Objectives: Determine whether the achievement of the centralization phenomenon on initial assessment of patients with low back pain (LBP) can be predicted by history and physical examination variables.
Methods: Ninety patients referred to physical therapy due to LBP completed pain, disability, and fear-avoidance questionnaires, followed by a complete history and a physical examination based on mechanical diagnosis and therapy principles. Patients were subsequently classified as centralizers or noncentralizers. Univariate, followed by multivariate analysis was performed to identify history and physical examination variables that predicted the occurrence of the CP. Factors retained in the multivariate analysis were used to develop a clinical prediction rule (CPR).
Results: Twenty-eight patients (31%) were classified as centralizers immediately following assessment. Three predictors were retained in the multivariate analysis: (1) modified Oswestry Disability Index score lower than 33%; (2) intensity of the most distal symptom lower than 6/10; and (3) back pain equal to or greater than leg pain. The resultant CPR indicated the presence of all three variables increased the post-test likelihood of the CP to 57%.
Discussion: The findings of this study suggest the CP may be considerably more likely in less severe cases of LBP characterized by lower disability, lower intensity of distal symptoms, and a greater back-versus-leg pain intensity. Pending future validation, the CPR developed in this study may aide decision making regarding the initial management strategy of patients with LBP.
Keywords: Low back pain; centralization phenomenon; mechanical diagnosis and therapy.