A Basic Data Collection Plan

Evaluation of OHCA survival can begin with tracking of just a few critical pieces of information. The most meaningful performance measurement is the rate of survival to hospital discharge for bystander-witnessed, out-of-hospital cardiac arrests that occurred prior to the arrival of EMS, and for which the first recorded cardiac rhythm is ventricular fibrillation. This group of patients serves as the benchmark. They generally have well-documented times of collapse and hearts with an opportunity to respond to rapid defibrillation. They are most likely to survive if the system is working optimally.

Minimum Data Elements Needed to Calculate Witnessed VF Survival Rates


  • Cases of bystander-witnessed sudden cardiac arrest, prior to EMS arrival
  • Cases with the first recorded rhythm ventricular fibrillation (VF)
  • Hospital outcome data to indicate survival status at hospital discharge
  • Patient care identifiers to allow linkage of prehospital data and hospital outcome: name, date of birth, EMS call identifier, date of incident, hospital name

Download xls Spreadsheet: Survival Calculator

If your EMS system serves a population of 50,000 or less, there are likely fewer than 25 cardiac arrests per year in your system and fewer than 10 bystander-witnessed VF events.

In this case, it may be feasible to enter basic registry items in a spreadsheet format. Go to www.heartrescueproject.com for a link to the VF spreadsheet you can download from the website.