The nordic back pain subpopulation program: demographic and clinical predictors for outcome in patients receiving chiropractic treatment for persistent low back pain

Abstract

Objective: To identify demographic and clinic-related predictors for successful outcome in patients with persistent low-back pain who received chiropractic treatment.

Design: Prospective uncontrolled multicenter study with internal control groups.

Subjects: Each of 115 Norwegian chiropractors, out of 205 invited, were asked to recruit 10 consecutive patients who had low-back pain for at least 2 weeks at the time of consultation and a minimum of 30 days altogether within the preceding year. In all, 875 patients were included at baseline. The response rates at the fourth visit and at 3 and 12 months were 799, 598, and 512, respectively.

Methods: Baseline data were obtained through questionnaires administered to chiropractic patients and to their treating chiropractors; clinical information was obtained through questionnaires at the fourth visit from patients and chiropractors. Outcome was obtained from patients at the fourth visit. Mail surveys of patients were conducted after 3 and 12 months, and additional information was obtained from chiropractors at 12 months in relation to treatment history. POTENTIAL PREDICTORS: Demography and information on past and present history, clinical findings, and prognosis.

Outcome variable: Number of low-back pain"free patients (defined as those with a maximum pain score of 1/10 and a maximum Oswestry score of 15/100).

Data analysis: Positive predictive values and relative risks were calculated for each categorized predictor variable singly and in combination in relation to being low-back pain free at the 3 follow-up surveys.

Results: Treatment outcome at the fourth visit was best predicted by a model containing the following 5 variables: sex, social benefit, severity of pain, duration of continuous pain at first consultation, and additional neck pain (odds ratios between 2.2 and 4.3). A similar profile was found at 3 months, but 2 different variables (relating to disability) were the final variables in relation to the 12-month status. These final models were best at predicting absence of treatment success. Being low-back pain free at the fourth visit was a strong predictor for being low-back pain free both at 3 months and 12 months, with relative risks of 3.0 (2.2-4.8) and 3.1 (1.5-6.5), respectively.

Conclusion: In patients with persistent low-back pain, it is possible to exclude from treatment those who are unlikely to become low-back pain free after chiropractic care and to do this before they have been examined clinically. Early recovery is a strong predictor for outcome up to 1 year later.