Acute Pain Resolution After an Emergency Department Visit: A 14-Day Trajectory Analysis

Ann Emerg Med. 2019 Aug;74(2):224-232. doi: 10.1016/j.annemergmed.2019.01.019. Epub 2019 Feb 21.


Study objective: The objective of the study is to evaluate the acute pain intensity evolution in emergency department (ED) discharged patients, using group-based trajectory modeling. This method identifies patient groups with similar profiles of change over time without assuming the existence of a particular pattern or number of groups.

Methods: This was a prospective cohort study of ED patients aged 18 years or older, with an acute pain condition (≤2 weeks), and discharged with an opioid prescription. Patients completed a 14-day diary assessing daily pain intensity level (numeric rating scale of 0 to 10) and pain medication use.

Results: Among the 372 included patients, 6 distinct post-ED pain intensity trajectories were identified. Two started with severe levels of pain; one remained with severe pain intensity (12.6% of the sample) and the other ended with a moderate pain intensity level (26.3%). Two other trajectories had severe initial pain; one decreased to mild pain (21.7%) and the other to no pain (13.8%). Another trajectory had moderate initial pain that decreased to a mild level (15.9%) and the last one started with mild pain intensity and had no pain at the end of the 14-day period (9.7%). The pain trajectory patterns were significantly associated with age, type of painful conditions, pain intensity at ED discharge, and opioid consumption.

Conclusion: Acute pain resolution after an ED visit seems to progress through 6 different trajectory patterns that are more informative than simple linear models and could be useful to adapt acute pain management in future research.

Trial registration: NCT02799004.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Pain / drug therapy*
  • Acute Pain / epidemiology
  • Acute Pain / etiology*
  • Adult
  • Analgesics, Opioid / therapeutic use
  • Emergency Service, Hospital / statistics & numerical data
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pain Management / statistics & numerical data*
  • Pain Measurement / statistics & numerical data
  • Pain Measurement / trends*
  • Patient Discharge / statistics & numerical data*
  • Prospective Studies
  • Severity of Illness Index
  • Treatment Outcome


  • Analgesics, Opioid

Associated data