Prognosis of Patients With Neuropathic Low Back-Related Leg Pain: An Exploratory Study Using Prospective Data From UK Primary Care.

This prospective cohort study investigates the prognosis of patients with neuropathic low back-related leg pain consulting in UK primary care. Data from 511 patients were collected using standardised baseline clinical examinations (including magnetic resonance imaging scan findings), self-report questionnaires at baseline, 4 months, 12 months, and 3 years. Cases of possible neuropathic pain (NP) and persistent-NP were identified using either of 2 definitions: 1) clinical diagnosis of sciatica, 2) self-report version of leeds assessment for neurological symptoms and signs (s-LANSS). Mixed-effects models compared pain intensity (highest of mean leg or mean back pain [0-10 Numerical Rating Scale]) over 3-years between persistent-NP versus non-persistent-NP based on 1) clinical diagnosis, 2) s-LANSS. Logistic regression examined associations between potential prognostic factors and persistent-NP at 4 months based on the 2 NP definitions. At 4-months, using both definitions: 1) approximately 4 out of 10 patients had persistent-NP, 2) mean pain intensity was higher for patients with persistent-NP at all follow-up points compared to those without, 3) only pain self-efficacy was significantly associated with persistent-NP (s-LANSS: OR .98, sciatica: .98), but it did not predict cases of persistent-NP in either multivariable model. Based on factors routinely collected from self-report and clinical examination, it was not possible to predict persistent-NP in this population. PERSPECTIVE: This study provides evidence that neuropathic back-related leg pain in patients consulting in primary care is not always persistent. Patients with persistent neuropathic pain had worse outcomes than those without. Neither leg pain intensity, pain self-efficacy nor MRI scan findings predicted cases of persistent neuropathic pain in this patient population.