A biopsychosocial primary care intervention (Back on Track) versus primary care as usual in a subgroup of people with chronic low back pain: protocol for a randomised, controlled trial

Multidisciplinary biopsychosocial interventions are effective at improving functional disability in people with chronic low back pain. However, these interventions are often expensive and have long waiting times before treatment starts. Therefore, implementing biopsychosocial interventions in primary care settings may be of interest. Because people with chronic low back pain show different biopsychosocial profiles, they might respond differently to specific interventions.This study will investigate the difference in (cost) effectiveness between a biopsychosocial primary care intervention, Back on Track, and primary care physiotherapy as usual in a subgroup of adults with chronic low back pain.Double-blind, multicentre (n = 8), randomised, controlled trial.Eighty-six adults with chronic low back pain, aged 18 to 65 years, experiencing low to moderate levels of disability and in whom the contributing role of psychosocial factors to this disability is restricted.The Back on Track intervention: four individual and eight group sessions, based on biopsychosocial approaches from multidisciplinary pain rehabilitation programs and provided by trained physiotherapists.Primary care physiotherapy as usual.The primary outcome is functional disability (Quebec Back Pain Disability Scale) at post treatment, and 3-month and 12-month follow-up. Secondary measures are: credibility and expectancy, anxiety and depression, catastrophising, pain intensity, kinesiophobia, self-efficacy, participant's global perceived effect, cost-effectiveness, and cost-utility estimated with cost diaries and quality-adjusted life years.Linear mixed models using an intention-to-treat principle. Incremental cost-effectiveness and cost-utility ratios will be calculated and plotted on a cost-effectiveness plane.This study will provide useful information on a biopsychosocial intervention for chronic low back pain in primary care settings. Australian Physiotherapy Association. Published b