Chronic Pain Research Research Articles

A narrative review of data collection and analysis guidelines for comparative effectiveness research in chronic pain using patient-reported outcomes and electronic health records.

Chronic pain is a widespread and complex set of conditions that are often difficult and expensive to treat. Comparative effectiveness research (CER) is an evolving research method that is useful in determining which treatments are most effective for medical conditions such as chronic pain. An underutilized mechanism for conducting CER in pain medicine involves combining patient-reported outcomes (PROs) with electronic health records (EHRs). Patient-reported pain and mental and physical health outcomes are increasingly collected during clinic visits, and these data can be linked to EHR data that are relevant to the treatment of a patient’s pain, such as diagnoses, medications ordered, and medical comorbidities. When aggregated, this information forms a data repository that can be used for high-quality CER. This review provides a blueprint for conducting CER using PROs combined with EHRs. As an example, the University of Pittsburgh’s patient outcomes repository for treatment is described. This system includes PROs collected via the Collaborative Health Outcomes Information Registry software and cross-linked data from the University of Pittsburgh Medical Center EHR. The requirements, best practice guidelines, statistical considerations, and caveats for performing CER with this type of data repository are also discussed.

Urologic chronic pelvic pain syndrome: insights from the MAPP Research Network.

Urologic chronic pelvic pain syndrome (UCPPS), which encompasses interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, is characterized by chronic pain in the pelvic region or genitalia that is often accompanied by urinary frequency and urgency. Despite considerable research, no definite aetiological risk factors or effective treatments have been identified. The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network uses a novel integrated strategy to characterize UCPPS as a systemic disorder that potentially involves multiple aetiologies. The first phase, MAPP I, included >1,000 participants who completed an intensive baseline assessment followed by a 12-month observational follow-up period. MAPP I studies showed that UCPPS pain and urinary symptoms co-vary, with only moderate correlation, and should be evaluated separately and that symptom flares are common and can differ considerably in intensity, duration and influence on quality of life. Longitudinal clinical changes in UCPPS correlated with structural and functional brain changes, and many patients experienced global multisensory hypersensitivity. Additionally, UCPPS symptom profiles were distinguishable by biological correlates, such as immune factors. These findings indicate that patients with UCPPS have objective phenotypic abnormalities and distinct biological characteristics, providing a new foundation for the study and clinical management of UCPPS.

Conceptualizing pain-related stigma in adolescent chronic pain: a literature review and preliminary focus group findings.

Introduction:Chronic pain in adolescents is a significant medical condition, affecting the physical and psychological well-being of youth and their families. Pain-related stigma is a significant psychosocial factor in adolescents with chronic pain that has been understudied, despite its implications for negative health outcomes, poor quality of life, and increased healthcare utilization.Objectives:To examine pain-related stigma in the literature documenting pediatric and adult health-related stigma and present preliminary findings from a focus group of adolescents with chronic pain.Methods:In this narrative review, we explored pain-related stigma research and conceptualized the literature to address pain-related stigma among adolescents with chronic pain. Additionally, we conducted a focus group of four adolescent females with chronic pain and using content analyses, coded the data for preliminary themes.Results:We propose a pain-related stigma model and framework based on our review and the findings from our focus group. Findings suggest that medical providers, school personnel (ie, teachers and school nurses), peers and even family members enact pain-related stigma toward adolescents with chronic pain.Conclusions:Based on this narrative review, there is preliminary evidence of pain-related stigma among adolescents with chronic pain and future research is warranted to better understand the nature and extent of this stigma within this population.

Sensory sensitivity and symptom severity represent unique dimensions of chronic pain: a MAPP Research Network study.

Chronic overlapping pain conditions (COPCs) are characterized by aberrant central nervous system processing of pain. This "centralized pain" phenotype has been described using a large and diverse set of symptom domains, including the spatial distribution of pain, pain intensity, fatigue, mood imbalances, cognitive dysfunction, altered somatic sensations, and hypersensitivity to external stimuli. Here, we used 3 cohorts, including patients with urologic chronic pelvic pain syndrome, a mixed pain cohort with other COPCs, and healthy individuals (total n = 1039) from the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network to explore the factor structure of symptoms of centralized pain. Using exploratory and confirmatory factor analysis, we identified 2 general factors in all 3 cohorts, one characterized by a broad increased sensitivity to internal somatic sensations,environmental stimuli, and diffuse pain, termed Generalized Sensory Sensitivity, and one characterized by constitutional symptoms-Sleep, Pain, Affect, Cognition, Energy (SPACE). Longitudinal analyses in the urologic chronic pelvic pain syndrome cohort found the same 2-factor structure at month 6 and 1 year, suggesting that the 2-factor structure is reproducible over time. In secondary analyses, we found that Generalized Sensory Sensitivity particularly is associated with the presence of comorbid COPCs, whereas SPACE shows modest associations with measures of disability and urinary symptoms. These factors may represent an important and distinct continuum of symptoms that are indicative of the centralized pain phenotype at high levels. Future research of COPCs should accommodate the measurement of each factor.

The Intersections of Chronic Noncancer Pain: Culturally Diverse Perspectives on Disease Burden.

This study highlights the burden of chronic non-cancer-related pain from the perspectives of three culturally and linguistically diverse communities, using an intersectionality analysis. Specifically, we identify how multiple social identities intersect to account for the unequal distribution of the burden of chronic pain. Six focus groups of 41 culturally and linguistically diverse participants (Mandaean, Assyrian, and Vietnamese) living with chronic noncancer pain were conducted in South-West Sydney, Australia, between February and July 2015. Data were analyzed using inductive and intersectional methodology. The interaction between a patient with chronic pain from a culturally and linguistically diverse background and the health system is influenced by four identified social identities that interact to create relative positions of disadvantage for the patient within the health system and with health care providers. The social identities identified were ethnoculture, social class, migration status, and gender. Health care providers must consider how the intersectionality of social identities related to ethnoculture, social class, migration status, and gender can factor into the creation and maintenance of chronic pain disparities. A greater, more thoughtful incorporation of intersectionality in chronic pain research and clinical practice will ensure that pain management approaches are designed and applied in a way that reflects the social context of affected communities and individuals from those communities.

Physical Examination for Men and Women With Urologic Chronic Pelvic Pain Syndrome: A MAPP (Multidisciplinary Approach to the Study of Chronic Pelvic Pain) Network Study

To examine the feasibility of implementing a standardized, clinically relevant genitourinary examination for both men and women, and to identify physical examination findings characteristic of urologic chronic pelvic pain syndrome (UCPPS). This study analyzed 2 samples: men and women with UCPPS who participated in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network Epidemiology and Phenotyping (EP) Study, and age-matched controls who were either positive for chronic fatigue syndrome or healthy (pain-free). We compared physical examination findings in both positive and healthy controls with UCPPS cases: findings from both the EP examinations and from an extended genitourinary examination. EP and extended examinations were performed on 143 participants: 62 UCPPS cases (30 women, 32 men), 42 positive controls (15 women, 27 men), and 39 healthy controls (22 women, 17 men). EP examinations showed that pelvic floor tenderness was more prevalent in cases (55.0%) than in positive (14.6%) or healthy controls (10.5%). Extended examinations revealed specific areas of tenderness in the pelvic floor musculature. Cases were also more likely than healthy controls to report tenderness in multiple areas, including suprapubic, symphysis pubis, and posterior superior iliac spine, and on bimanual examination. No comparative findings were specific to biological sex, and no evidence of pudendal neuropathy was observed on extended examination of cases or controls. The extended genitourinary examination is an easily administered addition to the assessment of men and women during evaluation for UCPPS. Physical findings may help to better categorize patients with UCPPS into clinically relevant subgroups for optimal treatment.

The Regulatory Mechanisms and Therapeutic Potential of MicroRNAs: From Chronic Pain to Morphine Tolerance.

Chronic pain, including cancer-related pain, is a pain condition often caused by inflammation or dysfunctional nerves. Chronic pain treatment poses a significant health care challenge, where opioids especially morphine are widely used and patients often develop tolerance over time with aggravated pain. microRNA (miRNA) is known to play important roles in regulating gene expressions in the nervous system to affect neuronal network plasticity related to algogenesis and the developing of morphine tolerance. In this article, we reviewed studies conducted in rodent animal models investigating the mechanisms of miRNAs regulation in chronic pain with different phenotypes and morphine tolerance. In addition, the potential of targeting miRNAs for chronic pain and morphine tolerance treatment is also reviewed. Finally, we point out the directions of the future research in chronic pain and morphine tolerance.

Adverse Childhood Experiences and Symptoms of Urologic Chronic Pelvic Pain Syndrome: A Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network Study

Adverse Childhood Experiences (ACEs) such as sexual and physical violence, serious illness, and bereavement have been linked to number of chronic pain conditions in adulthood, and specifically to urologic chronic pelvic pain syndrome (UCPPS). We sought to characterize the prevalence of ACEs in UCPPS using a large well-characterized cohort in comparison with a group of healthy controls. We also sought to determine the association of ACE severity with psychological factors known to impact pain and to determine whether ACEs are associated with patterns of improvement or worsening of symptom over a year of naturalistic observation. For longitudinal analyses we used functional clusters identifying broad classes of (a) improved, (b) worsened, and (c) stable groups for genitourinary pain and urinary symptoms. We employed a mediation/path analysis framework to determine whether ACEs influenced 1 year outcomes directly, or indirectly through worse perceptions of physical well-being. ACE severity was elevated in UCPPS (n = 421) participants compared with healthy controls (n = 414; p < .001), and was most strongly associated with factors associated with complex chronic pain, including more diffuse pain, comorbid functional symptoms/syndromes, and worse perceived physical well-being (all p < .001). Finally, worse physical well-being mediated the relationship between ACE severity and less likelihood of painful symptom improvement (OR = .871, p = .007)) and a greater likelihood of painful symptom worsening (OR = 1.249, p = .003) at 1 year. These results confirm the association between ACEs and UCPPS symptoms, and suggest potential targets for therapeutic interventions in UCPPS. NCT01098279.

Review of chronic non-cancer pain research among Aboriginal people in Canada.

Aboriginal people in Canada are disproportionately affected by chronic illnesses, compared to non-Aboriginal Canadians. The purpose of this review was to determine whether differences exist between the two groups with respect to chronic non-cancer pain (CNCP) in order to better inform clinical practice and to identify research gaps. Four electronic databases were searched for the period of 1990-2015. Only English and French language original studies that examined CNCP prevalence, assessment tools and beliefs among Aboriginal people in Canada were considered. Data extracted included Aboriginal group, geographic location, study setting and pain definition (for prevalence studies only). A total of 11 studies matched the selection criteria: 10 reported estimates of chronic pain prevalence among Aboriginal people in Canada, 1 was about a culturally adapted pain assessment tool, and no study was found about CNCP beliefs within Aboriginal people. CNCP among Aboriginal people is still a largely unexplored research field. The limited evidence available so far does not allow us to conclude that CNCP affects a higher proportion of Aboriginal than non-Aboriginal people in Canada. However, arthritis, a specific condition associated with chronic pain, is more prevalent in Aboriginal than non-Aboriginal people. Additional research is needed on other CNCP types and conditions. Furthermore, pain assessment tools are not culturally adapted and clinicians should inquire more about the beliefs of Aboriginal patients to make them feel safer and to better target interventions.

Researching what matters to improve chronic pain care in Canada: A priority-setting partnership process to support patient-oriented research

ABSTRACT Background Chronic pain affects more than 6 million Canadians. Patients need to be involved in setting research priorities to ensure a focus on areas important to those who will be most impacted by the results. Aims The aim of this study was to leverage patient experiences to identify chronic pain research priorities in Canada. Method The process was informed by the James Lind Alliance. After gathering an exhaustive list of questions using surveys, town hall meetings, interviews, and social media consultations, we used a computerized Delphi with four successive iterations to select the final list of research priorities. The final Delphi round was conducted by a panel of ten patients living with chronic pain and ten clinicians from different disciplines. Results We received more than 5000 suggestions from 1500 people. The Delphi process led to the identification of 14 questions fitting under the following 4 themes: (1) improving knowledge and competencies in chronic pain; (2) improving patient-centered chronic pain care; (3) preventing chronic pain and reducing associated symptoms; and (4) improving access to and coordination of patient-centered chronic pain care. Challenges included the issue of chronic pain being ubiquitous to many diseases, leading to many initial suggestions focusing on these diseases. We also identified the need for further engagement efforts with marginalized groups in order to validate the priorities identified or identify different sets of priorities specific to these groups. Conclusion The priorities identified can guide patient-oriented chronic pain research to ultimately improve the care offered to people living with chronic pain.

Chronic musculoskeletal pain in European older adults: Cross-national and gender differences.

In an ageing Europe, chronic pain is a major public health problem, but robust epidemiological data are scarce. This study aimed to analyse the prevalence of and factors associated with chronic musculoskeletal pain by gender in older adults of 14 European countries. A cross-sectional study was performed from wave 5 of the Survey of Health, Ageing and Retirement in Europe (SHARE). The study included people ≥50 years residing in Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Luxembourg, the Netherlands, Slovenia, Spain, Sweden and Switzerland. Chronic pain was defined as being bothered by joint and/or back pain for the previous 6months. Multivariable Poisson regression models with robust variance were performed to analyse prevalence ratio by covariates, stratified by sex. A total of 61,157 participants were included. Overall prevalence of chronic musculoskeletal pain was 35.7% (28.8-31.7), ranging from 18.6% (17.1-20.1) for Switzerland to 45.6% (43.3-47.8) for France. Prevalence was higher in women than in men: 41.3% (40.2-42.4) versus 29.1% (28.0-30.3). Chronic musculoskeletal pain was lower in men aged >75 years (PR=0.82; 0.72-0.92) than the younger (50-59) group. Separated/divorced status presented opposite effects among men (PR=0.85; 0.76-0.96) and women (PR=1.12; 1.03-1.21) compared with married, and unemployment was a significant factor in men (PR=1.21; 95% CI 1.02-1.43) compared with employed. Musculoskeletal pain in older European adults is very frequent, especially in women, with large differences depending on the country of residence. Health policy makers should prioritize strategies aimed at improving the prevention and management of chronic musculoskeletal pain in Europe. This study provides epidemiological data of chronic musculoskeletal pain in older adults. Reported differences contribute to highlight the relevance of considering a gender perspective in chronic musculoskeletal pain research. Cross-national comparison also offers a map of differences that improves the knowledge of this chronic condition in Europe.

Sacral neuromodulation for pelvic pain and pelvic organ dysfunction: A case series.

The use of neuromodulation is growing and it is an established therapy for conditions such as bladder dysfunction. It is an increasingly used therapy for the management of chronic perineal pain but little research is currently available looking at its efficacy. We present a series of 52 patients who underwent placement of a neuromodulator, the majority of whom suffered from perineal pain, with most placements via the sacral hiatus. Patients were asked to complete a survey recalling their symptoms prior to implantation and describing their symptoms and experience after. The majority had two leads placed via the sacral hiatus. Fifty-two patients had implantation of a permanent neuromodulator and 44 completed at least part of the survey. Forty-eight had leads placed via the sacral hiatus, 29 of whom had these leads only. Forty patients had perineal pain as an indicator and 32 reported that their pain improved; this difference was statistically significant (95% CI: 2.60-4.27, P<0.001). Bladder, bowel and sexual dysfunction were reported by about half the cohort with smaller numbers of improvement for each. Thirty-five patients reported improved quality of life and 32 said they would have the procedure done again. Ten patients had the device removed. We present the largest published case series looking at the use of sacral neuromodulation as a treatment option for pelvic pain and the overall results of our audit are promising for the ongoing use and further development of this modality as a management option.

Chronic Pain and Neuropathy Following Adjuvant Chemotherapy.

To determine symptoms and characteristics of chronic sensory neuropathy in patients treated with oxaliplatin and docetaxel, including patterns of somatosensory abnormalities, pain descriptors, and psychological functioning. A retrospective cross-sectional study. A chronic pain research center. Thirty-eight patients with chronic peripheral pain and/or dysesthesia following chemotherapy. Sensory profiles, psychological functioning, and quality of life were assessed using standardized questionnaires. In addition, standardized quantitative sensory testing and nerve conduction studies were carried out. The sensory profiles and clinical symptoms were very similar in the two groups. Pricking, numbness, and burning were common descriptors in both groups, and the predominant finding was sensory loss to A beta-mediated sensory modalities with decreased mechanical and vibration detection thresholds. A high frequency of abnormalities in thermal sensory limen and the presence of paradoxical heat sensation seem to be sensitive markers of small fiber loss. Both groups had mainly sensory, axonal large fiber or mixed fiber polyneuropathy, which tended to be most severe in the oxaliplatin group. Both oxaliplatin-induced and docetaxel-induced polyneuropathies represent a significant problem that affects the daily life of the patients. Our results, defining the somatosensory phenotype, can improve the understanding of the pathophysiological mechanisms useful for future studies in the tailored treatment of prevention of chemotherapy-induced peripheral neuropathy and pain.

Provoked vestibulodynia: current perspectives.

Provoked vestibulodynia (PVD) refers to vulvar pain of at least 3 months duration, localized to the vestibule, provoked by touch and sexual activity and occurring in the absence of a clear identifiable cause. The clinical spectrum ranges from mild with distressing discomfort through to severe and disabling pain. Current understanding is that PVD is one of many chronic pain conditions characterized by sensitization of peripheral and central nociceptive pathways, with pain arising due to dysfunctional neuronal activity in the absence of painful stimuli. Pathophysiology is not well understood but is likely a complex interplay of environmental, genetic, psychological and immune factors. Care is multidisciplinary and follows general principles of chronic pain management with the addition of specific therapy tailored to address pelvic floor overactivity, and sexual and relationship difficulties. More recently, the therapeutic use of placebo is gaining traction in chronic pain research and is a very promising adjunctive therapy. The majority of women with PVD are managed outside of tertiary clinic settings, and care depends on availability and affordability of specialized services; however, much can be done by the primary health provider. PVD is common, and highly treatable, especially with early intervention, but unfortunately, many clinicians are unaware of this condition, and the biggest hurdle for women accessing treatment is obtaining a diagnosis. With treatment, most women can expect significant improvement, often with fairly simple interventions, although some women will benefit from referral to specialized centers. The aims of this article are twofold: firstly, to summarize current literature concerning PVD pathophysiology and management; secondly, to provide a framework for clinicians unfamiliar with vulvar medicine to understand and manage PVD.

Topical Review: Pain in Survivors of Pediatric Cancer: Applying a Prevention Framework

To apply a biopsychosocial framework to understand factors influencing pain in survivors of pediatric cancer to inform pain prevention efforts and highlight the need for interdisciplinary care. This topical review draws from both pediatric cancer survivorship research and chronic noncancer pain research to illustrate how components of a preventative model can be applied to pain in survivorship. Pain is a common experience among long-term survivors of pediatric cancer. The pain experience in survivorship can be conceptualized in terms of biological disease and treatment factors, cognitive and affective factors, and social and contextual factors. We review literature pertinent to each of these biopsychosocial factors and tailor an existing public health prevention framework for pain in survivors of pediatric cancer. Classifying survivors of pediatric cancer into pain risk categories based on their daily experiences of pain, pain-related functional impairment, and distress could help guide the implementation of pain-related prevention and intervention strategies in this population. Future research is needed to establish the efficacy of screening measures to identify patients in need of psychosocial pain and pain-related fear management services, and interdisciplinary pediatric chronic pain management programs in survivors of pediatric cancer.

Brain signature and functional impact of centralized pain: a multidisciplinary approach to the study of chronic pelvic pain (MAPP) network study.

Chronic pain is often measured with a severity score that overlooks its spatial distribution across the body. This widespread pain is believed to be a marker of centralization, a central nervous system process that decouples pain perception from nociceptive input. Here, we investigated whether centralization is manifested at the level of the brain using data from 1079 participants in the Multidisciplinary Approach to the Study of Chronic Pelvic Pain Research Network (MAPP) study. Participants with a clinical diagnosis of urological chronic pelvic pain syndrome (UCPPS) were compared to pain-free controls and patients with fibromyalgia, the prototypical centralized pain disorder. Participants completed questionnaires capturing pain severity, function, and a body map of pain. A subset (UCPPS N = 110; fibromyalgia N = 23; healthy control N = 49) underwent functional and structural magnetic resonance imaging. Patients with UCPPS reported pain ranging from localized (pelvic) to widespread (throughout the body). Patients with widespread UCPPS displayed increased brain gray matter volume and functional connectivity involving sensorimotor and insular cortices (P < 0.05 corrected). These changes translated across disease diagnoses as identical outcomes were present in patients with fibromyalgia but not pain-free controls. Widespread pain was also associated with reduced physical and mental function independent of pain severity. Brain pathology in patients with centralized pain is related to pain distribution throughout the body. These patients may benefit from interventions targeting the central nervous system.

Anti-vascular endothelial growth factor treatment decreases bladder pain in cyclophosphamide cystitis: a Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network animal model study.

To investigate whether treatment with anti-vascular endothelial growth factor (VEGF)-neutralizing antibodies can reduce pain and voiding dysfunction in the cyclophosphamide (CYP) cystitis model of bladder pain in mice. Adult female mice received anti-VEGF-neutralizing antibodies (10mg/kg i.p. B20-4.1.1 VEGF mAb) or saline (control) pre-treatment, followed by CYP (150mg/kg i.p.) to induce acute cystitis. Pelvic nociceptive responses were assessed by applying von Frey filaments to the pelvic area. Spontaneous micturition was assessed using the void spot assay. Systemic anti-VEGF-neutralizing antibody treatment significantly reduced the pelvic nociceptive response to CYP cystitis compared with control (saline). In the anti-VEGF pre-treatment group, there was a significant increase in pelvic hypersensitivity, measured by the area under the curve (AUC) using von Frey filaments at 5h post-CYP administration (P = 0.004); however, by 48h and 96h post-CYP administration, pelvic hypersensitivity had reduced by 54% and 47%, respectively, compared with the 5h post-CYP administration time point, and were no longer significantly different from baseline (P = 0.22 and 0.17, respectively). There was no difference in urinary frequency and mean voided volume between the two pre-treatment groups. Systemic blockade of VEGF signalling with anti-VEGF-neutralizing antibodies was effective in reducing pelvic/bladder pain in the CYP cystitis model of bladder pain. Our data support the further investigation of the use of anti-VEGF antibodies to manage bladder pain or visceral pain.

Towards a science and practice of resilience in the face of pain.

The resilience approach put forward in this review spotlights sustainability of positive outcomes (e.g. engagement in meaningful activities) in the presence of pain as an outcome to pursue beyond recovery of negative outcomes. We illuminate the evidence-base and practical application of promising resilience mechanisms (positive emotions, psychological flexibility, needs satisfaction). For this article, a commentary is available at the Wiley Online Library.

Resting-state functional connectivity predicts longitudinal pain symptom change in urologic chronic pelvic pain syndrome: a MAPP network study.

Chronic pain symptoms often change over time, even in individuals who have had symptoms for years. Studying biological factors that predict trends in symptom change in chronic pain may uncover novel pathophysiological mechanisms and potential therapeutic targets. In this study, we investigated whether brain functional connectivity measures obtained from resting-state functional magnetic resonance imaging at baseline can predict longitudinal symptom change (3, 6, and 12 months after scan) in urologic chronic pelvic pain syndrome. We studied 52 individuals with urologic chronic pelvic pain syndrome (34 women, 18 men) who had baseline neuroimaging followed by symptom tracking every 2 weeks for 1 year as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network study. We found that brain functional connectivity can make a significant prediction of short-term (3 month) pain reduction with 73.1% accuracy (69.2% sensitivity and 75.0% precision). In addition, we found that the brain regions with greatest contribution to the classification were preferentially aligned with the left frontoparietal network. Resting-state functional magnetic resonance imaging measures seemed to be less informative about 6- or 12-month symptom change. Our study provides the first evidence that future trends in symptom change in patients in a state of chronic pain may be linked to functional connectivity within specific brain networks.

Concurrent validity of pain scales in individuals with myofascial pain and fibromyalgia

ObjectiveClinicians and researchers often use the numeric pain rating scale (NPRS) and visual analog scale (VAS) to measure and track pain in individuals with myofascial pain syndrome (MPS) and fibromyalgia (FM). The VAS is often used as a reference standard in chronic pain research. To date, no studies have specifically measured the concurrent validity of the NPRS and VAS in these individuals. The purpose of this investigation was to determine the concurrent validity of the NPRS when compared to the reference standard VAS in patients with MPS and FM. MethodsThis investigation explored the concurrent validity of the NPRS and VAS in sixty participants with MPS (N = 30) and FM (N = 30). All participants underwent one day of testing using the American College of Rheumatology criteria for classifying FM. For each tender point (18-total), participants graded tenderness using the NPRS and VAS. ResultsAn excellent relationship was found between the NPRS and VAS for the MPS group (rho≥0.81, 95% CI 0.79-0.85, p < 0.001) and the FM group (rho ≥0.96, 95% CI 0.92-0.97, p < 0.001). ConclusionThe results of this study suggest that the NPRS has good concurrent validity with the referenced standard VAS among individuals with MPS and FM.