A SYSTEMATIC REVIEW OF PSYCHOLOGICAL FACTORS AS PREDICTORS OF CHRONICITY/DISABILITY IN PROSPECTIVE COHORTS OF LOW BACK PAIN

Abstract

Study design: A systematic review of prospective cohort studies in low back pain.

Objectives: To evaluate the evidence implicating psychological factors in the development of chronicity in low back pain.

Summary of background: The biopsychosocial model is gaining acceptance in low back pain, and has provided a basis for screening measurements, guidelines and interventions. However, to date, the unique contribution of psychological factors in the transition from an acute presentation to chronicity has not been rigorously assessed.

Methods: A systematic literature search was followed by the application of three sets of criteria to each study: methodological quality, quality of measurement of psychological factors, and quality of statistical analysis. Two reviewers blindly coded each study, followed by independent assessment by a statistician. Studies were divided into three environments: primary care, pain clinics and workplace-based studies.

Results: Twenty-five publications (18 cohorts) included psychological factors at baseline. Six of these met acceptability criteria for methodology, psychological measurement and statistical analysis. Increased risk of chronicity (persisting symptoms and/or disability) from depressive mood and, to a lesser extent, somatisation emerged as the main findings. Acceptable evidence generally was not found for other psychological factors, although weak support emerged for the role of catastrophising as a coping strategy.

Conclusions: Both depressive mood and somatisation are implicated in the transition to chronic low back pain. The development and testing of clinical interventions specifically targeting these factors is indicated. In view of the importance attributed to other psychological factors, there is a need to clarify their role in back-related disability through rigorous prospective studies.