A Systematic Review of Early Prognostic Factors for Persistent Pain Following Acute Orthopedic Trauma
Persistent or chronic pain is prevalent in many developed countries, with estimates ranging from 10% to higher than 50%, and is a major economic burden to individuals and societies. However, the variation in pain outcomes after acute orthopedic trauma and treatment confronts treating physicians with uncertainty in providing prognostic advice regarding long-term recovery. Although several previous reviews have addressed the determinants of chronic pain outcomes secondary to acute trauma, they have primarily focused on specific injury samples and, furthermore, lack consistency with respect to the important prognostic factors, which limits the generalizability of findings. This review, however, aimed specifically to identify the early prognostic factors associated with variation in persistent pain outcomes following acute orthopedic trauma presenting with a spectrum of pathologies.BACKGROUND: Acute orthopedic trauma contributes substantially to the global burden of disease.OBJECTIVES: The present systematic review aimed to summarize the current knowledge concerning prognostic factors for the presence of persistent pain, pain severity and pain-related disability following acute orthopedic trauma involving a spectrum of pathologies to working-age adults.METHODS: The Ovid MEDLINE and EMBASE databases were searched for level II prognostic studies published between January 1996 and October 2010. Studies that were longitudinal and reported results with multivariate analyses appropriate for prognostic studies were included. Studies that addressed two specific injury types that have been the subject of previous reviews, namely, injuries to the spinal column and amputations, were excluded.RESULTS: The searches yielded 992 studies; 10 studies met the inclusion criteria and were rated for methodological quality. Seventeen factors were considered in more than one cohort. There was strong evidence supporting the association of female sex, older age, high pain intensity, preinjury anxiety or depression, and fewer years of education with persistent pain outcomes. There was moderate evidence supporting the association between postinjury depression or anxiety with persistent pain, and that injury severity was not a risk factor for ongoing pain.CONCLUSION: Many individuals experience persistent pain following acute trauma. Due to the lack of studies, the use of different constructs to measure the same factor and the methodological limitations associated with many of the studies, the present review was only able to reliably identify a limited set of factors that predicted persistent pain. Recommendations for the conduct of future methodologically rigorous studies of persistent pain are provided.