Background. Low back pain (LBP) is a major public health problem, often encountered in primary care. Guidelines recommend early identification of psychosocial factors that could prevent recovery from acute LBP.

Methods. To review the evidence on the prognostic value of psychosocial factors on transition from acute to chronic non-specific LBP in the adult general population. Systematic review is the design of the study. A systematic search was undertaken for prospective studies dealing with psychosocial risk factors for poor outcome of LBP in primary care, screening PuBmed, PsychInfo and Cochrane Library databases. The methodological quality of studies was assessed independently by two reviewers using standardized criteria before analysing their main results.

Results. Twenty-three papers fulfilled the inclusion criteria, covering 18 different cohorts. Sixteen psychosocial factors were analysed in three domains: social and socio-occupational, psychological and cognitive and behavioural. Depression, psychological distress, passive coping strategies and fear-avoidance beliefs were sometimes found to be independently linked with poor outcome, whereas most social and socio-occupational factors were not. The predictive ability of a patient’s self-perceived general health at baseline was difficult to interpret because of biomedical confounding factors. The initial patient's or care provider's perceived risk of persistence of LBP was the factor that was most consistently linked with actual outcome.

Conclusion. Few independent psychosocial risk factors have been demonstrated to exist. Randomized clinical trials aimed at modifying these factors have shown little impact on patient prognosis. Qualitative research might be valuable to explore further the field of LBP and to define new management strategies.