Acute low back pain: predictive index of chronicity from a cohort of 2487 subjects

Low back pain (LBP)-related disability involves patients with chronic outco me, Objective. To identify the factors predictive of chronic evolution of a cute LBP and to develop a predictive clinical index. Patients and methods, Prospective investigation of 2487 employed patients referred for their firs t consultation with acute LBP (less than: eight days). Chronic evolution de fined by persistence of symptoms, unchanged or worse, at seven weeks. A pre dictive index was developed according to a logistic regression model. Resul ts. One hundred fifty-five patients (6.2%) were considered to have unchange d 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 o f significance of the bilateral test was less than 0.01. They were introduc ed 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 dai ly living activity items, duration of certificate to remain off work and fa king part in a sport. They were used to develop an easily applied index pro viding identification, as of the initial consultation, of the risk of chron ic evolution. Conclusion The early recognition of patients with LBP with hi gh risk of chronic outcome can be achieved with an easily applied clinical index. (C) 2000 Editions scientifiques et medicales Elsevier SAS.