Depression and Functional Outcomes in Patients Presenting to the Emergency Department With Low Back Pain

Abstract

Objectives: Low back pain (LBP) is a common reason for patients to present to emergency departments (EDs). Our objective was to describe the associations between depressive symptoms, pain severity, and functional impairment up to 3 months after initial ED presentation for LBP.

Methods: We performed a secondary analysis on an observational cohort of adult patients from a high-volume, urban ED. Initial depressive symptoms (Patient Health Questionnaire-9) and disability (Roland Morris Disability Questionnaire) were collected in person at the time of initial ED visit and by telephone at 1-week and 3-month follow-ups. Pain intensity (Numeric Rating Scale) was collected at 1-week and 3-month follow-ups. Our primary goal was to determine the associations between initial depressive symptoms and pain intensity and disability scores at 3 months. We also investigated the associations of initial and 3-month change in depressive symptoms with change in disability score from initial presentation to 3 months and change in pain score from 1 week to 3 months.

Results: Of the 674 patients initially enrolled, 362 patients had complete depressive symptom, pain, and disability data and were included in the final analysis. Those with higher levels of intake depressive symptoms had worse pain intensity (B = 0.14, 95% confidence interval [CI] = 0.08 to 0.21) and disability (0.46, 95% CI = 0.30 to 0.62) severity at 3 months, with less improvement in disability over the 3 months (B = 0.22, 95% CI = 0.05 to 0.40). Furthermore, those with worsening depressive symptoms over the 3-month study period experienced less improvement in pain intensity (B = 0.10, 95% CI = 0.05 to 0.17) and disability (B = 0.84, 95% CI = 0.66 to 1.02) over the same time frame. Except for a slight strengthening of the association between initial depressive symptom severity and 3-month pain score among patients with no prior LBP episodes, history of prior LBP episodes did not moderate these relationships.

Conclusions: Significant positive temporal associations exist between initial severity and 3-month progression of depressive symptoms and 3-month pain intensity and disability outcomes for ED patients with LBP. Future work is needed to investigate whether behavioral interventions initiated from the ED may mitigate the incidence and severity of LBP-related chronic pain and functional impairments.