A Systematic Review of the Association Between Perceived Injustice and Pain-Related Outcomes in Individuals with Musculoskeletal Pain.

OBJECTIVE: A growing body of literature shows that justice-related appraisals are significant determinants of pain-related outcomes and prolonged trajectories of recovery. We conducted a systematic review of the literature assessing the relationship between perceived injustice and pain-related outcomes in individuals with musculoskeletal pain. DESIGN AND PARTICIPANTS: A search of published studies in English in PubMed, PsychInfo, Embase, and Cochrane Database of Systematic Reviews from database inception through May 2019 was performed. Search terms included "perceived injustice," "injustice appraisals," "perceptions of injustice," and "pain" or "injury." RESULTS: Thirty-one studies met inclusion criteria. Data for a total of 5,969 patients with musculoskeletal pain were extracted. Twenty-three studies (71.9%) reported on individuals with persistent pain lasting over three months, and 17 studies (53.1%) reported on individuals with injury-related musculoskeletal pain. Significant associations were found between perceived injustice and pain intensity, disability and physical function, symptoms of depression and anxiety, post-traumatic stress disorder, quality of life and well-being, and quality of life and social functioning. CONCLUSIONS: This systematic review summarizes the current evidence for the association between perceived injustice and pain-related outcomes. There is strong evidence that perceived injustice is associated with pain intensity, disability-related variables, and mental health outcomes. Implications and directions for future research are discussed.

Recovery expectations can be assessed with single-item measures: findings of a systematic review and meta-analysis on the role of recovery expectations on return-to-work outcomes after musculoskeletal pain conditions.

ABSTRACT: The objective of this systematic review is to quantify the association between recovery expectations and return-to-work outcomes in adults with musculoskeletal pain conditions. In addition, this review has the second objective to compare the predictive utility of single-item and multi-item recovery expectation scales on return-to-work outcomes. Relevant articles were selected from Embase, PsycINFO, PubMed, Cochrane, and manual searches. Studies that assessed recovery expectations as predictors of return-to-work outcomes in adults with musculoskeletal pain conditions were eligible. Data were extracted on study characteristics, recovery expectations, return-to-work outcomes, and the quantitative association between recovery expectations and return-to-work outcomes. Risk of bias was assessed using the Effective Public Health Practice Project. Odds ratios were pooled to examine the effects of recovery expectations on return-to-work outcomes. Chi-square analyses compared the predictive utility of single-item and multi-item recovery expectation scales on return-to-work outcomes. Thirty studies on a total of 28,741 individuals with musculoskeletal pain conditions were included in this review. The odds of being work disabled at follow-up were twice as high in individuals with low recovery expectations (OR = 2.06 [95% CI 1.20-2.92] P < 0.001). Analyses also revealed no significant differences in the predictive value of validated and nonvalidated single-item measures of recovery expectations on work disability (χ 2 = 1.68, P = 0.19). There is strong evidence that recovery expectations are associated with return-to-work outcomes. The results suggest that single-item measures of recovery expectations can validly be used to predict return-to-work outcomes in individuals with musculoskeletal pain conditions.

Long-term male-specific chronic pain via telomere- and p53­mediated spinal cord cellular senescence.

Mice with experimental nerve damage can display long­lasting neuropathic pain behavior. We show here that 4 months and later after nerve injury, male but not female mice displayed telomere length (TL) reduction and p53­mediated cellular senescence in the spinal cord, resulting in maintenance of pain and associated with decreased lifespan. Nerve injury increased the number of p53­positive spinal cord neurons, astrocytes, and microglia, but only in microglia was the increase male­specific, matching a robust sex specificity of TL reduction in this cell type, which has been previously implicated in male­specific pain processing. Pain hypersensitivity was reversed by repeated intrathecal administration of a p53­specific senolytic peptide, only in male mice and only many months after injury. Analysis of UK Biobank data revealed sex-specific relevance of this pathway in humans, featuring male­specific genetic association of the human p53 locus (TP53) with chronic pain and a male-specific effect of chronic pain on mortality. Our findings demonstrate the existence of a biological mechanism maintaining pain behavior, at least in males, occurring much later than the time span of virtually all extant preclinical studies.