METHODS: A 4-stage modified Delphi consensus method was used to engage 32 PEC experts from 12 Asian countries. Participants voted on 32 elements identified from a prior scoping review, focus group discussions, and survey. Each round of voting was conducted through an anonymous, web-based application and followed by face-to-face group discussions. The first two rounds aimed to answer, "Is the element important and feasible in a low resource setting?" The last two stages aimed to answer "Should this element be prioritized as core in the tool?" A thematic analysis of the recorded and transcribed discussions was used to identify participants' rationale for prioritization.

RESULTS: After four rounds of voting, 12 elements were identified as core elements: 1) dispatch assisted instructions, 2) protocols for screening, triage and destination, (3) medical direction, 4) standardized training programs, 5) minimum ambulance standards, 6) operational metrics, 7) quality assurance, 8) operational safety protools, 9) essential patient care documentation, 10) medical records management, 11) layperson awareness and education and 12) universal access emergency number. However, the participants decided to include all 32 elements in the tool grouped into broader categories by percent agreement for a tiered approach for early, intermediate, and advanced PEC systems. Rationales for prioritization included a need for focus on basic infrastructure and building resilience in resource-stretched systems.