Evaluating the relationship between pain and comfort in trauma patients at the Emergency Department, a prospective observational cohort study

Introduction
Traumatic injuries are among the most frequent presentations in the Emergency Department (ED), with acute pain being the predominant symptom. Traditionally unidimensional pain assessment tools, such as the Numeric Rating Scale (NRS), are deployed during pain management at the ED. This approach fails to capture the multidimensional nature of pain and comfort and may introduce negative verbal suggestion, potentially intensifying pain. In response, a revised pain management protocol was introduced, prioritizing patient-reported comfort over pain intensity alone. The primary objective of this study was to assess the association between NRS-measured pain intensity and patient-reported comfort among adults presenting with traumatic injuries to the ED. Secondary objectives included examining the relationship between pain intensity and analgesic requests and identifying a potential threshold for a Patient Acceptable Symptom State (PASS).
Materials and Methods
We conducted a prospective observational cohort study over an eight-week period in the ED of the Amsterdam UMC, location AMC. Adults presenting with traumatic injuries sustained within two days prior were eligible for inclusion. Key variables included patient-reported comfort, causes of discomfort, analgesic requests, and NRS pain scores. Baseline and, if applicable, post-treatment assessments were conducted at protocol-defined intervals. Statistical analyses comprised univariate logistic regression with NRS as the primary predictor and comfort and analgesic request as outcomes. Additionally, a 75th percentile distribution-based method and Receiver Operating Characteristics (ROC) curve analyses were employed to identify a PASS threshold.
Results
A total of 165 adult trauma patients were included (mean age = 49 years, SD = 21.6). Fractures were the most frequent diagnosis (n = 66, 40%). The majority of patients reported experiencing pain at baseline (73.9%, n = 122). Discomfort was reported by 29.7%, with 77.6% of these patients identifying pain as the primary cause (n = 49, n = 39 respectively).
Univariate logistic regression revealed a significant association between NRS scores and reported comfort: each one-point increase in NRS was associated with lower odds of comfort (OR: 0.68, 95% CI = 0.59-0.78). Higher NRS scores were also significantly associated with analgesic requests (OR: 1.67, 95% CI = 1.34-2.09). ROC curve analysis for predicting discomfort demonstrated acceptable discriminative ability (AUC: 0.79, 95% CI = 0.71-0.87), with the optimal Youden index identified at an NRS score of 4 (J = 0.44). The 75th percentile distribution-based approach identified an NRS score of 6 as a potential PASS threshold.
Conclusion
Among trauma patients presenting to the ED, increased NRS scores were significantly associated with reduced comfort and greater analgesic demand. This highlights that, although comfort is a subjective and multidimensional construct, pain plays a key role in both discomfort and the request for analgesics. A definitive PASS threshold could not be established due to the limited explanatory power of pain alone and the heterogeneity in reported comfort. These findings suggest that while pain is a key factor, a broader understanding of patients comfort may be needed to guide care in the ED.