The Nordic back pain subpopulation program: a 1-year prospective multicenter study of outcomes of persistent low-back pain in chiropractic patients.

ABSTRACT

OBJECTIVES: The aims of the study are to describe the low-back pain and disability status at baseline, the fourth visit, and at 3 and 12 months in Norwegian patients treated by chiropractors for persistent low back pain (LBP) and to describe movements between various subgroups over time. DESIGN: Prospective uncontrolled multicenter study. METHODS: Self-reported pain was measured with a 0-10 box scale and disability with the revised Oswestry LBP questionnaire. The main outcome measures were mean pain or disability values and numbers of LBP-free patients. LBP status was assessed through patient questionnaires at baseline, the fourth visit, and after 3 and 12 months. STUDY SUBJECTS AND SETTING: Of 205 invited chiropractors, 115 Norwegian chiropractors were each willing to recruit 10 consecutive patients who had LBP for at least 2 weeks at the time of consultation and a minimum of 30 days altogether within the preceding year. The numbers of participants were 875 (baseline), 799 (fourth visit), 598 (3 months), and 512 (12 months). RESULTS: Considerable improvement was noted between baseline and the fourth visit both for mean values and in numbers of LBP-free patients. There was virtually no further mean improvement up to the third month, whereas the number of LBP-free individuals doubled. At 12 months, no additional improvement was noted, and 80% reported that they had experienced recurrent problems. Less than 1% reported considerable worsening. Severity of symptoms at baseline determined the subsequent outcome, mild symptoms tending to worsen, and severe symptoms tending to improve. CONCLUSION: The outcome pattern is similar to that found in other clinical studies. Treatment outcome should be measured early with follow-up at 3 rather than at 12 months, because patients will improve or recover quickly but may experience recurring problems. Numbers "cured" appear to be a feasible outcome variable in this type of study population.