The journal of pain : official journal of the American Pain Society
-
Review Meta Analysis
The relation between pain-related fear and disability: a meta-analysis.
Within a biopsychosocial framework, psychological factors are thought to play an important role in the onset and progression of chronic pain. The cognitive-behavioral fear-avoidance model of chronic pain suggests that pain-related fear contributes to the development and maintenance of pain-related disability. However, investigations of the relation between pain-related fear and disability have demonstrated considerable between-study variation. The main goal of the current meta-analysis was to synthesize findings of studies investigating cross-sectional associations between pain-related fear and disability in order to estimate the magnitude of this relation. We also tested potential moderators, including type of measure used, demographic characteristics, and relevant pain characteristics. Searches in PubMed and PsycINFO yielded a total of 46 independent samples (N = 9,579) that reported correlations between pain-related fear and disability among persons experiencing acute or chronic pain. Effect size estimates were generated using a random-effects model and artifact distribution method. The positive relation between pain-related fear and disability was observed to be moderate to large in magnitude, and stable across demographic and pain characteristics. Although some variability was observed across pain-related fear measures, results were largely consistent with the fear-avoidance model of chronic pain. ⋯ Results of this meta-analysis indicate a robust, positive association between pain-related fear and disability, which can be classified as moderate to large in magnitude. Consistent with the fear-avoidance model of chronic pain, these findings suggest that pain-related fear may be an important target for treatments intended to reduce pain-related disability.
-
Review Meta Analysis
Primary somatosensory cortex function in complex regional pain syndrome: a systematic review and meta-analysis.
That complex regional pain syndrome (CRPS) is associated with functional reorganization in the primary somatosensory cortex (S1) is widely accepted and seldom questioned. Despite more than a decade of research, there has been no systematic review of the CRPS literature concerning the changes in S1 function, and therefore the extent of these changes is unclear. Here we conduct a systematic review and meta-analysis to quantify the spatial and temporal aspects of S1 function in CRPS. A comprehensive search strategy identified functional neuroimaging studies of S1 in CRPS. We adhered to a rigorous systematic review protocol when extracting data and appraising risk of bias. Outcomes were grouped into spatial representation; activation levels, including disinhibition; peak latency of activation; and glucose metabolism. Meta-analysis was conducted where possible. Fifteen studies were included, all investigating upper-extremity CRPS. In patients with CRPS, the S1 spatial representation of the affected hand is smaller than that of the unaffected hand and that of non-CRPS controls; however, this evidence comes from only a few studies. There is no difference in activation, disinhibition, or latency of peripherally evoked S1 responses in CRPS. The risk of bias was high across studies, mainly from unclear sampling methods and unblinded analysis of outcomes. ⋯ The evidence for a difference in function of the primary somatosensory cortex in CRPS compared with controls is clouded by high risk of bias and conflicting results, but reduced representation size seems consistent.