Table 3. Performance of sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and kappa for each symptom separately and the use of just one question for stroke confirmation.

Symptom	Limb weakness	Facial Weakness	Articulation problems	Sensorydisorders	Impaired vision	At least 1 question addressing stroke symptoms
Sensitivity ((%)	57.9	26.3	26.3	31.6	26.3	57.8
Specificity (%)	88.2	94.1	100.0	88.2	82.3	100
Positive predictive value (%)	84.6	83.3	100.0	75	62.5	100
Negative predictive value (%)	65.2	53.3	45.2	53.6	50.0	68.0
Positive likelihood ratio	4.9	4.5	+∞	2.7	1.5	+∞
Negative likelihood ratio	0.48	0.78	0.74	0.76	0.90	0.58
Kappa	0.45	0.20	0.25	0.19	0.08	0.57

Kappa = coefficient of concordance beyond chance.