Four studies met the inclusion criteria (n=741 with lumbar spinal stenosis). All studies recruited consecutive patients. The authors stated that studies were prone to selection and incorporation biases. One study used a consensus diagnosis of multiple expert spine clinicians, two used blinded examiners and two used patient reported data.
Lower extremity pain: The likelihood of lumbar spinal stenosis increased in individuals over 70 years (LR 2.0, 95% CI 1.6 to 2.5) and in individuals younger than 60 years (LR 0.40, 95% CI 0.29 to 0.57). Concomitant orthopaedic problems such as osteoarthritis, inflammatory arthritis and fractures increased the likelihood of lumbar spinal stenosis (LR 2.0, 95% CI 1.2 to 3.5).
Symptoms: The symptoms that most increased the likelihood of lumbar spinal stenosis were: no pain when seated (LR 7.4, 95% CI 1.9 to 30); unexplained urinary disturbance (LR 6.9, 95% CI 2.7 to 17); improvement of symptoms when bending forward (LR 6.4, 95% CI 4.1 to 9.9); presence of bilateral buttock or leg pain (LR 6.3, 95% CI 3.1 to 13); and neurogenic claudication (LR 3.7, 95% CI 2.9 to 4.8). Absence of neurogenic claudication decreased the likelihood of lumbar spinal stenosis (LR 0.23, 95% CI 0.17 to 0.31).
Clinical examination: A score of 7 or higher on a diagnostic support tool that included history and examination findings increased the likelihood of lumbar spinal stenosis (LR 3.3, 95% CI 2.7 to 4.0); a score lower than 7 made the diagnosis less likely (LR 0.10, 95% CI 0.06 to 0.16).