Injury as a Risk Factor for Persistent Pain: Preliminary Results

There are no prospective studies on persistent pain after trauma. One retrospective study reports an 80% prevalence of pain one year after trauma, but pre-existing pain was not considered (1). We examined the relationship... [ view full abstract ]

There are no prospective studies on persistent pain after trauma. One retrospective study reports an 80% prevalence of pain one year after trauma, but pre-existing pain was not considered (1). We examined the relationship between pre-existing pain and persistent pain three months after traumatic injury and present preliminary results of an ongoing prospective study on patients > 18 years at a level-one trauma center. Patients were interviewed during hospitalization and three months after discharge via phone or internet-based survey. The presence of pain at three months was the primary outcome. We also examined widespread pain index (WPI) as the measure of widespread pain. Data are presented descriptively as mean ± SD, percent and odds ratios (95% CI), adjusted for gender and pre-existing pain.

One hundred and fifty-six patients, age 47±17 years, were enrolled; 45 (28%) were eligible for 3-month follow-up; 34 % reported pre-existing pain and 78% reported pain at 3 months. Patients with pre-existing pain had a 30% higher prevalence of persistent pain than patients without pre-existing pain (aOR 1.30; CI: 0.2-8.0). In the overall cohort (N=45), the WPI was higher at three months than at baseline (1.75 ± 1.5 vs. 1.09 ± 1.7 respectively). In patients with pre-existing pain (N=14) the WPI was also higher at three months than at baseline (2.5 ± 2.4 vs. 2.0 ± 1.93). The same was observed in patients without pre-existing pain (N=31) (1.6 ± 1.3 vs. 0.45 ± 0.72).

These preliminary results suggest that pre-existing pain is a risk factor for persistent pain. Widespread pain index increases at 3-months post injury. Injury is a risk factor for development of persistent pain, regardless of pre-existing pain.

References

1. Rivara, Arch Surg, 2008