Table 1 Estimated sensitivity and specificity of individual key indicator symptoms reported in EMS calls, compared to call handlers’ performance

Call handlers’ performance

(65.8–79.1)

(99.3–99.6)

 Unconscious

(80.2–90.5)

(89.0–96.2)

 Not Breathing

(50.6–65.0)

(94.4–99.1)

 Ineffective Breathing

(50.0–64.5)

(53.2–67.4)

 Collapse

(36.6–51.1)

(78.8–89.2)

 Breathing Yes/Effective

(23.9–37.6)

(11.8–22.6)

 Change in Colour

(22.9–36.0)

(75.6–86.8)

 Noisy Breathing

(19.8–32.8)

(87.4–95.3)

 Died

(16.2–28.6)

(96.9–99.9)

 Mouth/Vomit

(13.4–24.9)

(84.2–93.2)

 Conscious

(11.2–22.4)

(14.3–26.0)

 Eyes open/Staring

(11.0–21.8)

(93.9–98.8)

 Cool/Clammy/Cold

(10.7–21.6)

(71.3–83.6)

 Reduced or Fluctuating Consciousness

(10.3–20.9)

(73.2–84.9)

 Sudden Onset/Deterioration

(9.0–19.1)

(92.4–98.3)

 Major Trauma/Haemorrhage

(8.9–19.2)

(91.6–97.8)

 Serious/Urgent Problem

(6.3–15.6)

(93.9–98.8)

 Cardiac Symptoms/Disease¹

(4.4–12.4)

(79.5–89.9)

 No Pulse/Output

(4.0–11.7)

(97.1–100)

 Bystander resuscitation²

(3.6–11.0)

(99.9–100)

 Uncoordinated Movement

(3.7–11.2)

(93.7–98.8)

 Seizure-like Activity

(3.6–11.1)

(95.4–99.4)

 Unknown or Non-specific Problem

(2.4–9.1)

(87.6–95.6)

 Abnormal Pulse/Heart Rate

(1.2–6.8)

(94.5–99.4)

 Stroke-like Symptoms

(1.1–6.2)

(92.2–98.3)

 Self-harm

(0.6–5.5)

(96.8–100)

 Psychiatric Symptoms

(0.5–4.4)

(94.0–98.9)

 Death Imminent

(0.0–2.7)

(97.0–100)

 Drug/Alcohol use

(0.0–2.8)

(89.6–96.8)