Study design: Prospective inception cohort study.
Objectives: To compare the clinical course of fear-avoidance beliefs in acute and chronic low back pain (LBP) and investigate the contribution of fear-avoidance beliefs to predict pain and disability after 1 year.
Summary of background data: Fear-avoidance beliefs are involved in disability development. There is little knowledge on the development of fear-avoidance beliefs among different LBP subgroups.
Methods: Patients with acute (n = 123) and chronic (n = 50) LBP completed a comprehensive assessment, including the Fear-Avoidance Beliefs Questionnaire (FABQ), and were followed at 3, 6, 9, and 12 months.
Results: At baseline, patients with chronic LBP had significantly higher FABQ-scores for work (FABQ-Work) than patients with acute LBP (P < 0.001), and this difference remained unchanged over 1 year (P > 0.21). At baseline, there was no statistical significant difference in FABQ-scores for physical activity (FABQ-PA) between the two groups (P = 0.57). FABQ-PA scores decreased significantly over the first 4 weeks among patients with acute LBP during follow-up and remained unchanged thereafter, whereas in the chronic sample the FABQ-PA scores were unchanged throughout the first year (time effect, P < 0.001; and interaction effect, P < 0.001). In the acute sample, FABQ-Work predicted pain (P < 0.05) and disability at 12 months (P = 0.01). In the chronic sample, FABQ-PA predicted disability at 12 months (P = 0.03). The associations between the FABQ and pain/disability disappeared with distress included in the models.
Conclusion: Patients with chronic LBP had more fear-avoidance beliefs for work than patients with acute LBP. There were small changes in fear-avoidance beliefs during the year of follow-up, except for a rapid decrease during the first month in the FABQ-PA in the acute sample. Fear-avoidance beliefs predicted pain and disability at 12 months after adjusting for socio-demographic and pain variables. Distress was a stronger predictor than fear-avoidance beliefs.