322) Worsening Depressive Symptoms after an Emergency Department Visit for Low Back Pain are Associated with Persistent Pain and Disability

More than 2.5 million U.S. emergency department (ED) visits each year are for low back pain (LBP). Nearly half of these patients report persistent pain and functional disability 3 months later. While baseline depression has been shown to predict these poor outcomes, little is known about whether persistent pain and disability correlate with worsening depression. This is a secondary analysis of 362 patients seen at an urban ED with LBP who completed the Roland-Morris Disability Questionnaire (RMDQ), a 0-10 pain numeric rating scale (NRS), and Patient Health Questionnaire depression subscale (PHQ-9) at their ED visit and 3 months later. Linear regression analysis was used to determine the association between changes in depression severity from index ED visit to 3-month follow-up, and changes in RMDQ and pain scores over the same period. Models were adjusted for age, gender, race, ethnicity, education, and depression severity at baseline. At the index ED visit, median PHQ score was 0 (IQR 0,4) and median RMDQ score was 22 (IQR 17,24). At one week, median pain score was 6 (IQR 2,8). At 3 months, median change in PHQ from baseline was 0 (IQR -24,23), change in RMDQ was -8 (IQR -20,0), and change in pain score was -1 (IQR -3,0). After adjusting for potential confounders, worsening depression score between the ED visit and 3 month follow-up was associated with worsening function (B=0.85, 95% CI=0.68-1.03) and pain scores (B=0.11, 95%CI=0.05-0.17). The 3-month disability and pain intensity outcomes were more strongly correlated with change in depression than with baseline depression scores. Future work among ED patients with LBP should consider progressive depressive symptoms as a potentially modifiable risk factor for persistent pain and disability.