Low back pain (LBP)-related disability involves patients with chronic outcome.
Objective: To identify the factors predictive of chronic evolution of acute LBP and to develop a predictive clinical index.
Patients and methods: Prospective investigation of 2487 employed patients referred for their first consultation with acute LBP (less than eight days). Chronic evolution defined by persistence of symptoms, unchanged or worse, at seven weeks. A predictive index was developed according to a logistic regression model.
Results: One hundred fifty-five patients (6.2%) were considered to have unchanged or worsened LBP at the time of final evaluation, which was carried out on average 42 +/- 15 days after the initial visit, and were thus regarded as having a chronic outcome. When comparing patients with chronic outcome and the others, there were 25 elementary characteristics for which the degree of significance of the bilateral test was less than 0.01. They were introduced into a logistic regression model. Five parameters appeared to be related to chronic outcome: characteristics of current episode (isolated acute low back pain, acute exacerbation of chronic low back pain, sciatica), two daily living activity items, duration of certificate to remain off work and taking part in a sport. They were used to develop an easily applied index providing identification, as of the initial consultation, of the risk of chronic evolution.
Conclusion: The early recognition of patients with LBP with high risk of chronic outcome can be achieved with an easily applied clinical index.