Un estudio longitudinal sobre la validez predictiva del modelo miedo-evitación del dolor de espalda baja

Recently, fear–avoidance models have been quite influential in understanding the transition from acute to chronic low back pain (LBP). Not only has pain-related fear been found to be associated with disability and increased pain severity, but also treatment focused at reducing pain-related fear has shown to successfully reduce disability levels. In spite of these developments, there is still a lack in well-designed prospective studies examining the role of pain-related fear in acute back pain. The aim of the current study was to prospectively test the assumption that pain-related fear in acute stages successfully predicts future disability. Subjects were primary care acute LBP patients consulting because of a new episode of LBP (≤3 weeks). They completed questionnaires on background variables, fear–avoidance model variables and LBP outcome (Graded Chronic Pain Scale, GCPS) at baseline, 3, 6, and 12 months follow-up and at the end of the study. Two-hundred and twenty-two acute LBP patients were included, of whom 174 provided full follow-up information (78.4%). A backward ordinal regression analysis showed previous LBP history and pain intensity to be the most important predictors of end of study GCPS. Of the fear–avoidance model variables, only negative affect added to this model. Our results do not really support the longitudinal validity of the fear–avoidance model, but they do feed the discussion on the role of pain-related fear in early stages of LBP.