Prognostic factors in complex regional pain syndrome 1: a systematic review.

OBJECTIVE The aim of this systematic review was to merge and summarize the current evidence about prognostic factors relevant to the course of complex regional pain syndrome 1. METHODS MEDLINE, Embase, PsychINFO, CENTRAL and screened reference lists of included studies were searched for studies of parameters associated with the prognosis of the condition. Studies investigating stroke-related complex regional pain syndrome were excluded. RESULTS Searches retrieved 2,577 references, of which 12 articles were included in the study. The preferred diagnostic criteria were the Veldman and the International Association for the Study of Pain criteria. The mean level of study quality was insufficient. A total of 28 prognostic factors was identified. Sensory disturbances and cold skin temperature appear to represent parameters associated with poor prognosis in complex regional pain syndrome 1. For many parameters the evidence is contradictory. CONCLUSION Evidence about prognostic factors for complex regional pain syndrome 1 is scarce, which prevents firm conclusions being drawn. Further high-quality aetiological and clinical research is needed.