A prospective cohort study of patients in Maine with sciatica and lumbar spinal stenosis treated surgically and nonsurgically.
Summary of Background Data
In 1987, the Quebec Task Force on Spinal Disorders proposed a diagnostic classification to help make clinical decisions, evaluate quality of care, assess prognosis, and conduct research.
To assess the Quebec Task Force classification's ability to stratify patients according to severity and treatment at baseline, and to assess changes over time in health-related quality of life, including symptoms, functional status, and disability.
Five hundred sixteen patients participating in the Maine Lumbar Spine Study who completed baseline and 1-year follow-up evaluations were classified successfully according to the Quebec Task Force classification. Patient characteristics and treatments were compared across Quebec Task Force classification categories. Changes in health-related quality of life over 1 year were assessed according to Quebec Task Force classification category and type of treatment.
Among patients with sciatica (n = 370), higher Quebec Task Force classification categories (from 2, pain radiating to the proximal extremity, to 6, sciatica with evidence of nerve root compression) were associated with increased severity of symptoms at baseline. There was no association between Quebec Task Force classification and baseline functional status. Quebec Task Force classification was associated strongly with the likelihood of receiving surgical treatment (P ≤ 0.005). Among patients with sciatica treated nonsurgically, improvement at 1 year in back-specific and generic physical function increased with higher Quebec Task Force classification category (P ≤ 0.05). Only a nonsignificant trend was observed for surgically treated patients. Patients with lumbar spinal stenosis (Quebec Task Force classification 7, n = 131) had baseline features and outcomes distinct from patients with sciatica.
For patients with sciatica, the Quebec Task Force classification was highly associated with the severity of symptoms and the probability of subsequent surgical treatment. Nonsurgically treated patients in Quebec Task Force classification categories reflecting nerve root compression had greater improvement than those with pain symptoms alone. Among surgical patients, the Quebec Task Force classification was not associated with outcome. These results provide validation for the classification and its wider adoption. Nonetheless, improved diagnostic classifications are needed to predict outcomes better in patients with sciatica who undergo surgery.