Task-Specific Sensitivity in Physical Function Testing Predicts Outcome in Patients With Low Back Pain

Objective

To investigate the prognostic value of task-specific sensitivity in patients with low back pain by exploring whether task-specific sensitivity during physical function testing was associated with self-reported change in pain and disability.

Design

Prospective cohort study nested in a randomized controlled trial.

Methods

The study included 260 patients with low back pain, referred for evaluation in a secondary care setting. All patients completed questionnaires and underwent clinical examination by a physical therapist. Patients rated their pain intensity before and after completing a test battery measuring physical function and were classified into 4 categories—worse, unchanged, better, or no pain—depending on their pain response. At 3-month follow-up, outcomes were obtained by a postal questionnaire.

Results

Task-specific sensitivity significantly predicted pain, after adjusting for known prognostic factors. Patients in the no pain, better, and unchanged groups improved their pain score significantly more than patients in the worse pain group. Patients in the no pain group also improved their disability score significantly more compared to patients in the worse pain group, after adjusting for known prognostic factors.

Conclusion

Task-specific sensitivity predicted pain intensity after 3 months in patients with low back pain. The prognostic value appears limited with respect to disability.