Researchers Seek to Better Understand Transition from Acute to Chronic Pain

By Elesa Swirgsdin
Monday, November 29, 2021

The NIH Acute to Chronic Pain Signatures program will identify chronic pain biomarkers, helping physicians predict which patients will develop chronic pain.

Chronic pain affects millions of people in the United States, leading to a decreased quality of life and mental health problems for many of those affected. The high percentage of people who transition from acute pain to chronic pain following surgery is considered a major factor in the ongoing opioid epidemic. Experts have long been perplexed by what, exactly, leads to the development of chronic pain in some individuals — but not others — after acute pain events.

Researchers are striving to answer this question in a new study that will identify biomarkers to help understand what causes chronic pain and better predict which patients will experience it after surgery.

“There is much about the etiology and pathogenesis of chronic pain that we do not understand,” says Joshua J. Jacobs, MD, Professor and Chair of the Department of Orthopaedic Surgery at Rush University Medical Center. “Delineation of the pathways leading to the transition from acute to chronic pain following surgery can lead to the identification of therapeutic targets to prevent or mitigate this outcome.”

Understanding What Drives Chronic Pain

Experts believe that many different factors contribute to the transition from acute to chronic pain, including psychosocial, neurophysiologic, immunologic and metabolic factors. However, a lack of focused research has stymied the development of evidence-based best practices that could be used in pain care.

The Acute to Chronic Pain Signatures (A2CPS) program, funded by the National Institutes of Health Common Fund, will seek to predict patients’ susceptibility or resilience to chronic pain. The study will track 3,600 people, 1,800 undergoing total knee arthroplasty and 1,800 having a thoracotomy. Using brain imaging, quantitative sensory testing, psychological assessment and multiomics analysis, researchers will develop individual biomarkers, or combinations of biomarkers (signatures), to predict which patients will develop chronic postoperative pain.

Researchers will collect data on patients for a period of six months following surgery, with the goal of using this information to understand the mechanisms behind the development of chronic pain.

“The identification of individuals at risk for the transition from acute to chronic pain before surgical intervention will enhance the ability of orthopedic surgeons to provide the patient a more accurate prognosis of surgical outcomes and refine indications for surgical intervention,” says Dr. Jacobs, one of the physicians involved with the study. “[It will also help] identify individuals who may have modifiable risk factors for the transition from acute to chronic pain, which can be addressed prior to surgery in order to improve the likelihood of a pain-free outcome.”

The A2CPS program is part of the Helping to End Addiction Long-term Initiative, which funds hundreds of research projects throughout the country to establish scientific solutions to the opioid crisis.

For more information on the A2CPS program, visit