ECC Data Analysis & Reporting 3 — Questions and Answers
Question 1: A QI team wants to determine if a new dispatcher CPR protocol caused a statistically significant increase in bystander CPR rates. Which analysis is most appropriate?
- Descriptive statistics only
- Chi-square test comparing pre- and post-implementation proportions (Correct answer)
- Linear regression of monthly averages
- Kaplan-Meier survival analysis
Correct answer: Chi-square test comparing pre- and post-implementation proportions
A chi-square test compares proportions (rates) between two groups, making it appropriate for assessing whether bystander CPR rates changed significantly before and after an intervention.
Question 2: Which report format is required by the CARES (Cardiac Arrest Registry to Enhance Survival) registry for OHCA data submission?
- HL7 FHIR format exclusively
- Standardized Utstein-based data elements (Correct answer)
- ICD-10 coded diagnosis only
- Narrative free-text reports
Correct answer: Standardized Utstein-based data elements
CARES uses standardized Utstein-based data elements to ensure uniform, comparable cardiac arrest data collection across participating EMS agencies and hospitals.
Question 3: A run chart of monthly ROSC rates shows 8 consecutive data points above the median line. According to run chart rules, this most likely indicates:
- Random variation within normal limits
- A non-random signal suggesting a real process shift (Correct answer)
- Insufficient sample size to draw conclusions
- Measurement error in data collection
Correct answer: A non-random signal suggesting a real process shift
Eight or more consecutive points on the same side of the median is a standard run chart rule signaling a non-random shift in the process.
Question 4: When benchmarking STEMI reperfusion times, why must raw door-to-balloon times be adjusted before comparing hospitals?
- To account for differences in EHR software
- To control for case mix factors like transfer patients and off-hours presentations (Correct answer)
- Because CMS requires statistical adjustment for all metrics
- To eliminate outlier data points from the dataset
Correct answer: To control for case mix factors like transfer patients and off-hours presentations
Transfer patients and off-hours (nights/weekends) cases systematically inflate door-to-balloon times, so risk adjustment is needed for fair comparisons.
Question 5: Which statistical process control (SPC) chart is best suited for monitoring monthly cardiac arrest survival rates over time?
- Histogram
- P-chart (proportion chart) (Correct answer)
- X-bar and R chart
- Scatter plot
Correct answer: P-chart (proportion chart)
A P-chart monitors proportions (like survival rate) over time and includes control limits to distinguish common cause from special cause variation.
Question 6: An EMS medical director reviews data showing that CPR compression depth averages 45 mm across 200 resuscitations. According to 2020 AHA guidelines, this performance is:
- Optimal — within the recommended 50-60 mm range
- Suboptimal — below the recommended minimum depth of 50 mm (2 inches) (Correct answer)
- Excessive — risking rib fracture above 40 mm
- Acceptable for patients over 65 years of age
Correct answer: Suboptimal — below the recommended minimum depth of 50 mm (2 inches)
The 2020 AHA guidelines recommend adult compression depth of at least 2 inches (50 mm), so a 45 mm average falls below the recommended minimum.
Question 7: In post-cardiac arrest care audit, 'favorable neurological outcome' is most commonly defined using which standardized scale?
- Glasgow Coma Scale (GCS)
- NIHSS stroke scale
- Cerebral Performance Category (CPC) score 1 or 2 (Correct answer)
- Modified Rankin Scale score 0-1 only
Correct answer: Cerebral Performance Category (CPC) score 1 or 2
CPC 1 (good cerebral performance) and CPC 2 (moderate disability but independent) together define 'favorable neurological outcome' in most ECC and resuscitation registries.
ECC Data Analysis & Reporting 3
A QI team wants to determine if a new dispatcher CPR protocol caused a statistically significant increase in bystander CPR rates.
Which analysis is most appropriate?