The prognostic value of catastrophizing for predicting the clinical evolution of low back pain patients: a study in routine clinical practice within the Spanish National Health Service

BACKGROUND CONTEXT: Experimental studies suggest that catastrophizing may worsen the prognosis of low back pain (LBP) and LBP-related disability and increase the risk of chronicity. PURPOSE: To assess the prognostic value of baseline catastrophizing for predicting the clinical evolution of LBP patients in routine clinical practice and the association between the evolution of pain and catastrophizing. STUDY DESIGN/SETTING: Prospective study in routine clinical practice of the Spanish National Health Service. PATIENT SAMPLE: One thousand four hundred twenty-two acute and chronic adult LBP patients treated in primary and hospital care. OUTCOME MEASURES: Pain, disability, and catastrophizing measured through validated instruments. METHODS: Patients were managed according to routine clinical practice. Outcome measures were assessed at baseline and 3 months later. Logistic regression models were developed to estimate the association between baseline catastrophizing score and the improvement of LBP and disability, adjusting for baseline LBP and leg pain (LP) severity, disability, duration of the pain episode, workers' compensation coverage, radiological findings, failed back surgery, and diagnostic procedures and treatments undertaken throughout the study. Another model was developed to estimate the association between the evolution of LBP and the change in catastrophizing, adjusting for the same possible confounders plus the evolution of LP and disability. Models were repeated excluding the treatments undergone after the baseline assessment. RESULTS: Regression models showed that the degree of baseline catastrophizing does not predict the evolution of LBP and disability. Conversely, as the degree of pain improvement increases, so does the odds ratio for improvement in catastrophizing, ranging from three (95% confidence interval [95% CI], 2.00-4.50; p<.001) for improvements in pain between 1.1 and 4 visual analog scale (VAS) points, to 7.3 (95% CI, 3.49-15.36; p<.001) for improvements in pain more than 6.1 VAS points. Similar results were obtained when treatments were excluded from the models. CONCLUSIONS: In routine practice, assessing the baseline score for catastrophizing does not help clinicians to predict the evolution of LBP and disability at 3 months. (C) 2012 Elsevier Inc. All rights reserved.