6  38.4  27.8  27.7  6.7  -135.5  -48.1  -44.1  -29.5  -24.1  -14.6

5. ED length of stay
Stress Test  Point of Care Testing  Age 45 - 54 Years  Age 35 - 44 Years  Chief Complaint  Time of Day  Admitted Chief Complaint  ED chest pain occupancy
Stress test prior to disposition decision compared to none  Point of care compared to standard lab  45 - 54 years compared to > 64 years  35 -44 years compared to > 64 years  Not chest pain-related compared to chest pain-related  Evening  Admitted compared to discharged  Chest pain-related compare to not related to chest pain Percent increase in ED chest pain/neurology load
0.36  0.78  0.81  0.81  0.87  0.88  1.70  1.11  1.01
171.0  30.2  26.0  25.2  17.6  15.0  -50.5  -10.7  -2.9

Conclusions:
The natural variability (not amenable to change) of patient and clinical factors and the artificial variability created by man-made processes and systems (amenable to change) both significantly influenced QI times for our ED UA/NSTEMI cohort. ECG time was the only QI influenced solely by patient factors.