495: Catastrophization, fear of movement, anxiety, and depression are associated with persistent, severe low back pain, and disability.

Background context: Psychological characteristics are important in the development and progression of low back pain (LBP); however, their role in persistent, severe LBP is unclear.

Purpose: To investigate the relationship between catastrophization, depression, fear of movement, and anxiety and persistent, severe LBP, and disability.

Study design/ setting: One-year prospective cohort study.

Patient sample: Participants were selected from the SpineData registry (Denmark), which enrolls individuals with LBP of 2 to 12 months duration without radiculopathy and without satisfactory response to primary intervention.

Outcome measures: Psychological characteristics, including catastrophization, depression, fear of movement, and anxiety, were examined at baseline using a validated screening questionnaire. Current, typical, and worst pain in the past 2 weeks were assessed by 11-point numeric rating scales and an average pain score was calculated. Disability was measured using the 23-item Roland-Morris Disability Questionnaire.

Methods: Participants completed baseline questionnaires on initial presentation to the Spine Center (Middelfart, Denmark), and follow-up questionnaires were sent and returned electronically. Statistical analysis involved multivariable Poisson regression to investigate the association between psychological factors and the number of episodes of severe pain or disability. This study received no direct funding.

Results: Of the 952 participants at baseline, 633 (63.4%) provided data 1 year later. Approximately half of the participants reported severe LBP (n=299, 47.2%, 95% confidence interval [CI] 43.3%-51.2%) or disability (n=315, 57.6%, 95% CI 53.3%-61.8%) at a minimum of one time point, and 14.9% (n=94, 95% CI 12.2%-17.9%) and 24.3% (n=133, 95% CI 20.8%-28.1%) experienced severe LBP or disability at two time points, respectively. Multivariable Poisson regression showed a relationship between catastrophization, depression, fear of movement, and anxiety and a greater number of time points with severe LBP and disability, after adjusting for age, gender, body mass index, and duration of symptoms. However, when all psychological factors were added to the regression model, only catastrophization and depression remained significantly associated.

Conclusions: This study showed that persistent, severe LBP, and disability is common in a secondary care population with LBP and is associated with a variety of psychological risk factors, in particular catastrophization and depression, highlighting the importance of considering these factors in the design and evaluation of outcomes studies for LBP.