Abstract
Introduction
Pain is a common and often debilitating sequelae of a significant burn injury. Clinicians and researchers need clinically valid, reliable pain measures to guide treatment decisions and to provide evidence for study protocol development. Pain rating scores that represent mild, moderate, and severe pain in the burn survivor population have not been established. The aim of this study was to determine the numerical pain intensity rating scores that best represent mild, moderate, and severe pain in adult burn survivors.
Methods
Average pain intensity visual analog scale (VAS; 0–10) and customized PROMIS pain interference short form was administered to adult burn survivors (age ≥18) treated at a regional burn center at hospital discharge and at 6, 12, and 24-months postburn. To identify the optimal VAS scores for mild, moderate, and severe pain we computed F values and Bayesian Information Criterion (BIC) statistics associated with multiple ANOVA comparisons for mean pain interference scores by various VAS pain intensity cut points. Six possible cut points (CP) were compared: CP 3,6; CP 3,7; CP 4,6; CP 4,7; CP 2,5; and CP 3,5. For example, CP 3,6 refers to pain categorized as mild (0–3), moderate (4–6), and severe (7–10). Optimal cutoffs were those with the highest ANOVA F statistics. Models with similar F statistics were compared using changes in BIC.
Results
178 participants (85% white, 65% male, mean age of 46 years) with pain intensity and interference scores at one or more timepoints comprised the study sample. The optimal classification for mild, moderate, and severe pain at baseline and 12-months was CP 2,5. Although CP 3,6 had the highest F value at 6-months, there was not strong evidence to support CP 3,6 over CP 2,5 (BIC difference: 2.9); similarly, CP 3,7 had the highest value at 24-months, but the BIC difference over CP 2,5 was minimal (2.2).
Conclusions
We recommend that visual analog pain intensity scores for adult burn survivors be categorized as mild (0–2), moderate (3–5), and severe (6–10). These findings advance our understanding regarding the meaning of pain intensity ratings following a burn injury and provide an objective definition for clinical management, quality improvement, and pain research.
