Pain severity at emergency department discharge as a predictor for chronification of pain

Introduction: Inadequate pain management remains a problem in the emergency department (ED) and might increase the risk of chronic pain. Previous studies suggested that pain intensity is associated with pain chronification in specific patient groups. This study aims to study the association between pain intensity {[verbal] numeric rating scale ([V]NRS) ≥ 7} at discharge from the ED and pain chronification in the general population.

Objective: To assess whether a high pain score at discharge from the ED increases the risk of chronic pain development.

Methods: Adults who visited the ED with pain as their main complaint, and who were not hospitalized, were eligible for inclusion. Chronic pain was defined as pain with an (V)NRS score ≥1 90 days after the ED visit and with a similar location to the acute pain.

Results: We included 1906 patients, of whom 825 participants completed 90 days of follow-up. Approximately 34.1% left the ED with an (V)NRS score ≥7, and 67.8% reported an (V)NRS score of ≥1 90 at days. Of all patients leaving the ED with an (V)NRS score ≥7, 76.5% developed chronic pain vs 63.2% of patients with (V)NRS score <7 (P < 0.01). After correction, this difference was borderline statistically significant with an odds ratio of 1.45 (95% confidence interval: 0.99-2.13, P = 0.054). Various sensitivity analyses using a different (V)NRS at discharge and different definitions of chronic pain at 90 days showed a significant difference in the chronification of pain.

Conclusion: This study suggests that pain intensity at discharge from the ED, regardless of the localization or cause of pain, increased the risk of developing chronic pain. By distinguishing patients at risk and providing an effective treatment, chronic pain and the associated burden of disease might be preventable.