Table 3.

Diagnostic Accuracy of History and Physical Examination

Test	Sensitivity (95% CI)	Specificity (95% CI)	Positive LR (95% CI)	Negative LR (95% CI)
Historical features
Age, y
Age >65 (vs ≤65)38	0.77 (0.64–0.89)	0.69 (0.53–0.85)	2.5 (1.4–4.2)	0.34 (0.19–0.61)
>7035a	NA	NA	2.0 (1.6–2.5)
<6035a	NA	NA	0.40 (0.29–0.57)
Comorbidities
Orthopedic disease36	0.18 (0.13–0.24)	0.91 (0.87–0.95)	2.0 (1.2–3.5)	0.90 (0.83–0.98)
Pain locations
Bilateral buttock or leg37	0.51 (0.40–0.62)	0.92 (0.87–0.97)	6.3 (3.1–13)	0.54 (0.43–0.68)
Pain below buttocks38	0.88 (0.79–0.98)	0.34 (0.18–0.51)	1.4 (1.0–1.8)	0.34 (0.13–0.88)
Thigh37	0.95 (0.90–1.0)	0.14 (0.07–0.21)	1.1 (1.0–1.2)	0.36 (0.12–1.1)
Gluteal37	0.84 (0.75–0.92)	0.05 (0.01–0.09)	0.88 (0.79–0.98)	3.3 (1.2–8.8)
Symptoms reproduced by specific actions
No pain when seated38	0.47 (0.32–0.61)	0.94 (0.85–1.0)	7.4 (1.9–30)	0.57 (0.43–0.76)
Burning sensation around the buttocks, Intermittent priapism associated with walking, or both35	0.06 (0.03–0.09)	0.99 (0.98–1.0)	7.2 (1.6–32)	0.95 (0.92–0.98)
Improvement when bending forward35	0.52 (0.45–0.58)	0.92 (0.88–0.95)	6.4 (4.1–9.9)	0.52 (0.46–0.60)
Neurogenic claudication35	0.82 (0.77–0.87)	0.78 (0.73–0.83)	3.7 (2.9–4.8)	0.23 (0.17–0.31)
Improve when seated38	0.51 (0.36–0.66)	0.84 (0.72–0.97)	3.3 (1.4–7.7)	0.58 (0.41–0.81)
Exacerbation when standing up35	0.68 (0.62–0.74)	0.70 (0.65–0.76)	2.3 (1.8–2.8)	0.46 (0.37–0.56)
Exacerbated while standing up36	0.92 (0.88–0.96)	0.21 (0.15–0.27)	1.2 (1.1–1.3)	0.38 (0.21–0.69)
Other symptoms
Urinary disturbance35	0.14 (0.09–0.19)	0.98 (0.96–1.0)	6.9 (2.7–17)	0.88 (0.83–0.93)
Numbness of perineal region35	0.05 (0.02–0.07)	0.99 (0.97–1.0)	3.7 (1.0–13)	0.97 (0.94–1.0)
Bilateral plantar numbness35	0.27 (0.21–0.33)	0.87 (0.83–0.92)	2.2 (1.4–3.2)	0.84 (0.76–0.92)
Treatment for symptoms needs to be repeated every year36	0.40 (0.33–0.47)	0.80 (0.75–0.86)	2.0 (1.5–2.8)	0.75 (0.65–0.86)
Wake up to urinate at night36	0.86 (0.81–0.91)	0.27 (0.21–0.33)	1.2 (1.1–1.3)	0.50 (0.33–0.78)
Physical examination
Provocative tests
No pain with flexion38	0.79 (0.67–0.91)	0.44 (0.27–0.61)	1.4 (1.0–2.0)	0.48 (0.24–0.96)
Symptoms induced by having patients bend forward35	0.18 (0.13–0.23)	0.63 (0.57–0.69)	0.48 (0.34–0.66)	1.3 (1.2–1.5)
Neuromuscular tests
Wide-based gait38	0.42 (0.27–0.57)	0.97 (0.91–1.0)	13 (1.9–95)	0.60 (0.46–0.78)
Abnormal Romberg test result38b	0.40 (0.25–0.54)	0.91 (0.81–1.0)	4.2 (1.4–13)	0.67 (0.51–0.87)
Vibration deficit38	0.53 (0.39–0.68)	0.81 (0.68–0.95)	2.8 (1.3–6.2)	0.57 (0.40–0.82)
Pinprick deficit38	0.47 (0.32–0.61)	0.81 (0.68–0.95)	2.5 (1.1–5.5)	0.66 (0.48–0.91)
Weakness38	0.47 (0.32–0.61)	0.78 (0.64–0.92)	2.1 (1.0–4.4)	0.69 (0.49–0.96)
Absent Achilles reflex38	0.47 (0.32–0.61)	0.78 (0.64–0.92)	2.1 (1.0–4.4)	0.69 (0.49–0.96)

Abbreviations: CI, confidence interval; LR, likelihood ratio; NA, not applicable.

^aMultilevel (ordinal) LR.

^bModified Romberg maneuver performed with patient’s feet together and eyes closed for 10 seconds; result abnormal if compensatory movements required to keep feet planted.