The centralization phenomenon. Its usefulness as a predictor or outcome in conservative treatment of chronic law back...

Two-hundred-forty-three patients with chronic low back pain were studied in a prospective comparative survey to determine whether the "centralization phenomenon" was associated with outcome after an interdisciplinary work-hardening program.

The hypothesis was that patients who demonstrated centralization during initial mechanical assessment would have better outcomes than noncentralizers.

Overall, subjects had decreased pain intensity ratings (mean 20%), increased lifting ability (6-8 kg), and a 59.2% return-to-work rate at a mean of 9.7 months follow-up.

Patients were classified as either centralizers or noncentralizers, based on results of their initial assessment. Changes in pain ratings, one-time maximal weights lifted, Oswestry scores, and return-to-work status were compared between groups.

The centralizers reported significant decreases in their maximum pain ratings (centralizers, 16%; noncentralizers, 6%) and had a higher return-to-work rate (centralizers, 68%; noncentralizers, 52%) than the noncentralizers.

Centralization can help identify sub-groups within the population with chronic low back pain and could be a useful goal setting and case management tool in the rehabilitation of low back pain.