[Chronic low back pain: exercise therapy, multidisciplinary programs, NSAID's, back schools and behavioral therapy effective; traction not effective; results of systematic reviews].

OBJECTIVE: To inventory the current state of the art regarding the effectiveness of conservative treatment of chronic low back pain.
DESIGN: Systematic reviews.
METHOD: The relevant literature from the period January 1966-September 1999 was retrieved via Medline, Embase, PsychLit and the Cochrane Library and via reference lists in the articles found. The methodological quality of the studies was assessed using criteria for internal validity. On the basis of the number of examinations, their quality and the consistency of the findings, conclusions were subdivided into four levels of strength of scientific evidence.
RESULTS: There was strong evidence that exercise therapy and multidisciplinary treatment programmes were effective in chronic low back pain, and moderate evidence that non-steroidal anti-inflammatory drugs (NSAIDs), back schools and behavioural therapy were effective in chronic low back pain. There was also strong evidence that traction was not effective in chronic low back pain. Strong evidence for effectiveness of many other commonly used interventions was lacking.