Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .
Acute pain after thoracic surgery predicts long-term post-thoracotomy pain.
OBJECTIVE Long-term pain is a common sequela of thoracotomy , occurring in approximately 50 % of patients 2 years after thoracic surgery . Despite this alarming statistic , little is known about the factors responsible for the transition of acute to chronic pain . The aim of the present study is to identify predictors of long-term post-thoracotomy pain . DESIGN Follow-up was for 1.5 years for patients who had participated in a prospect i ve , r and omized , controlled trial of preemptive , multimodal analgesia .  SETTING Subjects were recruited from a tertiary care center . PATIENTS Thirty patients who had undergone lateral thoracotomy  were followed up by telephone , administered a structured interview , and classified according to long-term pain status . MAIN OUTCOME MEASURES Present pain status was measured by a verbal rating scale ( VAS ) . Measures obtained within the first 48 h after surgery were compared between patients with and without pain 1.5 years later . These include VAS pain scores at rest and after movement , McGill Pain Question naire data , patient-controlled morphine consumption ( mg ) , and pain thresholds to pressure applied to a rib contralateral to the thoracotomy incision . RESULTS Fifty-two percent of patients reported long-term pain . Early postoperative pain was the only factor that significantly predicted long-term pain . Pain intensity 24 h after surgery , at rest , and after movement was significantly greater among patients who developed long-term pain compared with pain-free patients . A significant predictive relationship was also found at 24 and 48 h using the McGill Pain Question naire . Cumulative morphine was comparable for the two groups . Pain thresholds to pressure applied to a rib contralateral to the incision did not differ significantly between the groups . CONCLUSION Aggressive management of early postoperative pain may reduce the likelihood of long-term post-thoracotomy pain
Such interventions would have the potential to reduce the prevalence of chronic pain in the population .
Although certain risk factors can identify individuals who are most likely to develop chronic pain , few interventions to prevent chronic pain have been identified .
To facilitate the identification of preventive interventions , an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain .
We present general design considerations for prevention trials in population s that are at relatively high risk for developing chronic pain .