Table 2.

Ambulance PEWS sensitivity, specificity and positive and negative predictive value with respect to emergency department outcome.

PEWS	Sensitivity % (95% CI)	Specificity % (95% CI)	PPV % (95% CI)	NPV % (95% CI)
a) ED outcome: admission
1	6.80	83.33	38.89	36.42
	2.78–13.50	72.13–91.38	17.30–64.25	28.75–44.64
2	8.72	75.00	72.20	9.93
	4.73–14.46	50.9–91.34	46.52–90.31	5.67–15.50
3	9.64	33.30	88.89	0.66
	5.61–15.18	0.84–90.57	65.29–98.62	0.02–3.63
≥ 4	10.12	0.00	94.44	0.00
	6.01–15.71	0.00–97.50	72.71–99.86	0.00–2.41
b) ED outcome: GP referral
1	15.53	78.79	53.33	37.42
	9.15–24.00	66.98–87.89	34.33–71.66	29.36–46.01
2	18.12	85.00	90.00	12.23
	12.29–25.26	62.11–96.79	73.47–97.89	7.29–18.86
3	17.47	66.67	96.67	1.44
	12.02–24.12	9.43–99.16	82.78–99.92	0.17–5.10
≥ 4	17.86	100.00	100.00	0.72
	12.38–24.50	2.50–100.00	88.42–100.00	0.02–3.94
c) ED outcome: discharged home
1	62.14	45.45	64.0	43.48
	52.04–71.51	33.14–58.19	53.79–73.36	31.58–55.96
2	61.07	55.0	91.0	15.94
	52.75–68.95	31.53–76.94	83.60–95.80	8.24–26.74
	52.75–68.95	31.53–76.94	83.60–95.80	8.24–26.74
	52.75–68.95	31.53–76.94	83.60–95.80	8.24–26.74
	52.75–68.95	31.53–76.94	83.60–95.80	8.24–26.74
3	60.24	100.0	100.0	4.35
	52.37–67.74	29.24–100.00	96.38–100.00	0.91–12.18
≥ 4	59.52	100.0	100.0	1.45
	51.69–67.02	2.50–100.00	96.38–100.00	0.04–7.81

NPV: negative predictive value; PPV: positive predictive value.