Predictors for severe persisting pain in rheumatoid arthritis are associated with pain origin and appraisal of pain.

OBJECTIVES: To determine the proportion of patients with rheumatoid arthritis (RA) with severe persisting pain and to identify predictive factors despite treatment-controlled disease activity. METHODS: This prospective multicentre study included outpatients with RA scheduled for escalation of anti-inflammatory treatment due to active disease and severe pain (Disease Activity Score 28 (DAS28)>3.2 and Visual Analogue Scale (VAS)>50). At week 24, patients were stratified into reference group (DAS28 improvement>1.2 or DAS28≤3.2 and VAS pain score<50), non-responders (DAS28 improvement≤1.2 and DAS28>3.2, regardless of VAS pain score) and persisting pain group (DAS28 improvement>1.2 or DAS28≤3.2 and VAS pain score≥50). The former two subgroups ended the study at week 24. The latter continued until week 48. Demographic data, DAS28-C reactive protein, VAS for pain, painDETECT Questionnaire (PD-Q) to identify neuropathic pain (NeP) and the Pain Catastrophising Scale were assessed and tested for relation to persisting pain. RESULTS: Of 567 patients, 337 (59.4%) were classified as reference group, 102 (18.0%) as non-responders and 128 (22.6%) as patients with persisting pain. 21 (8.8%) responders, 28 (35.0%) non-responders and 27 (26.5%) persisting pain patients tested positive for NeP at week 24. Pain catastrophising (p=0.002) and number of tender joints (p=0.004) were positively associated with persisting pain at week 24. Baseline PD-Q was not related to subsequent persisting pain. CONCLUSIONS: Persisting and non-nociceptive pain occur frequently in RA. Besides the potential involvement of NeP, pain catastrophising and a higher number of tender joints coincide with persisting pain.

Global Functioning in Axial Spondyloarthritis is Stronger Associated With Disease Activity and Function Than With Mobility and Radiographic Damage.

OBJECTIVE: The Assessment of Spondyloarthritis International Society Health Index (ASAS HI) is a validated patient-reported outcome (PRO) for global functioning of patients with axial spondyloarthritis (axSpA). The Epionics SPINE (ES) is an electronic device for assessment of axial mobility that provides an objective measure of spinal mobility by assessing range of motion (RoM) and range of kinematics (RoK). The aim of this study is to investigate the relationship between global functioning and clinical measures of disease activity, physical function, spinal mobility, and radiographic damage. METHODS: In a cross-sectional study design, consecutive patients with radiographic and nonradiographic axSpA were included, and the following established tools were assessed: Bath ankylosing spondylitis (AS) disease activity index (BASDAI), Bath AS functional index (BASFI), Bath AS metrology index (BASMI), ASAS HI, and RoM and RoK using ES. Structural damage of spine and sacroiliac joints (SIJ) were assessed by counting the number of syndesmophytes and by New York grading of sacroiliitis. Kendall's tau correlation coefficients were calculated. RESULTS: In 103 patients with axSpA, ASAS HI scores correlated significantly with PRO scores (BASDAI, r = 0.36; BASFI, r = 0.48; and back pain, r = 0.41; all P < 0.001). In contrast, no significant correlation between ASAS HI and RoM and RoK (r between -0.08 and 0.09) and radiographic damage in SIJ and spine (all r between 0.03 and 0.004) were seen, respectively. BASMI scores correlated weakly (r = 0.14; P = 0.05). CONCLUSION: This study shows that axSpA disease-specific PROs have an impact on global functioning, whereas spinal mobility scores, even if objectively assessed by the ES, have limited impact on patient reported-global functioning. The results also suggest that global functioning is, in this cohort, not much dependent on the degree of structural damage in the axial skeleton.

Clinical Relevance of Axial Radiographic Damage in Axial Spondyloarthritis: Evaluation of Functional Consequences by an Objective Electronic Device.

OBJECTIVE: Axial spondyloarthritis (axSpA) is associated with decreased function and mobility of patients as a result of inflammation and radiographic damage. The Epionics SPINE device (ES), an electronic device that objectively measures spinal mobility, including range of motion (RoM) and speed (ie, range of kinematics [RoK]) of movement, has been clinically validated in axSpA. We investigated the performance of the ES relative to radiographic damage in the axial skeleton of patients with axSpA. METHODS: A total of 103 patients with axSpA, 31 with nonradiographic axSpA (nr-axSpA) and 72 with radiographic axSpA (r-axSpA), were consecutively examined. Conventional radiographs of the spine (including presence, number, and location of syndesmophytes) and the sacroiliac joints (SIJs; rated by the modified New York criteria) were analyzed with the ES. Function and mobility were assessed using analyses of covariance and Spearman correlation. RESULTS: The number of syndesmophytes correlated positively with Bath Ankylosing Spondylitis Metrology Index scores (r 0.38, P = 0.02) and correlated negatively with chest expansion (r -0.39, P = 0.02) and ES measurements (-0.53 ≤ r ≤ -0.34, all P < 0.03), except for RoM and RoK regarding rotation and RoK for extension of the lumbar and thoracic spines. In the radiographic evaluation of the SIJs, the extent of damage correlated negatively with ES scores and metric measurements (-0.49 ≤ r ≤ -0.33, all P < 0.001). Patients with r-axSpA, as compared to those with nr-axSpA, showed significantly worse ES scores for RoM, RoK, and chest expansion. CONCLUSION: The ES scores, in accordance with mobility measurements, correlated well with the presence and extent of radiographic damage in the spine and the SIJs. As expected, patients with r-axSpA had more severe impairments than those with nr-axSpA.

Successful Evaluation of Spinal Mobility Measurements With the Epionics SPINE Device in Patients With Axial Spondyloarthritis Compared to Controls.

OBJECTIVE: Epionics SPINE (ES), a novel device that measures spinal movements using electronic sensors including range of motion (RoM) and speed (range of kinematics [RoK]), has already been validated in patients with mechanical back pain and healthy individuals. This study aimed to evaluate ES for quantification of spinal mobility in patients with axial spondyloarthritis (axSpA). METHODS: A total of 153 individuals, 39 female and 114 male, were examined including 134 patients with axSpA, of whom 40 had nonradiographic (nr)-axSpA, 94 had radiographic (r)-axSpA; 19 were healthy controls (HCs). The results were compared using mean ES scores and modeling was performed using multivariable logistic regression models resulting in good validity and high discriminative power. RESULTS: ES measurements showed meaningful differences between patients with axSpA and HCs (all P < 0.001), as well as between r- and nr-axSpA (P < 0.01). In patients with axSpA, a negative correlation between ES and Bath Ankylosing Spondylitis Metrology Index values was found: -0.76 ≤ r ≤ -0.52 (P < 0.05). Bath Ankylosing Spondylitis Functional Index scores showed a similar trend (r > -0.39). Patients with r-axSpA had a more limited and slower spinal mobility than those with nr-axSpA. Other patient-reported outcomes almost did not correlate. CONCLUSION: This study shows that the ES is an objective performance measure and a valid tool to assess spinal mobility in axSpA, also based on the Outcomes Measures in Rheumatology (OMERACT) criteria. RoK and RoM scores provide additional information on physical function of patients with axSpA.

Screening of neuropathic pain components in patients with chronic back pain associated with nerve root compression: a prospective observational pilot study (MIPORT).

OBJECTIVE: Chronic back pain is characterized by a combination of neuropathic and nociceptive mechanisms of pain generation. The prevalence of the neuropathic pain component is unknown. Thus, in the context of an explorative study, we aimed to determine the prevalence of signs and symptoms indicating neuropathic pain in adult patients treated by orthopaedists. We also aimed to assess the usefulness of handheld computers (PDAs) in data collection. METHODS: Prospective epidemiological study in 18 orthopaedic practices or centres throughout Germany. Physician and patient questionnaires (paper/pencil or on handheld computers, PDAs) for patients with back pain of at least 3 months in duration were applied, as well as the von Korff score to assess pain intensity (visual analogue scale, VAS; 0 = no pain, 10 = worst possible pain) and pain characteristics, the Hannover Functional Ability Questionnaire (FFbH-R), and if patients agreed to provide information, the short-form Patient Health Questionnaire (PHQ-D) for depression. RESULTS: For 717 patients, both patient and physician questionnaires were available. Mean patient age was 56 years; pain was predominantly located in the low back (87%). Median current pain intensity on the VAS was 5.0. Confirmed key signs and symptoms indicated neuropathic pain was frequent, e.g. radicular pain radiating beyond the knee towards the foot (40.0%), positive Lasegue sign (18.4%), or absent patellar reflex (17.3%). A third of all patients (33.5%) had >or=3 characteristic signs for neuropathic pain. Patient functionality was severely reduced (median 43.3%). There were no relevant differences in outcomes between patients using the paper/pencil method (47%) versus those preferring PDAs (53%). CONCLUSION: Screening for neuropathic pain in this setting is feasible with simple questionnaires and scales on PDAs. Neuropathic pain is a major contributor to chronic back pain and a frequent component in patients seen by orthopaedists. At least one third of all patients should undergo additional diagnostic measures to confirm the cause of neuropathic pain.

Chronic pain patients' treatment preferences: a discrete-choice experiment.

OBJECTIVE: The objective of this study was to identify, document, and weight attributes of a pain medication that are relevant from the perspective of patients with chronic pain. Within the sub-population of patients suffering from "chronic neuropathic pain", three groups were analyzed in depth: patients with neuropathic back pain, patients with painful diabetic polyneuropathy, and patients suffering from pain due to post-herpetic neuralgia. The central question was: "On which features do patients base their assessment of pain medications and which features are most useful in the process of evaluating and selecting possible therapies?" METHODS: A detailed literature review, focus groups with patients, and face-to-face interviews with widely recognized experts for pain treatment were conducted to identify relevant treatment attributes of a pain medication. A pre-test was conducted to verify the structure of relevant and dominant attributes using factor analyses by evaluating the most frequently mentioned representatives of each factor. The Discrete-Choice Experiment (DCE) used a survey based on self-reported patient data including socio-demographics and specific parameters concerning pain treatment. Furthermore, the neuropathic pain component was determined in all patients based on their scoring in the painDETECT(®) questionnaire. For statistical data analysis of the DCE, a random effect logit model was used and coefficients were presented. RESULTS: A total of 1,324 German patients participated in the survey, of whom 44 % suffered from neuropathic back pain (including mixed pain syndrome), 10 % complained about diabetic polyneuropathy, and 4 % reported pain due to post-herpetic neuralgia. A total of 36 single quality aspects of pain treatment, detected in the qualitative survey, were grouped in 7 dimensions by factor analysis. These 7 dimensions were used as attributes for the DCE. The DCE model resulted in the following ranking of relevant attributes for treatment decision: "no character change", "less nausea and vomiting", "pain reduction" (coefficient: >0.9 for all attributes, "high impact"), "rapid effect", "low risk of addiction" (coefficient ~0.5, "middle impact"), "applicability with comorbidity" (coefficient ~0.3), and "improvement of quality of sleep" (coefficient ~0.25). All attributes were highly significant (p < 0.001). CONCLUSIONS: The results were intended to enable early selection of an individualized pain medication. The results of the study showed that DCE is an appropriate means for the identification of patient preferences when being treated with specific pain medications. Due to the fact that pain perception is subjective in nature, the identification of patients´ preferences will enable therapists to better develop and implement patient-oriented treatment of chronic pain. It is therefore essential to improve the therapists´ understanding of patient preferences in order to make decisions concerning pain treatment. DCE and direct assessment should become valid instruments to elicit treatment preferences in chronic pain.