Predictors of Pain Severity 3 Months after Serious Injury

Objective. Injury is a common initiating event for persistent pain. The presentation of injured patients to hospital represents an opportunity to identify patients at high risk of persistent pain and triage them to early intervention. Although a range of physical, psychological, and social risk factors have been implicated in the transition from acute to persistent pain, these factors have not been tested concurrently in a prospective study. This study aimed to determine the degree to which pain severity at 3 months can be predicted at the time of injury and which independent factors predicted pain severity. Design. A large prospective cohort study was conducted recruiting patients from two trauma hospitals during their acute admission. Patients were assessed with a comprehensive battery of known and possible risk factors for persistent pain. Patients were assessed for pain severity on a visual analog scale over the past 24 hours at 3 months. Results. Two hundred ninety patients were recruited, and 242 were followed up at 3 months. Older age, female gender, past alcohol dependence, lower physical role function, pain severity, amount of morphine equivalents administered on the day of assessment, and pain control attitudes predicted pain severity at 3 months. The variance attributed to these factors was 22%. Conclusions. Injured patients with a number of these factors may warrant increased monitoring and early triage to specialist pain services.