H3.5. Improving Acute Pain Measurement: The Acute Pain Trajectory “E”

Abstract

Acute pain is a time-limited process associated with the inflammatory phase of wound healing. Because time is an intrinsic feature of acute pain, measurement should characterize acute pain as a trajectory that begins with tissue trauma and resolves at a steady rate. Latent growth curve modeling of pain reports over six days in 502 postoperative and 513 emergency department patients reveals that: 1) Linear fits best characterize acute pain trajectories; and 2) The cardinal features of the acute pain trajectory are intercept (initial pain level) and slope (rate of pain resolution). The acute pain trajectory provides a more stable and precise estimate of acute pain for the individual patient than conventional point estimates and offers a stronger outcome measure in clinical trials. Randomized controlled trials of interventions using pain trajectories as outcomes can target rate of pain resolution as well as initial pain intensity. Pain trajectories also provide a good basis for comparing patient populations or cohorts (e.g., gender, age) and a basis for benchmarking institutions. This presentation will introduce the concept of pain trajectories, discuss options for estimating them statistically, and illustrate both individual cases and population mean estimates.