Table 3.

Progression criteria (published in protocol paper [17])

GREEN; proceed to definitive study—GO	AMBER; consider protocol amendments to improve criteria	RED; do not proceed to main trial—STOP
≥ 70% of callers with smartphones agreeing and able to activate video livestreaming	≥ 50% of callers with smartphones agreeing and able to activate video livestreaming	< 50% of callers with smartphones agreeing and able to activate video livestreaming
≥ 50% of requests to activate video livestreaming resulting in footage being viewed	≥ 30% but < 50% of requests to activate video livestreaming resulting in footage being viewed	< 30% of requests to activate video livestreaming resulting in footage being viewed
Air Ambulance (HEMS) stand-down rate reducing by ≥ 10% and/or change in dispatch decision as a result of live streamed footage confirmed as being appropriate in ≥ 10% cases	Air Ambulance stand-down rate reducing by ≥ 5% and/or change in dispatch decision as a result of live streamed footage confirmed as being appropriate in ≥ 5% cases	No change in Air Ambulance stand-down rate and/or change in dispatch decision as a result of live streamed footage
Rates of psychological harm (based on the survey measures) not significantly greater in 999 callers using video livestreaming compared to those not; and no significant difference in change to psychological harm over time in staff (CCPs, HEMS dispatchers, Research Paramedics) compared to change in staff in a comparison EOC not using video livestreaming/streamed from scene footage	–	Evidence of significantly greater harm in either 999 callers or EOC staff using video livestreaming compared to EOC not using video livestreaming