Predicting transition from acute to chronic low back pain with quantitative sensory tests - a prospective cohort study in the primary care setting

Background: It would be desirable to identify patients with acute low back pain (ALBP) who are at high risk for transition to chronic pain early in the course of their disease. This would enable early preventive or therapeutic interventions. Patients with chronic low back pain (CLBP) display signs of central hypersensitivity. This may contribute to the transition to CLBP. We tested the hypothesis that central hypersensitivity as assessed by quantitative sensory tests predicts transition to CLBP. Methods: We performed a prospective cohort study in 130 patients with ALBP recruited in a primary care setting to determine the ability of 14 tests using electrical, pressure and temperature stimulation to predict transition to CLBP after 6 months. We assessed the association of tests with transition to CLBP in multivariable analyses adjusted for socio-demographic, psychological and clinical characteristics, quantified the performance of tests using receiver operating characteristic (ROC) curves, and calculated likelihood ratios for different cut-off values for most promising tests. Results: None of the evaluated tests showed a statistically significant or clinically relevant ability to predict the transition to CLBP, with 95% CI of crude and adjusted associations of all tests including one as measure of no association. Corresponding estimates of areas under the ROC curves were below 0.5, and none of the 95% CI crossed the pre-specified boundary of clinical relevance set at 0.70. Conclusions: We found no evidence to support a clinically relevant ability of current quantitative sensory tests to predict the transition from acute to CLBP.