Patients' perspective on the chronic pain classification in the 11th revision of the International Classification of Diseases (ICD-11): results from an international web-based survey.

ABSTRACT: The 11th revision of the International Classification of Diseases and Related Health Problems (ICD-11) aims at improving the lives of persons with the lived experience of chronic pain by providing clearly defined and clinically useful diagnoses that can reduce stigma, facilitate communication, and improve access to pain management, among others. The aim of this study was to assess the perspective of people with chronic pain on these diagnoses. An international web-based survey was distributed among persons with the lived experience of chronic pain. After having seen an information video, participants rated the diagnoses on 8 endorsement scales (eg, diagnostic fit, stigma) that ranged from -5 to +5 with 0 representing the neutral point of no expected change. Overall ratings and differences between participants with chronic primary pain (CPP) and chronic secondary pain (CSP) were analyzed. N = 690 participants were included in the data analysis. The ratings on all endorsement scales were significantly higher than the neutral point of 0. The highest ratings were obtained for "openness" (2.95 ± 1.93) and "overall opinion" (1.87 ± 1.98). Participants with CPP and CSP did not differ in their ratings; however, those with CSP indicated an improved diagnostic fit of the new diagnoses, whereas participants with CPP rated the diagnostic fit of the new diagnoses similar to the fit of their current diagnoses. These results show that persons with the lived experience of chronic pain accept and endorse the new diagnoses. This endorsement is an important indicator of the diagnoses' clinical utility and can contribute to implementation and advocacy.

Pediatric chronic pain grading: a revised classification of the severity of pediatric chronic pain.

ABSTRACT: In this study, we describe the development and validation of a revised Pediatric Chronic Pain Grading (P-CPG) for children aged 8 to 17 years that adds emotional impairment to previously used measures of pain intensity and functional impairment. Such a measure enables the assessment of chronic pain severity in different epidemiological and clinical populations, the stratification of treatment according to pain severity, and the monitoring of treatment outcome. The P-CPG was developed using a representative sample of school children with chronic pain (n = 454; M age = 12.95, SD = 2.22). Construct validity and sensitivity to change were examined within a sample of N = 2448 children and adolescents (M age = 12.71, SD = 2.47) comprising 3 subsamples (school n = 1562, primary care n = 129, and tertiary care n = 757) affected by chronic pain to varying extents. Results showed that P-CPG grades differed significantly among the 3 subsamples, with school children being least affected by chronic pain and tertiary care patients being most affected. As P-CPG grade increased, so did pain intensity, functional impairment, pain-related school absence, and emotional impairment. Convergent validity was demonstrated by significant positive correlations between the P-CPG and global ratings of pain severity as well as objective claims data; the latter reflects greater health care costs with increasing P-CPG scores. Sensitivity to change was supported by a significant reduction in baseline P-CPG grades 3 and 6 months after intensive interdisciplinary pain treatment in tertiary care sample. In conclusion, the P-CPG is an appropriate measure of pain severity in children and adolescents with chronic pain in clinical as well as epidemiological settings.

Latent Profile Analysis of Canadian Military Veterans With Chronic Pain Identifies 5 Meaningful Classes Through Self-Report Measures.

The purpose of this study was to identify meaningful response patterns in self-report survey data collected from Canadian military veterans with chronic pain and to create an algorithm intended to facilitate triage and prioritization of veterans to the most appropriate interventions. An online survey was presented to former members of the Canadian military who self-identified as having chronic pain. Variables collected were related to pain, physical and mental interference, prior traumatic experiences, and indicators from each of the 7 potential drivers of the pain experience. Maximum likelihood estimation-based latent profile analysis was used to identify clinically and statistically meaningful profiles using the 7-axis variables, and classification and regression tree (CRT) analysis was then conducted to identify the most parsimonious set of indicators that could be used to accurately classify respondents into the most relevant profile group. Data from N = 322 veterans were available for analysis. The results of maximum likelihood estimation-based latent profile analysis indicated a 5-profile structure was optimal for explaining the patterns of responses within the data. These were: Mood-Dominant (13%), Localized Physical (24%), Neurosensory-Dominant (33%), Central-Dominant with complex mood and neurosensory symptoms (16%), and Trauma- and mood-dominant (14%). From CRT analysis, an algorithm requiring only 3 self-report tools (central symptoms, mood screening, bodily coherence) achieved 83% classification accuracy across the 5 profiles. The new classification algorithm requiring 16 total items may be helpful for clinicians and veterans in pain to identify the most dominant drivers of their pain experience that may be useful for prioritizing intervention strategies, targets, and relevant health care disciplines. PERSPECTIVE: This article presents the results of latent profile (cluster) analysis of responses to standardized self-report questionnaires by Canadian military veterans with chronic pain. It identified 5 clusters that appear to represent different drivers of the pain experience. The results could be useful for triaging veterans to the most appropriate pain care providers.

[Chronic Pain: Definition/Conception/Classification of Pain].

Understanding what pain is necessary to understand the pathomechanisms of chronic pain. The International Association for the Study of Pain (IASP) defines pain as "An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage" and its further states that pain is a personal experience, influenced to varying degrees by biological, psychological, and social factors. It also mentions that person learn the concept of the pain through life experiences, and that it does not always play an adaptive role and has a negative impact on our physical, social, and psychological health. In order to classify chronic pain, IASP created a coding system in ICD11 that focuses on chronic secondary pain, which has clear organic factors, and chronic primary pain, which is difficult to explain from the organic aspect alone. When considering pain treatment, it is necessary to consider three pain mechanisms, including nociceptive pain, neuropathic pain, and nociplastic pain, which is a condition in which the patient feels strong pain due to sensitization of the nervous system.

Characteristics of clusters with contrasting relationships between central sensitization-related symptoms and pain.

The central sensitization inventory (CSI) evaluates the central sensitization (CS)-related symptoms associated with increased pain sensitivity. However, the CSI includes items that are not directly related to pain. In this study, 146 patients with pain were classified into subgroups by k-means cluster analysis based on the short form of the central sensitization inventory (CSI9) and pain scores. In addition, inter-group and multiple comparisons were performed to examine the characteristics of each group. As a result of this study, there were three subgroups (clusters 1, 2, and 3) in which the CSI9 and pain intensity were both low, moderate, and high, and one subgroup (cluster 4) in which only CSI9 was high and pain intensity was low. Two subgroups with high CSI9 scores but contrasting pain intensities (clusters 3 and 4) were extracted; the pattern of CS-related symptoms in these two groups was very similar, with no differences in most of the non-pain factors. It is necessary to consider these points when interpreting the clinical condition of a patient with pain when using the assessment of CS-related symptoms.

Muscle network topology analysis for the classification of chronic neck pain based on EMG biomarkers extracted during walking.

Neuromuscular impairments are frequently observed in patients with chronic neck pain (CNP). This study uniquely investigates whether changes in neck muscle synergies detected during gait are sensitive enough to differentiate between people with and without CNP. Surface electromyography (EMG) was recorded from the sternocleidomastoid, splenius capitis, and upper trapezius muscles bilaterally from 20 asymptomatic individuals and 20 people with CNP as they performed rectilinear and curvilinear gait. Intermuscular coherence was computed to generate the functional inter-muscle connectivity network, the topology of which is quantified based on a set of graph measures. Besides the functional network, spectrotemporal analysis of each EMG was used to form the feature set. With the use of Neighbourhood Component Analysis (NCA), we identified the most significant features and muscles for the classification/differentiation task conducted using K-Nearest Neighbourhood (K-NN), Support Vector Machine (SVM), and Linear Discriminant Analysis (LDA) algorithms. The NCA algorithm selected features from muscle network topology as one of the most relevant feature sets, which further emphasize the presence of major differences in muscle network topology between people with and without CNP. Curvilinear gait achieved the best classification performance through NCA-SVM based on only 16 features (accuracy: 85.00%, specificity: 81.81%, and sensitivity: 88.88%). Intermuscular muscle networks can be considered as a new sensitive tool for the classification of people with CNP. These findings further our understanding of how fundamental muscle networks are altered in people with CNP.

Distinguishing chronic low back pain in young adults with mild to moderate pain and disability using trunk compliance.

Chronic low back pain (cLBP) rates among younger individuals are rising. Although pain and disability are often less severe, underlying changes in trunk behavior may be responsible for recurrence. We examine the biomarker capacity of a simple Trunk Compliance Index (TCI) to distinguish individuals with and without cLBP. A random subset (n = 49) of the RELIEF RCT were matched to healthy controls for sex, age, height and weight. We measured TCI (as displacement/ weight-normalized perturbation force) using anthropometrically-matched, suddenly-applied pulling perturbations to the trunk segment, randomized across three planes of motion (antero-posterior, medio-lateral, and rotational). Mean differences between cLBP, sex and perturbation direction were assessed with repeated-measures analysis of variance. Discriminatory accuracy of TCI was assessed using Receiver Operator Characteristic (ROC) analysis. Baseline characteristics between groups were equivalent (x̅ [range]): sex (57% female / group), age (23.0 [18-45], 22.8 [18-45]), height, cm (173.0 [156.5-205], 171.3 [121.2-197], weight, kg (71.8 [44.5-116.6], 71.7 [46.8-117.5]) with cLBP associated with significantly lower TCI for 5 of 6 directions (range mean difference, - 5.35: - 1.49, range 95% CI [- 6.46: - 2.18 to - 4.35: - 0.30]. Classification via ROC showed that composite TCI had high discriminatory potential (area under curve [95% CI], 0.90 [0.84-0.96]), driven by TCI from antero-posterior perturbations (area under curve [95% CI], 0.99 [0.97-1.00]). Consistent reductions in TCI suggests global changes in trunk mechanics that may go undetected in classic clinical examination. Evaluation of TCI in younger adults with mild pain and disability may serve as a biomarker for chronicity, leading to improved preventative measures in cLBP.Trial Registration and Funding RELIEF is registered with clinicaltrials.gov (NCT01854892) and funded by the NIH National Center for Complementary & Integrative Health (R01AT006978).

Nerve Pain after Burn Injury: A Proposed Etiology-Based Classification.

BACKGROUND: Understanding the mechanism of nerve injury may facilitate managing burn-related nerve pain. This proposed classification, based on cause of nerve injury, was developed to enhance the understanding and management of burn-related nerve pain. METHODS: This retrospective investigation included patients aged 15 years or older admitted to the burn center from 2014 to 2019. Burn-related nerve pain was patient-reported and clinically assessed as pain 6 months or more after burn injury, unrelated to preexisting illnesses/medications. The pain classification consisted of direct nerve injury, nerve compression, electrical injury, and nerve dysfunction secondary to systemic injury. The four categories were statistically analyzed between groups, using 52 variables. RESULTS: Of the 1880 consecutive burn patients, 113 developed burn-related nerve pain and were eligible for validation of the classification: direct nerve injury, n = 47; nerve compression, n = 12; electrical injury, n = 7; and nerve dysfunction secondary to systemic injury, n = 47. Factors, significantly increased, that distinguished one category from another were as follows: for direct nerve injury, continuous symptoms (p < 0.001), refractory nerve release response (p < 0.001), nerve repair (p < 0.001), and pruritus (p < 0.001); for nerve compression, Tinel signs (p < 0.001), shooting pain (p < 0.001), numbness (p = 0.003), intermittent symptoms (p < 0.001), increased percentage total body surface area burned (p = 0.019), surgical procedures (p < 0.001), and nerve release (p < 0.001); and for electrical injury, Tinel sign (p < 0.001), intermittent symptoms (p = 0.002), amputations (p = 0.002), fasciotomies (p < 0.001), and nerve release (p < 0.001). Nerve dysfunction secondary to systemic injury was distinguished by significantly less Tinel signs (p < 0.001), shooting pain (p < 0.001), numbness and tingling (p < 0.001), pruritus (p < 0.001), fascial excision (p = 0.004), skin grafts (p < 0.001), amputation (p = 0.004), nerve releases (p < 0.001), and third-degree burns (p = 0.002). CONCLUSION: A classification consisting of direct nerve injury, nerve compression, electrical injury, and nerve dysfunction secondary to systemic injury is presented that may guide patient management and research methods, with the goal of improving pain outcomes in burn-related nerve pain.

Less is More: Five-item Neck Disability Index to Assess Chronic Neck Pain Patients in Brazil.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: The aim of this study was to assess the structural validity of the Brazilian version of the Neck Disability Index (NDI) in patients with chronic neck pain. SUMMARY OF BACKGROUND DATA: NDI is widely used in clinical and scientific contexts, although its structure has not been evaluated in the Brazilian version. METHODS: Native Brazilian Portuguese speakers, aged ≥18 years, with neck pain complaint of at least 3 months, and minimal pain rating of 3 points at rest or during neck movements were included. Exploratory factorial analysis (EFA) and confirmatory factorial analysis (CFA) were used. In EFA, the adequacy of the model was assessed using Bartlett test of sphericity and Kaiser-Meyer-Olkin test. In CFA, the goodness-of-fit was assessed by the indices: root mean square error of approximation with 90% of confidence interval, comparative fit index, Tucker-Lewis Index, standardized root mean square residual, and χ2/degree of freedom. Akaike information criterion (AIC) and Bayesian information criterion (BIC) were considered to compare the models. RESULTS: Two hundred fifty-four participants with chronic neck pain were included. The NDI model with one domain and five items presented the most adequate goodness-of-fit indexes and the lowest values of AIC and BIC, when compared with models with one domain and 10, eight, or seven items, and with the model with two domains and 10 items. CONCLUSION: In the Brazilian context, the NDI version with one domain and five items (personal care, concentration, work, driving, and recreation) presents the best structure according to the factorial analysis.Level of Evidence: 5.

Triaging Interventional Pain Procedures During COVID-19 or Related Elective Surgery Restrictions: Evidence-Informed Guidance from the American Society of Interventional Pain Physicians (ASIPP).

BACKGROUND: The COVID-19 pandemic has worsened the pain and suffering of chronic pain patients due to stoppage of "elective" interventional pain management and office visits across the United States. The reopening of America and restarting of interventional techniques and elective surgical procedures has started. Unfortunately, with resurgence in some states, restrictions are once again being imposed. In addition, even during the Phase II and III of reopening, chronic pain patients and interventional pain physicians have faced difficulties because of the priority selection of elective surgical procedures.Chronic pain patients require high intensity care, specifically during a pandemic such as COVID-19. Consequently, it has become necessary to provide guidance for triaging interventional pain procedures, or related elective surgery restrictions during a pandemic. OBJECTIVES: The aim of these guidelines is to provide education and guidance for physicians, healthcare administrators, the public and patients during the COVID-19 pandemic. Our goal is to restore the opportunity to receive appropriate care for our patients who may benefit from interventional techniques. METHODS: The American Society of Interventional Pain Physicians (ASIPP) has created the COVID-19 Task Force in order to provide guidance for triaging interventional pain procedures or related elective surgery restrictions to provide appropriate access to interventional pain management (IPM) procedures in par with other elective surgical procedures. In developing the guidance, trustworthy standards and appropriate disclosures of conflicts of interest were applied with a section of a panel of experts from various regions, specialties, types of practices (private practice, community hospital and academic institutes) and groups. The literature pertaining to all aspects of COVID-19, specifically related to epidemiology, risk factors, complications, morbidity and mortality, and literature related to risk mitigation and stratification was reviewed. The evidence -- informed with the incorporation of the best available research and practice knowledge was utilized, instead of a simplified evidence-based approach. Consequently, these guidelines are considered evidence-informed with the incorporation of the best available research and practice knowledge. RESULTS: The Task Force defined the medical urgency of a case and developed an IPM acuity scale for elective IPM procedures with 3 tiers. These included urgent, emergency, and elective procedures. Examples of urgent and emergency procedures included new onset or exacerbation of complex regional pain syndrome (CRPS), acute trauma or acute exacerbation of degenerative or neurological disease resulting in impaired mobility and inability to perform activities of daily living. Examples include painful rib fractures affecting oxygenation and post-dural puncture headaches limiting the ability to sit upright, stand and walk. In addition, emergency procedures include procedures to treat any severe or debilitating disease that prevents the patient from carrying out activities of daily living. Elective procedures were considered as any condition that is stable and can be safely managed with alternatives. LIMITATIONS: COVID-19 continues to be an ongoing pandemic. When these recommendations were developed, different stages of reopening based on geographical regulations were in process. The pandemic continues to be dynamic creating every changing evidence-based guidance. Consequently, we provided evidence-informed guidance. CONCLUSION: The COVID-19 pandemic has created unprecedented challenges in IPM creating needless suffering for pain patients. Many IPM procedures cannot be indefinitely postponed without adverse consequences. Chronic pain exacerbations are associated with marked functional declines and risks with alternative treatment modalities. They must be treated with the concern that they deserve. Clinicians must assess patients, local healthcare resources, and weigh the risks and benefits of a procedure against the risks of suffering from disabling pain and exposure to the COVID-19 virus.

Evolution of bodily distress disorders.

PURPOSE OF REVIEW: The nomenclature and classification of somatoform disorders have undergone revisions in the fifth edition of the Diagnostic and Statistical Manual (DSM 5) and the upcoming eleventh edition of the International Classification of Diseases (ICD-11). The present review describes the changes that have evolved and highlight the possible challenges. RECENT FINDINGS: Bodily distress disorders replace the term somatoform disorders. The emphasis on the symptoms to be medically unexplained has been removed. The need to have a certain number of symptoms associated with different organ systems has made way to the presence of one or more distressing bodily symptoms. The focus on psychological aspects like excessive attention, thoughts, and behaviors associated with bodily symptoms have been added to make it a more diagnosis of inclusion rather than exclusion. An additional qualifier of severity has been added, which highlights the importance of impairment associated with these symptoms. SUMMARY: The diagnostic criteria for bodily distress disorders is a step towards making the diagnostic criteria clinically useful and appears to be applicable across the healthcare settings. However, the ability to discern this diagnosis with the newly revised classification of chronic pain and the possibility of over psychologizing the medical disorders need to be researched.

Description and classification of postpartum chronic pain: A multicentric prospective study.

INTRODUCTION: To classify persistent perineal and pelvic postpartum pain using the classification usually employed in chronic pelvic pain. MATERIAL AND METHOD: Prospective observational study including all women who have consulted an algologist or gynecologist at one of the six French centers for a chronic pain (superior or equal to 3 months) spontaneous linked by the mother with her childbirth were included. During semi-directed interviews, a questionnaire regarding sociodemographic factors and detailed questions about pain were collected. Then, pelvic and perineal pain were classified into 7 pain syndromes: pelvic sensitization (Convergences PP criteria), complex regional pain syndrome (Budapest criteria), pudendal or cluneal neuralgia (Nantes criteria), neuroma, thoraco-lumbar junction syndrome, myofascial pain (muscle trigger zone), fibromyalgia (American College of Rheumatology criteria). The principal objective of this study is to assess the prevalence of each painful disorder. The secondary aims were the description of socio-demographic factors and clinical characteristics of this population, identify the related symptoms and the impact on daily function associated with the chronic pelvic or perineal postpartum pain. RESULTS: 40 women with chronic pelvic or perineal pain spontaneously linked with childbirth were included. 78 % experienced pain for more than 12 months. A large majority had a vaginal birth (95 %) with perineal suture (90 %) and severe acute pain within the first week postpartum (62 %). Postpartum pain impacted participant's sexual activity (80 %), micturition (28 %) and defecation (38 %). In the sample, 17 cases of neuroma, 6 patients with pudendal or cluneal neuralgia, 13 patients with pelvic sensitization and 2 cases of fibromyalgia were identified. Complex regional pain syndrome was diagnosed in 8 patients, and myofascial pain in 11 women, and only 1 patient had thoraco-lumbar junction syndrome. Neuropathic pain was found in 31 participants (77.5 %) according to DN4 criteria. DISCUSSION: The classification scheme proposed in this study may be a very useful tool to investigate postpartum pelvic and perineal pain and to propose a treatment.

Factors Influencing Pain Dimensions in Patients with Chronic Tension-Type Headache: An Exploratory Survey.

BACKGROUND: Chronic tension type headache (CTTH) is one of the common cause of hospital visits among adolescents and adults. Chronic tension type headache produces pain, sleep disturbances, and disability among patients leading to a poor quality of life. Knowledge pattern of headache and various associated factors will aid appropriate management. AIMS: To identify the headache dimensions and their various influencing factors among patients of chronic tension-type headache. METHODS: Using consecutive sampling techniques, 169 patients with chronic tension-type headache were recruited in this cross-sectional survey. Approval was obtained from the Institute's Ethics Committee. The Wong-Baker Foundation Pain intensity scale was used to assess the pain severity. RESULTS: A pain severity score of 6 out of 10 was reported by 56% of the patients, and the mean pain score reported by the patients was 6.62 ± 1.16. The mean weekly headache frequency was 4.95 ± 0.38, and the mean daily headache duration was 8.68 ± 1.68 hours. Significantly more patients who are married, patients who had a duration of illness less than two years, and patients who were treated with only analgesics reported higher headache severity. Higher headache frequency was reported by significantly more patients who were male, married, from a nuclear family, educated, unskilled laborers or employed, urban inhabitants, or only on analgesics, or had illness duration less than two years. Headache duration was significantly higher in patients who were unskilled laborers or only on analgesics, or had illness duration less than two years. CONCLUSIONS: Patients with chronic tension-type headache experience moderate to high severity of headache, along with substantial duration and frequency, an outcome that was associated with various lifestyle-related factors that can result in stress. Lifestyle modification and nonpharmacological management are thus essential to reduce the severity, frequency, and duration of headache in patients with a chronic tension-type headache and medication overuse.

Diagnosis of fibromyalgia: comparison of the 2011/2016 ACR and AAPT criteria and validation of the modified Fibromyalgia Assessment Status.

OBJECTIVE: To compare the concordance of the three diagnostic criteria, respectively the 2011 ACR criteria (ACR 2011 Cr), the ACR 2016 criteria (ACR 2016 Cr) and the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION)-APS Pain Taxonomy criteria (AAPT Cr), and to explore the performance of an additional set of criteria, the modified Fibromyalgia Assessment Status (FAS 2019 modCr), in the diagnosis of FM syndrome. METHODS: Consecutive patients with chronic widespread pain, referred by the primary care setting, underwent rheumatologic assessment that established the presence or not of FM and were investigated through the four sets of proposed criteria. For the FAS 2019 modCr, discriminant validity to distinguish patients with FM and non-FM was assessed with receiver operating characteristic curve analysis. RESULTS: A total of 732 (405 with FM and 327 with other common chronic pain problems) patients were evaluated. Against the clinical diagnosis of FM, the sensitivity, specificity and correct classification were, respectively: 79.8, 91.7 and 85.1% for ACR 2011 Cr; 78, 90.5 and 83.6% for the ACR 2016 Cr; and 73.8, 91.7 and 81.8% for the AAPT Cr. The alternative set, proposed on the FAS 2019 modCr, provided a maximal diagnostic accuracy with a score ≥20 (Youden's index), with a sensitivity of 84.2%, specificity 89.0% and positive likelihood ratio 7.65. CONCLUSION: There is a considerable agreement between criteria-based diagnoses of FM, although the AAPT Cr perform least well in terms of percentage of correct classification. The FAS 2019 modCr had comparable characteristics.

Chronic orofacial pain.

While pain chronicity in general has been defined as pain lasting for more than 3 months, this definition is not useful in orofacial pain (OFP) and headache (HA). Instead, chronicity in OFP and HA is defined as pain occurring on more than 15 days per month and lasting for more than 4 h daily for at least the last 3 months. This definition excludes the periodic shortlasting pains that often recur in the face and head, but are not essentially chronic. Although the headache field has adopted this definition, chronic orofacial pain is still poorly defined. In this article, we discuss current thinking of chronicity in pain and examine the term 'chronic orofacial pain' (COFP). We discuss the entities that make up COFP and analyze the term's usefulness in clinical practice and epidemiology.

Initial classification of low back and leg pain based on objective functional testing: a pilot study of machine learning applied to diagnostics.

OBJECTIVE: The five-repetition sit-to-stand (5R-STS) test was designed to capture objective functional impairment and thus provided an adjunctive dimension in patient assessment. The clinical interpretability and confounders of the 5R-STS remain poorly understood. In clinical use, it became apparent that 5R-STS performance may differ between patients with lumbar disk herniation (LDH), lumbar spinal stenosis (LSS) with or without low-grade spondylolisthesis, and chronic low back pain (CLBP). We seek to evaluate the extent of diagnostic information contained within 5R-STS testing. METHODS: Patients were classified into gold standard diagnostic categories based on history, physical examination, and imaging. Crude and adjusted comparisons of 5R-STS performance were carried out among the three diagnostic categories. Subsequently, a machine learning algorithm was trained to classify patients into the three categories using only 5R-STS test time and patient age, gender, height, and weight. RESULTS: From two prospective studies, 262 patients were included. Significant differences in crude and adjusted test times were observed among the three diagnostic categories. At internal validation, classification accuracy was 96.2% (95% CI 87.099.5%). Classification sensitivity was 95.7%, 100%, and 100% for LDH, LSS, and CLBP, respectively. Similarly, classification specificity was 100%, 95.7%, and 100% for the three diagnostic categories. CONCLUSION: 5R-STS performance differs according to the etiology of back and leg pain, even after adjustment for demographic covariates. In combination with machine learning algorithms, OFI can be used to infer the etiology of spinal back and leg pain with accuracy comparable to other diagnostic tests used in clinical examination. These slides can be retrieved under Electronic Supplementary Material.

AAPT Diagnostic Criteria for Chronic Low Back Pain.

Chronic low back pain (CLBP) conditions are highly prevalent and constitute the leading cause of disability worldwide. The Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION) public-private partnership with the US Food and Drug Administration and the American Pain Society (APS), have combined to create the ACTTION-APS Pain Taxonomy (AAPT). The AAPT initiative convened a working group to develop diagnostic criteria for CLBP. The working group identified 3 distinct low back pain conditions which result in a vast public health burden across the lifespan. This article focuses on: 1) the axial predominant syndrome of chronic musculoskeletal low back pain, 2) the lateralized, distally-radiating syndrome of chronic lumbosacral radicular pain 3) and neurogenic claudication associated with lumbar spinal stenosis. This classification of CLBP is organized according to the AAPT multidimensional framework, specifically 1) core diagnostic criteria; 2) common features; 3) common medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors. PERSPECTIVE: An evidence-based classification of CLBP conditions was constructed for the AAPT initiative. This multidimensional diagnostic framework includes: 1) core diagnostic criteria; 2) common features; 3) medical and psychiatric comorbidities; 4) neurobiological, psychosocial, and functional consequences; and 5) putative neurobiological and psychosocial mechanisms, risk factors, and protective factors.