A prospective study to compare serial changes in pain scores for patients with and without a history of frequent ED utilization.

Background: In the face of the opiate addiction epidemic, there is a paucity of research that evaluates limitations for our current pain rating methodologies for patient populations at risk for drug seeking behavior.

Objective: We hypothesized that VAS scores would be higher and show less serial improvement for patients with a history of frequent ED use.

Methods: This was a prospective, observational cohort study of a convenience sample of adult ED patients with chief complaint of pain. Initial VAS scores were recorded. Pain scores were subsequently updated 30-45 min after pain medication administration. ED frequenter defined as having >4 ED visits over a 1-year time period. Categorical data analyzed by chi-square; continuous data analyzed by t-tests. A multiple linear regression performed to control for confounding.

Results: 125 patients were enrolled; 51% ED frequenters. ED frequenters were similar to non-ED frequenters with respect to gender, mean age, Hispanic race, educational level, chief complaint type, and initial pain medication narcotic. ED frequenters more likely to have higher initial VAS score (9.17+/-1.25 vs. 8.51+/-1.68; p = 0.01) and higher second VAS scores (7.48+/-2.56 vs. 5.00+/-3.28; p <0.001) and significantly lower mean change in first to second VAS scores (1.69+/-2.17 vs. 3.51+/-3.25; p <0.001). Within our multiple linear regression model, only ED frequenter group (p < 0.001) and private insurance status (0.04) were associated with differences in mean reduction in pain scores.

Conclusion: We found that ED frequenters had significantly less improvement between first and second VAS measurements.