A review and proposal for a core set of factors for prospective cohorts in low back pain: A consensus statement

Abstract

Introduction The Multinational Musculoskeletal Inception Cohort Study (MMICS) Statement is a consensus statement aimed at improving the quality of prospective investigations into the transition from early stages of low back pain (LBP) to persistent problems. The statement aims to help improve the quality of such studies by recommending an agreed minimal list of measures for inclusion in baseline data collection. The MMICS Statement is primarily aimed at researchers who want to investigate prognosis in LBP, and this will allow data from cohorts to be pooled and will facilitate comparisons between different health care systems. One approach to preventing acute new episodes of LBP (up to 3 weeks from onset) from developing into persistent disabling pain is to identify those individuals with LBP who are most likely to progress to chronic disability. Targeting interventions at those at highest risk could reduce the population burden of chronic LBP. A wide range of baseline parameters have been associated with poor outcome in inception cohort studies (1–6). Few existing studies have been of sufficient size and methodologic rigor to produce conclusive findings. Even in methodologically robust studies, baseline factors only account for a small proportion of the variance in outcome (7), typically around 30%. Systematic reviews of the literature could not pool data because studies used different measurements (1–3). Despite some information on physical, psychosocial, and work-related risk factors, it has not been possible to adequately estimate the comparative impact of individual psychosocial and societal factors on the transition from acute to persistent disabling LBP. How to address this problem was one focus of the VI International Forum for Primary Care Research in Low Back Pain held in April 2003. A steering group for the collaboration was appointed, and 8 national team leaders volunteered to recruit teams of national experts. Three additional team leaders were recruited by the steering group (Australia, France, and Germany). Independent experts were invited to advise on the quality of the MMICS process. The MMICS steering group, located in the UK, met regularly and included expert researchers in clinical and outcome factors in back pain (AB), work-related issues in back pain (AKB), psychosocial aspects of back pain (TP and RS), and general practice aspects of back pain (MU). The MMICS Statement set out to include 1) a minimal but comprehensive number of predictor factors based on current evidence and theory; 2) appropriate measurement instruments for agreed predictor factors based on their clinometric properties, availability, and practical characteristics; and 3) a minimum set of followup measures, including recommendations about measurement and timing.