Pain
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Facial expressions of pain have been identified in several animal species. The aim of this systematic review was to provide evidence on the measurement properties of grimace scales for pain assessment. The protocol was registered (SyRF#21-November-2019), and the study is reported according to the PRISMA guidelines. ⋯ Reliability and other forms of validity have been understudied. This systematic review identified gaps in knowledge on the measurement properties of grimace scales. Further studies should focus on improving psychometric testing, instrument refinement, and the use of grimace scales for pain assessment in nonhuman mammals.
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Many analgesics inadequately address the psychiatric comorbidities of chronic and persistent pain, but there is no standard preclinical model of pain-altered behavior to support the development of new therapies. To explore this conflicting and inconclusive literature, we conducted a focused systematic review and meta-analysis on the effect of complete Freund adjuvant-induced (CFA) rodent hind paw inflammation on multiple classical indicators of exploratory behavior, stress coping, and naturalistic behavior. Our primary objective was to define CFA's effect on assays including, but not limited to, the elevated plus maze and forced swim test. ⋯ Complete Freund adjuvant modestly but significantly decreased exploratory behavior, significantly increased passive stress coping in the tail suspension test but not the forced swim test, and significantly decreased preference for sucrose and naturally rewarding activity. Subgroup analyses revealed significant differences between species and animal sourcing. Based on the evidence provided here, we conclude future studies should focus on CFA's effect on natural rewards and naturalistic behaviors.
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In recent years, long-term prescribing and use of strong opioids for chronic noncancer pain (CNCP) has increased in high-income countries. Yet existing uncertainties, controversies, and differing recommendations make the rationale for prolonged opioid use in CNCP unclear. This systematic review and meta-analyses compared the efficacy, safety, and tolerability of strong opioids with placebo or nonopioid therapy in CNCP, with a special focus on chronic low back pain (CLBP). ⋯ Very low to low certainty findings suggest that 4 to 15 weeks (short or intermediate term) opioid therapy in CLBP (compared with placebo) may cause clinically relevant reductions in pain but also more gastrointestinal and nervous system adverse events, with likely no effect on disability. By contrast, long-term opioid therapy (≥6 months) in CNCP may not be superior to nonopioids in improving pain or disability or pain-related function but seems to be associated with more adverse events, opioid abuse or dependence, and possibly an increase in all-cause mortality. Our findings also underline the importance and need for well-designed trials assessing long-term efficacy and safety of opioids for CNCP and CLBP.
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Yoga is frequently used for back pain relief. However, the evidence was judged to be of only low to moderate certainty. To assess the efficacy and safety of yoga in patients with low back pain, a meta-analysis was performed. ⋯ Compared with passive control, yoga was associated with short-term improvements in pain intensity (15 RCTs; mean difference [MD] = -0.74 points on a numeric rating scale; 95% confidence interval [CI] = -1.04 to -0.44; standardized mean difference [SMD] = -0.37 95% CI = -0.52 to -0.22), pain-related disability (15 RCTs; MD = -2.28; 95% CI = -3.30 to -1.26; SMD = -0.38 95% CI = -0.55 to -0.21), mental health (7 RCTs; MD = 1.70; 95% CI = 0.20-3.20; SMD = 0.17 95% CI = 0.02-0.32), and physical functioning (9 RCTs; MD = 2.80; 95% CI = 1.00-4.70; SMD = 0.28 95% CI = 0.10-0.47). Except for mental health, all effects were sustained long-term. Compared with an active comparator, yoga was not associated with any significant differences in short-term or long-term outcomes.
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The number of placebo surgical trials on musculoskeletal conditions is increasing, but little is known about the quality of their design and methods. This review aimed to (1) assess the level of placebo fidelity (ie, degree to which the placebo control mimicked the index procedure) in placebo trials of musculoskeletal surgery, (2) describe the trials' methodological features using the adapted Applying Surgical Placebo in Randomised Evaluations (ASPIRE) checklist, and (3) describe each trial's characteristics. We searched 4 electronic databases from inception until February 18, 2021, for randomised trials of surgery that included a placebo control for any musculoskeletal condition. ⋯ According to the ASPIRE checklist, included trials had good reporting of the "rationale and ethics" (68% overall) and "design" sections (42%), but few provided enough information on the "conduct" (13%) and "interpretation and translation" (11%) of the placebo trials. Most trials sufficiently reported their rationale and ethics, but interpretation and translation are areas for improvement, including greater stakeholder involvement. Most trials used a high-fidelity placebo procedure suggesting an emphasis on blinding and controlling for nonspecific effects.