Evidence from this systematic review and meta-analysis suggests that pain sensitization is present in people with knee OA and may be associated with knee OA symptom severity.

Background: In addition to fatigue, pain is the most frequent persistent symptom in cancer survivors. Clear guidelines for both the diagnosis and treatment of pain in cancer survivors are lacking. Classification of pain is important as it may facilitate more specific targeting of treatment. In this paper we present an overview of nociceptive, neuropathic and central sensitization pain following cancer treatment, as well as the rationale, criteria and process for stratifying pain classification. Material and methods: Recently, a clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain was developed, based on a large body of research evidence and international expert opinion. We, a team of 15 authors from 13 different centers, four countries and two continents have applied this classification algorithm to the cancer survivor population. Results: The classification of pain following cancer treatment entails two steps: (1) examining the presence of neuropathic pain; and (2) using an algorithm for differentiating predominant nociceptive and central sensitization pain.Step 1 builds on the established criteria for neuropathic pain diagnosis, whileStep 2 applies a recently developed clinical method for classifying any pain as either predominant central sensitization pain, neuropathic or nociceptive pain to the cancer survivor population. Conclusion: The classification criteria allow identifying central sensitization pain following cancer treatment. The recognition of central sensitization pain in practice is an important development in the integration of pain neuroscience into the clinic, and one that is relevant for people undergoing and following cancer treatment.

Sensitization of the nervous system can present as pain hypersensitivity that may contribute to clinical pain. In spinal pain, however, the relationship between sensory hypersensitivity and clinical pain remains unclear. This systematic review examined the relationship between pain sensitivity measured via quantitative sensory testing (QST) and self-reported pain or pain-related disability in people with spinal pain. Electronic databases and reference lists were searched. Correlation coefficients for the relationship between QST and pain intensity or disability were pooled using random effects models. Subgroup analyses and mixed effects meta-regression were used to assess whether the strength of the relationship was moderated by variables related to the QST method or pain condition. One hundred and forty-five effect sizes from 40 studies were included in the meta-analysis. Pooled estimates for the correlation between pain threshold and pain intensity were -0.15 (95% confidence interval [CI]: -0.18 to -0.11) and for disability -0.16 (95% CI: -0.22 to -0.10). Subgroup analyses and meta-regression did not provide evidence that these relationships were moderated by the QST testing site (primary pain/remote), pain condition (back/neck pain), pain type (acute/chronic), or type of pain induction stimulus (eg, mechanical/thermal). Fair correlations were found for the relationship between pain intensity and thermal temporal summation (0.26, 95% CI: 0.09 to 0.42) or pain tolerance (-0.30, 95% CI: -0.45 to -0.13), but only a few studies were available. Our study indicates either that pain threshold is a poor marker of central sensitization or that sensitization does not play a major role in patients' reporting of pain and disability. Future research prospects are discussed.

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Abstract-The use of quantitative sensory testing (QST) has become more widespread, with increasing focus on describing somatosensory profiles and pain mechanisms. However, the reliability of thermal QST has yet to be established. We systematically searched the literature using key medical databases. Independent reviewers evaluated reliability data using the Quality Appraisal for Reliability Studies checklist. Of the 21 studies we included in this review, we deemed 5 to have high methodological quality. Narrative analysis revealed that estimates of reliability varied considerably, but overall, the reliability of cold and warm detection thresholds ranged from poor to excellent, while heat and cold pain thresholds ranged from fair to excellent. The methodological quality of research investigating the reliability of thermal QST warrants improvement, particularly in terms of appropriate blinding. The results from this review showed considerable variability in the reliability of each thermal QST parameter.

In knee osteoarthritis (OA), pain sensitization has been linked to a more severe symptomatology, but the prognostic implications of pain sensitivity in people undergoing conservative treatment such as physiotherapy are not established. This study aimed to prospectively investigate the association between features of pain sensitization and clinical outcome (nonresponse) after guideline-based physiotherapy in people with knee OA. Participants (n = 156) with moderate/severe knee OA were recruited from secondary care. All participants completed self-administered questionnaires and underwent quantitative sensory testing at baseline, thereby establishing subjective and objective measures of pain sensitization. Participants (n = 134) were later classified after a physiotherapy intervention, using treatment responder criteria (responder/nonresponder). Quantitative sensory testing data were reduced to a core set of latent variables using principal component analysis. A hierarchical logistic regression model was constructed to investigate whether features related to pain sensitization predicted nonresponse after controlling for other known predictors of poor outcome in knee OA. Higher temporal summation (odds ratio 2.00, 95% confidence interval 1.23-3.27) and lower pressure pain thresholds (odds ratio 0.48, 95% confidence interval 0.29-0.81) emerged as robust predictors of nonresponse after physiotherapy, along with a higher comorbidity score. The model demonstrated high sensitivity (87.8%) but modest specificity (52.3%). The independent relationship between pain sensitization and nonresponse may indicate an underlying explanatory association between neuroplastic changes in nociceptive processing and the maintenance of ongoing pain and disability in knee OA pain. These preliminary results suggest that interventions targeting pain sensitization may warrant future investigation in this population.

BackgroundImaging is overused in the management of low back pain (LBP). Interventions designed to decrease non-indicated imaging have predominantly targeted practitioner education alone; however, these are typically ineffective. Barriers to reducing imaging have been identified for both patients and practitioners. Interventions aimed at addressing barriers in both these groups concurrently may be more effective. The Behaviour Change Wheel provides a structured framework for developing implementation interventions to facilitate behavioural change. The aim of this study was to develop an implementation intervention aiming to reduce non-indicated imaging for LBP, by targeting both general medical practitioner (GP) and patient barriers concurrently.MethodsThe Behaviour Change Wheel was used to identify the behaviours requiring change, and guide initial development of an implementation intervention. Preliminary testing of the intervention was performed with: 1) content review by experts in the field; and 2) qualitative analysis of semi-structured interviews with 10 GPs and 10 healthcare consumers, to determine barriers and facilitators to successful implementation of the intervention in clinical practice. Results informed further development of the implementation intervention.ResultsPatient pressure on the GP to order imaging, and the inability of the GP to manage a clinical consult for LBP without imaging, were determined to be the primary behaviours leading to referral for non-indicated imaging. The developed implementation intervention consisted of a purpose-developed clinical resource for GPs to use with patients during a LBP consult, and a GP training session. The implementation intervention was designed to provide GP and patient education, remind GPs of preferred behaviour, provide clinical decision support, and facilitate GP-patient communication. Preliminary testing found experts, GPs, and healthcare consumers were supportive of most aspects of the developed resource, and thought use would likely decrease non-indicated imaging for LBP. Suggestions for improvement of the implementation intervention were incorporated into a final version.ConclusionsThe developed implementation intervention, aiming to reduce non-indicated imaging for LBP, was informed by behaviour change theory and preliminary testing. Further testing is required to assess feasibility of use in clinical practice, and the effectiveness of the implementation intervention in reducing imaging for LBP, before large-scale implementation can be considered.Electronic supplementary materialThe online version of this article (10.1186/s12913-018-3526-7) contains supplementary material, which is available to authorized users.

This project will be a powerful resource to assist physiotherapists and clinicians across all areas of healthcare to diagnose pathology, track disease progression and evaluate treatment response. This reference dataset will also contribute to the development of robust patient-centred clinical trial outcome measures.