Table 4

Symptom attributes for vascular intermittent claudication

Attribute^*	Measure (95% CI)
Attribute^*	Sensitivity	Specificity	PLR	NLR
Single symptom attribute
Trigger
Walking (2)	0.96 (0.76–1.00)	0.10 (0.03–0.28)	1.10 (0.92–1.2)	0.43 (0.04–5.3)
Symptom onset
Predictable (2a)	0.87 (0.65–0.97)	0.37 (0.21–0.56)	1.37 (1.0–1.9)	0.36 (0.11–1.1)
Alleviator
Standing (3)	0.78 (0.56–0.92)	0.90 (0.72–0.97)	7.80 (2.6–23)^†	0.24 (0.11–0.53)^†
Nature
Numbness (8)	0.59 (0.37–0.79)	0.25 (0.11–0.45)	0.79 (0.52–12)	1.60 (0.80–3.3)
Cramping (9)	0.65 (0.43–0.83)	0.47 (0.29–0.65)	1.20 (0.78–1.9)	0.75 (0.40–1.9)
Burning pain (10)	0.47 (0.27–0.69)	0.38 (0.21–0.58)	0.77 (0.46–1.3)	1.37 (0.83–2.3)
Weakness (11)	0.41 (0.21–0.63)	0.57 (0.37–0.75)	0.95 (0.49–1.8)	1.00 (0.69–1.5)
Location
Calves (6)	0.78 (0.56–0.92)	0.73 (0.54–0.87)	2.90 (1.6–5.5)^†	0.30 (0.13–0.66)^†
Time for relief
1–2 min (11a)	0.57 (0.35–0.76)	0.57 (0.38–0.74)	1.30 (0.76–2.2)	0.77 (0.46–1.3)
Constellation of symptom attributes
Alleviated with Standing (3), located in the calves (6)	0.65 (0.43–0.83)	0.97 (0.81–1.0)	20.00 (2.8–140)^†	0.36 (0.21–0.63)^†

CI = confidence interval; NLR = negative likelihood ratio; PLR = positive likelihood ratio.
↵* Numbers in brackets represent the corresponding question number in the questionnaire (see the Appendix, available at cma.ca/cjs).
↵† Numbers whose value represent clinical significance.