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Objectives: The objective of this study was to estimate the minimal important change (MIC) and responsiveness of core patient reported outcome measures for chronic low back pain (LBP) and Modic changes. Study Design and Setting: In the Antibiotics in Modic changes (AIM) trial we measured disability (RMDQ, ODI), LBP intensity (NRS) and health-related quality of life (EQ5D) electronically at baseline, three- and 12-month follow-up. MICs were estimated using Receiver Operating Curve (ROC) curve and Predictive modeling analyses against the global perceived effect. Credibility of the estimates was assessed by a standardized set of criteria. Responsiveness was assessed by a construct and criterion approach according to COSMIN guidelines. Results: The MIC estimates of RMDQ, ODI and NRS scores varied between a 15–40% reduction, depending on including “slightly improved” in the definition of MIC or not. The MIC estimates for EQ5D were lower. The credibility of the estimates was moderate. For responsiveness, five out of six hypotheses were confirmed and AUC was >0.7 for all PROMs. Conclusion: When evaluated in a clinical trial of patients with chronic LBP and Modic changes, MIC thresholds for all PROMs were on the lower spectrum of previous estimates, varying depending on the definition of MIC. Responsiveness was sufficient. publishedVersion

Lars Christian Haugli Bråten,1 Elisabeth Gjefsen,1,2 Kristina Gervin,1 Are Hugo Pripp,3 Jan Sture Skouen,4 Elina Schistad,5 Linda Margareth Pedersen,1 Monica Wigemyr,1 Kaja Kristine Selmer,1 Hans Christian Dalsbotten Aass,6 Guro Goll,7 Jens Ivar Brox,5 Ansgar Espeland,8,9 Lars Grøvle,10 John-Anker Zwart,1,2 Kjersti Storheim1,11 On behalf of The AIM-study group1Department of Research and Innovation, Division of Clinical Neuroscience, Oslo University Hospital HF, Oslo, Norway; 2Faculty of Medicine, University of Oslo, Oslo, Norway; 3Oslo Centre of Biostatistics and Epidemiology Research Support Services, Oslo University Hospital Ulleval, Oslo, Norway; 4Department of Physical Medicine and Rehabilitation, Haukeland University Hospital, Bergen, Norway; 5Department of Physical Medicine and Rehabilitation, Oslo University Hospital HF, Oslo, Norway; 6Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway; 7Center for Treatment of Rheumatic and Musculoskeletal Diseases (REMEDY), Diakonhjemmet Hospital, Oslo, Norway; 8Department of Radiology, Haukeland University Hospital, Bergen, Norway; 9Department of Clinical Medicine, University of Bergen, Bergen, Norway; 10Department of Rheumatology, Østfold Hospital Trust, Grålum, Norway; 11Oslo Metropolitan University, Department of Physiotherapy, Oslo, NorwayCorrespondence: Lars Christian Haugli Bråten, Tel +4722117769, Email l.c.h.braten@studmed.uio.noObjective: Randomized trials testing the effect of antibiotics for chronic low back pain (LBP) with vertebral bone marrow changes on MRI (Modic changes) report inconsistent results. A proposed explanation is subgroups with low grade discitis where antibiotics are effective, but there is currently no method to identify such subgroups. The objective of the present study was to evaluate whether distinct patterns of serum cytokine levels predict any treatment effect of oral amoxicillin at one-year follow-up in patients with chronic low back pain and Modic changes at the level of a previous lumbar disc herniation.Design: We used data from an overpowered, randomized, placebo-controlled trial (the AIM study) that tested 100 days of oral 750 mg amoxicillin vs placebo three times daily in hospital outpatients with chronic (> 6 months) LBP with pain intensity ≥ 5 on a 0– 10 numerical rating scale and Modic changes type 1 (oedema type) or 2 (fatty type). We measured serum levels of 40 inflammatory cytokines at baseline and analysed six predefined potential predictors of treatment effect based on cytokine patterns in 78 randomized patients; three analyses with recursive partitioning, one based on cluster analysis and two based on principal component analyses. The primary outcome was the Roland–Morris Disability Questionnaire score at one-year follow-up in the intention to treat population. The methodology and overall results of the AIM study were published previously.Results: The 78 patients were 25– 62 years old and 47 (60%) were women. None of the three recursive partitioning analyses resulted in any suggested subgroups. Of all main analyses, the largest effect estimate (mean difference between antibiotic and placebo groups) was seen in a subgroup not predefined as of main interest (Cluster category 3+4; − 2.0, 95% CI: − 5.2– 1.3, RMDQ points; p-value for interaction 0.54).Conclusion: Patterns of inflammatory serum cytokine levels did not predict treatment effect of amoxicillin in patients with chronic LBP and Modic changes.Clinical Trial Registration Number: ClinicalTrials.gov (identifier: NCT02323412).Keywords: low back pain, Modic changes, infection, cytokines, inflammation

Rescue medication (RM) consumption is commonly used as a secondary outcome in placebo-controlled trials of chronic pain, but its validity has yet to be established. If participants randomized to placebo take more RM than those randomized to an active drug, the difference in pain between the 2 groups may be reduced, potentially masking effects of the active drug. This study assessed proportional RM consumption in the placebo and active groups according to results of 42 randomized controlled trials of neuropathic pain (NeP), and 29 trials of low back pain, which were included in 2 systematic reviews and meta-analyses. Trial results were assessed based on effect size, statistical significance, and whether the drug was recommended as first-line treatment by the systematic reviews. In trials indicating effect of the investigational drug, RM consumption was generally higher in the placebo groups than in the active groups. In trials reporting a small or a medium effect size of the investigational drug, subjects receiving placebo consumed 17% to 30% more RM than subjects receiving active drug, potentially leading to underestimation of the effects of the investigational drugs. Few trials reported a large effect size. Differences in RM consumption between participants receiving placebo and those receiving active drug were seldom taken in account by the individual trials and not at all by the systemic reviews when making treatment recommendations for NeP or low back pain. Elaboration on analytical methods to assess treatment effects in chronic pain trials using RM is warranted.

Background The frequency with which sensory disturbances occur in patients with radicular leg pain and disc herniation is not well known, and the efficacy of tests to identify such changes are not firmly established. The presence of sensory disturbances is a key sign of nerve root involvement and may contribute to the diagnosis of a lumbar disc herniation, identify patients for referral to spinal imaging and surgery, and improve disease classification. Questions/purposes In this study, we sought: (1) to determine the frequency with which abnormal sensory findings occur in patients with lumbar disc herniation-related radicular pain, using a standard neurological sensory examination; (2) to determine what particular standard sensory test or combination of tests is most effective in establishing sensory dysfunction; and (3) to determine whether a more detailed in-depth sensory examination results in more patients being identified as having abnormal sensory findings. Methods Between October 2013 and April 2016, 115 patients aged 18 to 65 years referred to secondary health care with radicular leg pain and disc herniation were considered potentially eligible for inclusion in the study. Based on these inclusion criteria, 79% (91) were found eligible. Ten percent (11) were excluded because of other illness that interfered with the study purpose, 3% (3) because of cauda equina syndrome, 2% (2) because of spinal stenosis, 2% (2) because of prior surgery at the same disc level, and 2% (2) because of poor Norwegian language skills. Three percent (4) of the patients did not want to participate in the study. Of the 91 eligible patients, 56% (51) consented to undergo a comprehensive clinical examination and were used for analysis here. The sample for the purposes of the present study was predetermined at 50. These patients were first examined by a standard procedure, including sensory assessment of light touch, pinprick, vibration, and warmth and cold over the back and legs. Second, an in-depth semiquantitative sensory testing procedure was performed in the main pain area to assess sensory dysfunction and improve the detection of potential positive sensory signs, or sensory gain of function more precisely. Sensory loss was defined as sensations experienced as distinctly reduced in the painful side compared with the contralateral reference side. In contrast, sensory gain was defined as sensations experienced as abnormally strong, unpleasant, or painful and distinctly stronger than the contralateral side. Ambiguous test results were coded as a normal response to avoid inflating the findings. The proportions of abnormal findings were calculated for each sensory modality and for all combinations of the standard examination tests. Results The standard examination identified at least one abnormal finding in 88% (45 of 51) of patients. Sensory loss was present in 80% (41), while sensory gain was present in 35% (18). The combination of pinprick and light touch identified all patients who were classified as having abnormal findings by the full standard examination. The semiquantitative procedure identified an additional three patients with an abnormal finding. Conclusion We suggest that the combination of pinprick and light touch assessment is an adequate minimal approach for diagnostic and classification purposes in patients with lumbar radicular pain. Level of evidence Level I, diagnostic study.

Study Design. Exploratory subgroup analyses of a randomised trial (Antibiotics In Modic changes (AIM) study). Objective. To assess the effect of amoxicillin versus placebo in reducing Modic change (MC) oedema in patients with chronic low back pain (LBP). Summary of Background Data. The AIM study showed a small, clinically insignificant effect of amoxicillin on pain-related disability in patients with chronic LBP and MC type 1 (oedema type) on magnetic resonance imaging (MRI). Methods. A total of 180 patients were randomised to receive 100 days of amoxicillin or placebo. MC oedema was assessed on MRI at baseline and one-year follow-up. Per-protocol analyses were conducted in subgroups with MC oedema on short tau inversion recovery (STIR) or T1/T2-weighted MRI at baseline. MC oedema reductions (yes/no) in STIR and T1/T2-series were analysed separately. The effect of amoxicillin in reducing MC oedema was analysed using logistic regression adjusted for prior disc surgery. To assess the effect of amoxicillin versus placebo within the group with the most abundant MC oedema on STIR at baseline (‘STIR3’ group), we added age, STIR3 (yes/no), and STIR3×treatment group (interaction term) as independent variables and compared the marginal means (probabilities of oedema reduction). Results. Compared to placebo, amoxicillin did not reduce MC oedema on STIR (volume/intensity) in the total sample with oedema on STIR at baseline (odds ratio 1.0, 95% confidence interval (95%CI) [0.5, 2.0]; n=141) or within the STIR3 group (probability of oedema reduction 0.69, 95%CI [0.47, 0.92] with amoxicillin and 0.61, 95%CI [0.43, 0.80] with placebo; n=41). Compared with placebo, amoxicillin did not reduce MC oedema in T1/T2-series (volume of the type 1 part of MCs) (odds ratio 1.0, 95%CI [0.5, 2.3], n=104). Oedema declined in >50% of patients in both treatment groups. Conclusions. From baseline to one-year follow-up, amoxicillin did not reduce MC oedema compared with placebo. Level of Evidence. Level 2.

Chronic pain trials commonly allow auxiliary pain medications such as rescue and concomitant analgesics in addition to the randomized treatment. Changes in auxiliary pain medications after randomization represent intercurrent events that may affect either the interpretation or the existence of the measurements associated with the clinical question of interest, complicating the assessment of treatment efficacy. In chronic pain trials, pain intensity typically varies and patients may take the auxiliary medications 1 day but not the next or increase and decrease the dosages temporarily while continuing their randomized study medication. This distinctive feature of auxiliary pain medications as an intercurrent event has received little attention in the literature. Further clarifications on how to manage these issues are therefore pressing. Here we provide perspectives on issues related to auxiliary pain medication-related intercurrent events in randomized controlled chronic pain trials considering the strategies suggested in the E9(R1) addendum to the ICH guideline on statistical principles for clinical trials.

ObjectiveThe objective of the present study was to explore the diversity, quality, severity and distribution of symptoms in patients with radicular pain and a lumbar disc herniation.DesignLongitudinal cohort study.SettingHospital-based back clinic.ParticipantsNinety patients referred to secondary healthcare with (a) low back-related leg pain, (b) age between 18 and 65 years and (c) MRI confirmed lumbar disc herniation at a relevant side and level.Outcome measuresNeuropathic pain symptoms were assessed using the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) and the painDETECT Questionnaire. In a subsample classified with neuropathic pain, in-depth interviews were performed, and symptomatic areas were drawn on standardised body charts.ResultsAt baseline, the most frequently used painDETECT symptom descriptor was numbness sensation, reported by 94%, followed by sudden pain attacks and tingling or prickling. The mean (SD) SF-MPQ-2 score (0–10) for aching pain was 5.9 (2.8); numbness 4.3 (3.3); tingling 4.0 (3.4); burning 2.6 (3.1); pain caused by light touch 1.5 (2.6). Leg pain was rated as extremely bothersome by 73%, numbness and tingling by 38%, weakness by 24% and back pain by 17%. In the subsample (n=52), deep-lying pain and non-painful abnormal sensations were frequent, at 71% and 85%. Drawings demonstrated substantial overlap between symptoms from compromised L5 and the S1 nerve roots. Painful and non-painful symptoms improved at approximately the same rate. At the 1-year follow-up, 45% (14/31) of patients who had received disc surgery, and 34% (18/53) of those who had received conservative treatment reported no bothersome back pain, leg pain, numbness/tingling or weakness.ConclusionPatients reported several highly bothersome symptoms, but not all are described as painful. The overall symptom profile of lumbar disc-related radicular pain differs from other neuropathic pain conditions with limited allodynia and thermal hyperalgesia. Symptomatic areas for the L5 and S1 nerve roots have a large overlap.

To assess the 2-year effect on disease activity and health-related quality of life (HRQoL) of implementing a clinical practice treat-to-target (T2T) strategy in patients with rheumatoid arthritis (RA).Patients in the Norwegian Very Early Arthritis Cohort 2.0 (NOR-VEAC 2.0), included 2010-2015, were treated according to T2T principles with visits at baseline, 3, 6, 9, 12 months, then every 6 months plus monthly visits until DAS28 2.6. These patients were compared to a pre-T2T cohort of patients included in the Norwegian Disease Modifying Anti-Rheumatic Drug (NOR-DMARD) register 2006-2009. Both groups had a clinical diagnosis of RA (≤1 year) and were DMARD naïve. Disease activity and HRQoL outcomes were analysed, and the primary outcome was SDAI remission (≤3.3) at 2years.The T2T cohort included 293 patients (mean (SD) age 54 (13) years, 66% females, disease duration median (25,75 perc) 98 (57,164) days) and the routine care cohort 392 patients (age 54 (13) years, 68% females, 4 (0,30) days since diagnosis). At 2years, the proportion of patients achieving SDAI remission was 46% in the T2T cohort compared to 31% in the routine care cohort. EQ-5D was similar at baseline, but differed significantly between groups at 2years (median (25,75 perc) 0.77 (0.69, 0.85) vs 0.73 (0.59, 0.80), p 0.001). Methotrexate monotherapy was the dominant DMARD regimen used to achieve SDAI remission in both cohorts.Higher remission rates and better HRQoL were achieved in patients following a T2T strategy in clinical practice compared to routine care.

Study Design.Retrospective administrative database study.Objective.To assess temporal and regional trends, and length of hospital stay, in lumbar spinal stenosis (LSS) surgery in Norwegian public hospitals from 1999 to 2013.Summary of Background Data.Studies from several countries have reported incr

Objective To evaluate potential MRI-defined effect modifiers of amoxicillin treatment in patients with chronic low back pain and type 1 or 2 Modic changes (MCs) at the level of a previous lumbar disc herniation (index level). Methods In a prospective trial (AIM), 180 patients (25–64 years; mean age 45; 105 women) were randomised to receive amoxicillin or placebo for 3 months. Primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (0–24 scale) at 1 year. Mean RMDQ score difference between the groups at 1 year defined the treatment effect; 4 RMDQ points defined the minimal clinically important effect. Predefined baseline MRI features of MCs at the index level(s) were investigated as potential effect modifiers. The predefined primary hypothesis was a better effect of amoxicillin when short tau inversion recovery (STIR) shows more MC-related high signal. To evaluate this hypothesis, we pre-constructed a composite variable with three categories (STIR1/2/3). STIR3 implied MC-related STIR signal increases with volume ≥ 25% and height > 50% of vertebral body and maximum intensity increase ≥ 25% and presence on both sides of the disc. As pre-planned, interaction with treatment was analysed using ANCOVA in the per protocol population (n = 155). Results The STIR3 composite group (n = 41) and STIR signal volume ≥ 25% alone (n = 45) modified the treatment effect of amoxicillin. As hypothesised, STIR3 patients reported the largest effect (− 5.1 RMDQ points; 95% CI − 8.2 to − 1.9; p for interaction = 0.008). Conclusions Predefined subgroups with abundant MC-related index-level oedema on STIR modified the effect of amoxicillin. This finding needs replication and further support. Key Points • In the primary analysis of the AIM trial, the effect of amoxicillin in patients with chronic low back pain and type 1 or 2 MCs did not reach the predefined cut-off for clinical importance. • In the present MRI subgroup analysis of AIM, predefined subgroups with abundant MC-related oedema on STIR reported an effect of amoxicillin. • This finding requires replication and further support.

ObjectiveTo evaluate the cost–utility of 100 days of antibiotics in patients with chronic low back pain (LBP) and type I or II Modic changes included in the Antibiotic treatment In patients with chronic low back pain and Modic changes (AIM) study.DesignA cost–utility analysis from a societal and healthcare perspective alongside a double-blinded, parallel group, placebo, multicentre trial.SettingHospital outpatient clinics at six hospitals in Norway. The main results from the AIM study showed a small effect in back-related disability in favour of the antibiotics group, and slightly larger in those with type I Modic changes, but this effect was below the pre-defined threshold for clinically relevant effect.Participants180 patients with chronic LBP, previous disc herniation and Modic changes type I (n=118) or type II (n=62) were randomised to antibiotic treatment (n=89) or placebo-control (n=91).InterventionsOral treatment with either 750 mg amoxicillin or placebo three times daily for 100 days.Main outcome measuresQuality-adjusted life years (QALYs) by EuroQoL-5D over 12 months and costs for healthcare and productivity loss measured in Euro (€1=NOK 10), in the intention-to-treat population. Cost–utility was expressed in incremental cost-effectiveness ratio (ICER).ResultsMean (SD) total cost was €21 046 (20 105) in the amoxicillin group and €19 076 (19 356) in the placebo group, mean difference €1970 (95% CI; −3835 to 7774). Cost per QALY gained was €24 625. In those with type I Modic changes, the amoxicillin group had higher healthcare consumption than the placebo group, resulting in €39 425 per QALY gained. Given these ICERs and a willingness-to-pay threshold of €27 500 (NOK 275 000), the probability of amoxicillin being cost-effective was 51%. Even when the willingness-to-pay threshold increased to €55 000, the probability of amoxicillin being cost-effective was never higher than 53%.ConclusionsAmoxicillin treatment showed no evidence of being cost-effective for people with chronic LBP and Modic changes during 1-year follow-up.Trial registration numberClinicalTrials.govNCT02323412.

Background Low back-related leg pain with nerve root involvement is conceptually regarded as a neuropathic condition. However, it is uncertain to what extent patients with this condition can be formally classified with neuropathic pain. Method First, we used the 2016 revision of the IASP Special Interest Group on Neuropathic Pain (NeuPSIG) grading system for neuropathic pain to grade patients suffering from low back-related leg pain and a corresponding disc herniation with either unlikely, possible, probable or definite neuropathic pain. Examination included bedside quantitative sensory testing. Next, we used the clinical classification based on the 2016 NeuPSIG grading system as a reference standard to assess the ability of the painDETECT Questionnaire to identify patients with neuropathic pain. Results Of the 50 included patients, six (12%) fulfilled the clinical classification criteria for probable and 44 (88%) for definite neuropathic pain, while none were graded unlikely or possible. According to painDETECT, 23 patients (46%) were classified with unlikely neuropathic pain, 18 patients (36%) had an uncertain condition and in nine patients (18%) neuropathic pain was likely. Among the 44 patients graded as having definite neuropathic pain by the clinical classification, eight were classified as likely neuropathic pain by painDETECT, resulting in an agreement of 18%. Of these 44 patients graded with definite neuropathic pain, painDETECT classified 21 patients (48%) as unlikely and 15 (34%) as uncertain. Conclusion Our results do not support the use of painDETECT as a screening tool to classify or grade neuropathic components in patients with low back-related leg pain. Significance The painDETECT Questionnaire performed poorly at detecting neuropathic pain among patients with low back-related leg pain, compared to clinical examination based on the 2016 NeuPSIG grading system as a reference standard. Our results do not support the use of painDETECT as a screening tool to classify or grade neuropathic components in this population.

Background A previous randomised controlled trial (RCT) of patients with chronic low back pain (LBP) and vertebral bone marrow (Modic) changes (MCs) on magnetic resonance imaging (MRI), reported that a 3-month, high-dose course of antibiotics had a better effect than placebo at 12 months’ follow-up. The present study examines the effects of antibiotic treatment in chronic LBP patients with MCs at the level of a lumbar disc herniation, similar to the previous study. It also aims to assess the cost-effectiveness of the treatment, refine the MRI assessment of MCs, and further evaluate the impact of the treatment and the pathogenesis of MCs by studying genetic variability and the gene and protein expression of inflammatory biomarkers. Methods/design A double-blinded RCT is conducted at six hospitals in Norway, comparing orally administered amoxicillin 750 mg, or placebo three times a day, over a period of 100 days in patients with chronic LBP and type I or II MCs at the level of a MRI-confirmed lumbar disc herniation within the preceding 2 years. The inclusion will be stopped when at least 80 patients are included in each of the two MC type groups. In each MC type group, the study is designed to detect (β = 0.1, α = 0.05) a mean difference of 4 (standard deviation 5) in the Roland Morris Disability Questionnaire score between the two treatment groups (amoxicillin or placebo) at 1-year follow-up. The study includes cost-effectiveness measures. Blood samples are assessed for security measures and for possible inflammatory mediators and biomarkers at different time points. MCs are evaluated on MRI at baseline and after 12 months. A blinded intention-to-treat analysis of treatment effects will be performed in the total sample and in each MC type group. Discussion To ensure the appropriate use of antibiotic treatment, its effect in chronic LBP patients with MCs should be re-assessed. This study will investigate the effects and cost-effectiveness of amoxicillin in patients with chronic LBP and MCs at the level of a disc herniation. The study may also help to refine imaging and characterise the biomarkers of MCs. © The Author(s). 2017O. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver(http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

Objective.To examine the 2-year disease course in patients with undifferentiated arthritis (UA) focusing on fulfillment of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) rheumatoid arthritis (RA) classification criteria.Methods.Data were provided by the Norwegian Very Early Arthritis Clinic study, which included patients presenting with ≥ 1 swollen joint of ≤ 16 weeks’ duration. UA was defined as patients not fulfilling the 2010 ACR/EULAR RA criteria and who did not have a clinical diagnosis other than RA at baseline. The main outcome was fulfillment of the 2010 RA criteria. Secondary outcomes were disease-modifying antirheumatic drug (DMARD) use, resolution of synovitis without use of DMARD during followup, and final clinical diagnosis.Results.We included 477 patients with UA of whom 47 fulfilled the 2010 ACR/EULAR RA criteria during followup (UA-RA) and 430 did not (UA–non-RA). Of the UA-RA patients, 70% fulfilled the criteria within the first 6 months. UA-RA patients were older, more often positive for rheumatoid factor and anticitrullinated protein antibodies, female, and ever smokers, and they more often presented with polyarticular arthritis, small joint involvement, and a swollen shoulder joint. During followup, 53% of UA-RA patients vs 13% of UA-non-RA patients used DMARD (p < 0.001). Overall, 71% of patients with UA achieved absence of clinical synovitis at final followup without use of DMARD. The most frequent final clinical diagnosis was UA (61%).Conclusion.Only 9.8% of patients with UA fulfilled the 2010 RA criteria during 2-year followup. Small joint involvement and swollen shoulder joint were among the factors associated with RA development. In two-thirds of patients with UA, the arthritis resolved without use of DMARD.

Background Previous studies suggest that regulatory microRNAs (miRs) may modulate neuro-inflammatory processes. The purpose of the present study was to examine the role of miR-17 following intervertebral disc herniation. Methods In a cohort of 97 patients with leg pain and disc herniation verified on MRI, we investigated the association between circulating miR-17 and leg pain intensity. A rat model was used to examine possible changes in miR-17 expression in nucleus pulposus (NP) associated with leak of NP tissue out of the herniated disc. The functional role of miR-17 was addressed by transfection of miR-17 into THP-1 cells (human monocyte cell line). Results An association between the level of miR-17 in serum and the intensity of lumbar radicular pain was shown. Up-regulation of miR-17 in the rat NP tissue when applied onto spinal nerve roots and increased release of TNF following transfection of miR-17 into THP-1 cells were also observed. Hence, our data suggest that miR-17 may be involved in the pathophysiology underlying lumbar radicular pain after disc herniation. Conclusions We conclude that miR-17 may be associated with the intensity of lumbar radicular pain after disc herniation, possibly through a TNF-driven pro-inflammatory mechanism. Electronic supplementary material The online version of this article (10.1186/s13075-019-1967-y) contains supplementary material, which is available to authorized users.

This is the peer reviewed version of the following article: [Call for Caution in Using the Pain DETECT Questionnaire for Patient Stratification Without Additional Clinical Assessments: Comment on the Article by Soni et al. Arthritis & Rheumatology 71, 7 p1201-1202 (2019)], which has been published in final form at https://doi.org/10.1002/art.40804. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions: https://authorservices.wiley.com/author-resources/Journal-Authors/licensing/self-archiving.html#3. Deposited by shareyourpaper.org and openaccessbutton.org. We've taken reasonable steps to ensure this content doesn't violate copyright. However, if you think it does you can request a takedown by emailing help@openaccessbutton.org.

A prospective observational study with translation and psychometric analyses of a questionnaire.Cross-cultural adaptation of the Short-Form McGill Pain Questionnaire-2 into Norwegian.The different versions of the McGill Pain Questionnaire (MPQ) have been important and influential tools for pain assessment. To more reliably assess qualities of both neuropathic and non-neuropathic pain, the Short-Form MPQ was revised in 2009 (SF-MPQ-2), including seven additional descriptors. No Norwegian adaptation of the SF-MPQ-2 has been performed.A translation of the SF-MPQ-2 was performed based on established guidelines. Forward-translations were compared and discussed in an expert workgroup. A synthesis was achieved by consensus. A backward translation was reviewed and consolidated with the forward translations to confirm linguistic equivalence. A prefinal version was tested in eight patients, who were interviewed to evaluate acceptability and comprehension of the questionnaire. Minor changes were implemented. The questionnaire was externally proofread. The final Norwegian version (NSF-MPQ-2) was tested for content and construct validity and internal consistency reliability in a population with low back-related leg pain.The backward translation was in good accordance with the original version. The prefinal version showed excellent acceptability and comprehension in initial patient-testing. The NSF-MPQ-2 showed satisfactory content and construct validity, including responsiveness to change, and acceptable internal consistency reliability as measured by Cronbach's alpha. A confirmatory factor analysis showed poor fit for the established four-factor structure, especially regarding the neuropathic subscale.The NSF-MPQ-2 showed excellent acceptability and comprehension, satisfactory content and construct validity, including responsiveness to change, and internal consistency reliability as measured by Cronbach's alpha. However, a confirmatory factor analysis raised concerns regarding the factor-structure in the present population. Until more evidence emerges for the four-factor solution we suggest the NSF-MPQ-2 should be used as a single measure.3.

BACKGROUND Referral to secondary care is common for a considerable proportion of patients with persistent sciatica symptoms. It is unclear if information from clinical assessment can further identify distinct subgroups of disc-related sciatica, with perhaps different clinical courses. AIMS This study aims to identify and describe clusters of imaging confirmed disc-related sciatica patients using latent class analysis, and compare their clinical course. METHODS The study population were 466 patients with disc-related sciatica. Variables from clinical assessment were included in the analysis. Characteristics of the identified clusters were described and their clinical course over 2 years was compared. RESULTS A four-cluster solution was optimal. Cluster 1 (n = 110) had mild back and leg pain; cluster 2 (n = 59) had moderate back and leg pain; cluster 3 (n = 158) had mild back pain and severe leg pain; cluster 4 (n = 139) had severe back and leg pain. Patients in cluster 4 had the most severe profile in terms of disability, distress and comorbidity and the lowest reported global change and the smallest proportion of patients with a successful outcome at 2 years. Of the 135 patients who underwent surgery, 42% and 41% were in clusters 3 and 4, respectively. CONCLUSIONS Using a strict diagnosis of sciatica, this work identified four clusters of patients primarily differentiated by back and leg pain severity. Patients with severe back and leg pain had the most severe profile at baseline and follow-up irrespective of intervention. This simple classification system may be useful when considering prognosis and management with sciatica patients. SIGNIFICANCE Using data from a large observational prospective study, this work identifies four distinct clusters of patients with imaging confirmed disc-related sciatica. This classification could be used when considering prognosis and management with sciatica patients at their initial consultation.

BackgroundStudies from different Western countries have reported a rapid increase in spinal surgery rates, an increase that exceeds by far the growing incidence rates of spinal disorders in the general population. There are few studies covering all lumbar spine surgery and no previous studies from Norway.ObjectivesThe purpose of this study was to investigate trends in all lumbar spine surgery in Norway over 15 years, including length of hospital stay, and rates of complications and reoperations.DesignA longitudinal observational study over 15 years using hospital patient administrative data and sociodemographic data from the National Registry in Norway.Setting and participantsPatients aged ≥18 years discharged from Norwegian public hospitals between 1999 and 2013.Outcome measuresAnnual rates of simple (microsurgical discectomy, decompression) and complex surgical procedures (fusion, disc prosthesis) in the lumbar spine.ResultsThe rate of lumbar spine surgery increased by 54%, from 78 (95% CI (75 to 80)) to 120 (107 to 113) per 100 000, from 1999 to 2013. More men had simple surgery whereas more women had complex surgery. Among elderly people over 75 years, lumbar surgery increased by a factor of five during the 15-year period. The rates of complications were low, but increased from 0.7% in 1999 to 2.4% in 2013.ConclusionsThere was a substantial increase in lumbar spine surgery in Norway from 1999 to 2013, similar to trends in other Western world countries. The rise in lumbar surgery among elderly people represents a significant workload and challenge for health services, given our aging population.

Aims The aims of this study were to determine the rates of surgical complications, reoperations, and readmissions following herniated lumbar disc surgery, and to investigate the impact of sociodemographic factors and comorbidity on the rate of such unfavourable events. Patients and Methods This was a longitudinal observation study. Data from herniated lumbar disc operations were retrieved from a large medical database using a combination of procedure and diagnosis codes from all public hospitals in Norway from 1999 to 2013. The impact of age, gender, geographical affiliation, education, civil status, income, and comorbidity on unfavourable events were analyzed by logistic regression. Results Of 34 639 operations, 2.7% (95% confidence interval (CI) 2.6 to 2.9) had a surgical complication, 2.1% (95% CI 2.0 to 2.3) had repeat surgery within 90 days, 2.4% (95% CI 2.2 to 2.5) had a non-surgical readmission within 90 days, and 6.7% (95% CI 6.4 to 6.9) experienced at least one of these unfavourable events. Unfavourable events were found to be associated with advanced age and comorbidity. Conclusion The results suggest that surgical complications are less frequent than previously suggested. There are limited associations between sociodemographic patient characteristics and unfavourable events. Cite this article: Bone Joint J 2019;101-B:470–477.

Objective To assess the efficacy of three months of antibiotic treatment compared with placebo in patients with chronic low back pain, previous disc herniation, and vertebral endplate changes (Modic changes). Design Double blind, parallel group, placebo controlled, multicentre trial. Setting Hospital outpatient clinics at six hospitals in Norway. Participants 180 patients with chronic low back pain, previous disc herniation, and type 1 (n=118) or type 2 (n=62) Modic changes enrolled from June 2015 to September 2017. Interventions Patients were randomised to three months of oral treatment with either 750 mg amoxicillin or placebo three times daily. The allocation sequence was concealed by using a computer generated number on the prescription. Main outcome measures The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (range 0-24) at one year follow-up in the intention to treat population. The minimal clinically important between group difference in mean RMDQ score was predefined as 4. Results In the primary analysis of the total cohort at one year, the difference in the mean RMDQ score between the amoxicillin group and the placebo group was −1.6 (95% confidence interval −3.1 to 0.0, P=0.04). In the secondary analysis, the difference in the mean RMDQ score between the groups was −2.3 (−4.2 to−0.4, P=0.02) for patients with type 1 Modic changes and −0.1 (−2.7 to 2.6, P=0.95) for patients with type 2 Modic changes. Fifty patients (56%) in the amoxicillin group experienced at least one drug related adverse event compared with 31 (34%) in the placebo group. Conclusions In this study on patients with chronic low back pain and Modic changes at the level of a previous disc herniation, three months of treatment with amoxicillin did not provide a clinically important benefit compared with placebo. Secondary analyses and sensitivity analyses supported this finding. Therefore, our results do not support the use of antibiotic treatment for chronic low back pain and Modic changes. Trial registration ClinicalTrials.gov NCT02323412 .

AJ Haugen,1 L Grøvle,1 JI Brox,2 B Natvig,3 M Grotle4 1Department of Rheumatology, Østfold Hospital Trust, Grålum, 2Department of Physical Medicine and Rehabilitation, Division for Neuroscience, Oslo University Hospital, 3Department of General Practice, Institute of Health and Society, University of Oslo, 4FORMI (Communication Unit for Musculoskeletal Disorders), Division of Neuroscience, Oslo University Hospital, Oslo, Norway Objectives: The purpose of this study was to explore the associations between pain-related fear, pain disability, and self-perceived recovery among patients with sciatica and disk herniation followed up for 2years.Patients and methods: Pain-related fear was measured by the Tampa Scale for Kinesiophobia (TSK) and the Fear-Avoidance Beliefs Questionnaire-Physical Activity (FABQ-PA) subscale. Disability was measured by the Maine–Seattle Back Questionnaire. At 2years, patients reported their sciatica/back problem on a global change scale ranging from completely gone to much worse. No specific interventions regarding pain-related fear were provided.Results: Complete data were obtained for 372 patients. During follow-up, most patients improved. In those who at 2years were fully recovered (n=66), pain-related fear decreased substantially. In those who did not improve (n=50), pain-related fear remained high. Baseline levels of pain-related fear did not differ significantly between those who were fully recovered and the rest of the cohort. In the total cohort, the correlation coefficients between the 0–2-year change in disability and the changes in the TSK and the FABQ-PA were 0.33 and 0.38, respectively. In the adjusted regression models, the 0–2-year change in pain-related disability explained 15% of the variance in the change in both questionnaires.Conclusion: Pain-related fear decreased substantially in patients who recovered from sciatica and remained high in those who did not improve. Generally, the TSK and the FABQ-PA yielded similar results. To our knowledge, this is the first study that has assessed pain-related fear in patients who recover from sciatica. Keywords: kinesiophobia, fear-avoidance, recovery

Retrospective administrative database study.To assess temporal and regional trends, and length of hospital stay, in lumbar spinal stenosis (LSS) surgery in Norwegian public hospitals from 1999 to 2013.Studies from several countries have reported increasing rates of LSS surgery over the last decades. No such data have been presented from Norway.A database consisting of discharges from all Norwegian public hospitals was established. Inclusion criteria were discharges including a surgical procedure of lumbar spinal decompression and/or fusion in combination with an International Statistical Classification of Diseases and Related Health Problems, 10th Revision diagnosis of Spinal Stenosis (M48.0) or Other Spondylosis with Radiculopathy (M47.2), and a patient age of 18 years or older. Discharges with diagnoses indicating deformity, that is, spondylolisthesis or scoliosis were not included.During the 15-year period, 19,543 discharges were identified. The annual rate of decompressions increased from 10.7 to 36.2 and fusions increased from 2.5 to 4.4 per 100,000 people of the general Norwegian population. The proportion of fusion surgery decreased from 19.3% to 10.9%. Among individuals older than 65 years, the annual rate of surgery per 10,000, including both decompressions and fusions, more than quadrupled from 40.2 to 170.3. The regional variation was modest, differing with a factor of 1.4 between the region with the highest and the lowest surgical rates. The mean length of hospital stay decreased from 11.0 (standard deviation 8.0) days in 1999 to 5.0 (4.6) days in 2013, but patients who received fusion surgery stayed on average 3.6 days longer than those who received decompression only.The rate of LSS surgery more than tripled in Norway from 1999 to 2013. The mean length of hospital stay was reduced from 11 to 5 days.N/A.

Objectives To investigate the longitudinal validity of patients' ratings of global perceived change (GPC) and to assess the implications of using the GPC as the anchor to determine the minimal important change (MIC). Study Design and Setting Secondary analysis of data from a multicenter study including 380 patients with disc-related sciatica with follow-ups at 3, 6, 12, and 24 months. The GPC scale ranged from much worse to completely gone. Five patient-reported outcome measures were used. An MIC was defined as the mean change score in the actual outcome measure for patients reporting being better. The influence of patients' current state and baseline scores on the GPC was analyzed by multivariate linear regression. Differences in the magnitude of the MIC between the 3- and 24-month recall periods were analyzed by hierarchical linear models. Results Across all recall periods and outcome measures, the GPC was strongly influenced by the patient's state at the time of asking. In four of five outcome measures, the magnitude of the MIC increased when recall increased from 3 to 24 months. Conclusion Caution is needed when using the GPC to determine the MIC of patient-reported outcome measures in patients with chronic conditions.

Objectives The occurrence of polymyositis (PM) and dermatomyositis (DM) in the general population is largely unknown and unbiased data on clinical and laboratory features in PM/DM are missing. Here, we aim to identify and characterise every PM/DM patient living in southeast Norway (denominator population 2.64 million), 2003–2012. Method Due to the structure of the Norwegian health system, all patients with PM/DM are followed at public hospitals. Hence, all public hospital databases in southeast Norway were screened for patients having ICD-10 codes compatible with myositis. Manual chart review was then performed to identify all cases meeting the Peter & Bohan and/or Targoff classification criteria for PM/DM. Results The ICD-10 search identified 3160 potential myositis patients, but only 208/3160 patients met the Peter & Bohan criteria and 230 the Targoff criteria (100 PM, 130 DM). With 56 deaths during the observation period, point prevalence of PM/DM was calculated to 8.7/100 000. Estimated annual incidences ranged from 6 to 10 /1 000 000, with peak incidences at 50–59 (DM) and 60–69 years (PM). Myositis specific antibodies (Jo-1, PL-7, PL-12, signal recognition particle (SRP) and Mi-2) were present in 53% (109/204), while 137/163 (87%) had pathological muscle MRI. Frequent clinical features included myalgia (75%), arthritis (41%) dyspnoea (62%) and dysphagia (58%). Positive anti-Jo-1, present in 39% of DM and 22% of PM cases, was associated with dyspnoea, arthritis and mechanic hands. Conclusions Our data indicate that the population prevalence of PM/DM in Caucasians is quite low, but underscores the complexity and severity of the disorders.

To explore how patients with sciatica rate the 'bothersomeness' of paresthesia (tingling and numbness) and weakness as compared with leg pain during 2 years of follow-up.Observational cohort study including 380 patients with sciatica and lumbar disc herniation referred to secondary care. Using the Sciatica Bothersomeness Index paresthesia, weakness and leg pain were rated on a scale from 0 to 6. A symptom score of 4-6 was defined as bothersome.Along with leg pain, the bothersomeness of paresthesia and weakness both improved during follow-up. Those who received surgery (n = 121) reported larger improvements in both symptoms than did those who were treated without surgery. At 2 years, 18.2% of the patients reported bothersome paresthesia, 16.6% reported bothersome leg pain, and 11.5% reported bothersome weakness. Among patients with no or little leg pain, 6.7% reported bothersome paresthesia and 5.1% bothersome weakness.During 2 years of follow-up, patients considered paresthesia more bothersome than weakness. At 2 years, the percentage of patients who reported bothersome paresthesia was similar to the percentage who reported bothersome leg pain. Based on patients' self-report, paresthesia and weakness are relevant aspects of disc-related sciatica.

Objective To investigate the agreement between self-report and a public registry regarding the occurrence and duration of sickness absence (SA) in patients with sciatica. Study Design and Setting Observational 2-year longitudinal study including 227 patients. Self-report SA data were obtained by postal questionnaires covering recall periods of 3, 6, and 12 months and compared with data from the Norwegian National Sickness Benefit Register. Results The percent agreement on the occurrence of SA between self-report and registry was above 85% for all three recall periods. The patients overestimated the duration of their SA by 2.4 (95% confidence interval, 1.1–3.7) weeks for the 3-month recall period. The 95% limits of agreement were generally wide, varying from −12.5 to 17.3 weeks for the 3-month recall period to −38.8 to 37.2 weeks for the 12-month period. For the 3-, 6-, and 12-month recall periods, 48.1%, 29.8%, and 27.3% of the patients reported an SA duration that differed by ≤1 week from that recorded in the registry. Conclusion Mainly because of low precision, the agreement on the duration of SA was poor for all three recall periods. The agreement between self-report and registry regarding the occurrence of SA was good.

Chronic nonspecific low back pain is accompanied by high rates of comorbid mental and physical conditions. The aims of this study were to investigate if patients with specific back pain, that is, sciatica caused by lumbar herniation, report higher rates of subjective health complaints (SHCs) than the general population and if there is an association between change in sciatica symptoms and change in SHCs over a 12-month period.A multicenter cohort study of 466 sciatica patients was conducted with follow-up at 3 months and 1 year. Comorbid SHCs were measured by 27 items of the SHC inventory. Odds ratios (ORs) for each SHC were calculated with comparison to a general population sample (n=928) by logistic regression. The SHC number was calculated by summing all complaints present.At baseline, the ORs for reporting SHCs for the sciatica patients were significantly elevated in 15 of the 27 items with a mean (S.D.) SHC number of 7.5 (4.4), compared to 5.2 (4.4) in the general population (P.01). Among those who during the 1-year follow-up period fully recovered from their sciatica, the SHC number was reduced to normal levels. Among those with persisting or worsening sciatica, the number increased to a level almost double that of the general population.Compared to the general population, the prevalence of subjective health complaints in sciatica is increased. During follow-up, the number of health complaints increased in patients with persisting or worsening sciatica.

The objective of the study was to investigate how patients with sciatica due to disc herniation rate the bothersomeness of paresthesia and weakness as compared to leg pain, and how these symptoms are associated with socio-demographic and clinical characteristics. A cross-sectional study was conducted on 411 patients with clinical signs of radiculopathy. Items from the Sciatica Bothersomeness Index (0 = none to 6 = extremely) were used to establish values for paresthesia, weakness and leg pain. Associations with socio-demographic and clinical variables were analyzed by multiple linear regression. Mean scores (SD) were 4.5 (1.5) for leg pain, 3.4 (1.8) for paresthesia and 2.6 (2.0) for weakness. Women reported higher levels of bothersomeness for all three symptoms with mean scores approximately 10% higher than men. In the multivariate models, more severe symptoms were associated with lower physical function and higher emotional distress. Muscular paresis explained 19% of the variability in self-reported weakness, sensory findings explained 10% of the variability in paresthesia, and straight leg raising test explained 9% of the variability in leg pain. In addition to leg pain, paresthesia and weakness should be assessed when measuring symptom severity in sciatica.

Study design Cross-sectional and prospective study of patients with sciatica and disc herniation. Objective To describe the process of translation of the Norwegian versions of the Maine Seattle Back Questionnaire (MSBQ), the Sciatica Bothersomeness Index (SBI) and the Sciatica Frequency Index (SFI), and to test the reliability, construct validity and responsiveness of these Norwegian versions. Summary of background data The instruments have been validated in English only. Methods Reliability was assessed by internal consistency (Cronbach alpha), test-retest reliability (ICC) and measurement error (MDC and Bland and Altman's limits of agreement). Construct validity was assessed by comparing the 3 measures with subscales of SF-36, ratings of back and leg pain, and clinical findings. Responsiveness was assessed by standardized response means and Receiver Operating Characteristic curve analyses. Results Four hundred sixty six patients were included in the study, of whom 87 participated in the test-retest study. Completion time for the MSBQ was 1-2 minutes and 30 seconds for the SBI and the SFI, respectively. ICCs varied between 0.86 and 0.90. Cronbach alpha was 0.74, 0.70, and 0.65 for the MSBQ, SBI, and SFI, respectively. The measurement errors constituted 26% of the total MSBQ score range, 22% of the SBI and 27% of the SFI score range. Compared to the MSBQ the 2 Sciatica Indexes discriminated better between patients with normal versus abnormal clinical findings, but correlated less strongly with pain and physical functioning. Responsiveness was assessed by 2 external criteria at 3 months, a global change score (improved vs. unchanged) and surgical treatment status (operated vs. nonoperated). All standardized response means were >or=1.3 and all AUCs >or=0.75. Differences between the 3 measures were generally small. Conclusion The Norwegian versions of the MSBQ and the Sciatica Frequency and Bothersomeness Indexes were rapidly administered, with acceptable internal consistency, test-retest reliability, measurement error, construct validity and responsiveness.

Background Earlier observations show that development of persistent pain may be associated with the genetic variability in the gene encoding for the μ-opioid receptor 1, the OPRM1 A118G (rs1799971). The aim of this study was to investigate the association between OPRM1 genotype and subjective health complaints in patients with radicular pain and disc herniation. Methods A prospective, 1-year observational study was conducted at a hospital back clinic, including 118 Caucasian patients with lumbar radicular pain and MRI confirmed disc herniation. Single nucleotide polymorphism genotyping regarding the OPRM1 A118G was performed. The data of individuals with AA versus AG or GG were analysed separately by linear mixed models. The Subjective Health Complaints Inventory (0-81) including 27 common complaints experienced the previous month on a scale from not at all (0) to severe (3) was used as outcome. Pain, prior duration of leg pain, age, smoking status, and lumbar disc surgery were considered as covariates. Results In total 23 of 118 patients were carriers of the OPRM1 G-allele. All patients except female carriers of the G-allele reported a decrease in pain from baseline to 1 year. Female carriers of the G-allele reported significantly higher subjective health complaints score during the study time span than male carriers of the G-allele when controlling for pain and pain duration. Conclusion The present data indicate that, when controlling for pain intensity and duration, subjective health complaints are associated with a sex - OPRM1 A118G polymorphism interaction in patients with radicular pain.

Background The treat to target (T2T) strategy has provided good results in clinical trials and is part of current management recommendations, but real life data are still needed to support the implementation of T2T in clinical practice. Objectives To investigate 2-year outcomes (DAS28 and EQ-5D) in early RA before and after implementation of the T2T monitoring and treatment strategy. Methods Pts in the Norwegian Very Early Arthritis Cohort (NOR-VEAC) were included from 2010 through 2015 and treated according to T2T with visits at baseline, 3, 6, 9, 12 months and then every 6 months plus monthly visits until DAS28 Results The current analyses included 252 pts from NOR-VEAC (mean (SD) age 54 (14) yrs, 65% females, 73% seropos, duration of joint swelling median (25,75 perc) 97 (57,168) days) and 586 pts from NOR-DMARD (mean (SD) age 55 (13) yrs, 67% females, 74% seropos, median (25,75 perc) 4 (0,67) days since diagnosis). 2-yr follow-up data were available in 56%/67% of pts in NOR-VEAC/NOR-DMARD. Methotrexate monotherapy was the dominant initial DMARD treatment in both groups (93% in NOR-VEAC vs 87% in NOR-DMARD). Proportions of pts achieving remission (DAS28 Conclusions Pts treated according to the T2T strategy achieved lower DAS28 scores and higher (better) EQ-5D scores during follow-up despite similar baseline values. The differences in DMARD use between cohorts were relatively small, however there is a trend towards more use of biologic DMARD in the T2T cohort. Disclosure of Interest G. H. Brinkmann: None declared, E. Norli: None declared, T. Kvien Grant/research support from: AbbVie, BMS, MSD, Pfizer, Roche and UCB, Consultant for: AbbVie, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Orion Pharma, Pfizer, Roche, Sandoz, UCB, Speakers bureau: AbbVie, BMS, Boehringer Ingelheim, Celgene, Celltrion, Eli Lilly, Hospira, Merck-Serono, MSD, Novartis, Orion Pharma, Pfizer, Roche, Sandoz,UCB, A. Haugen: None declared, L. Grovle: None declared, H. Nygaard: None declared, D. Soldal: None declared, A. Wierod: None declared, H. Gulseth: None declared, M. Mjaavatten: None declared, E. Lie Consultant for: AbbVie, Bristol-Myers Squibb, Hospira, Pfizer, UCB, Speakers bureau: AbbVie, Bristol-Myers Squibb

Background Few studies have investigated prognostic factors for patients with sciatica, especially for patients treated without surgery. The aim of this study was to identify factors associated with non-success after 1 and 2 years of follow-up and to test the prognostic value of surgical treatment for sciatica. Methods The study was a prospective multicentre observational study including 466 patients with sciatica and lumbar disc herniation. Potential prognostic factors were sociodemographic characteristics, back pain history, kinesiophobia, emotional distress, pain, comorbidity and clinical examination findings. Study participation did not alter treatment considerations for the patients in the clinics. Patients reported on the questionnaires if surgery of the disc herniation had been performed. Uni- and multivariate logistic regression analyses were used to evaluate factors associated with non-success, defined as Maine–Seattle Back Questionnaire score of ≥5 (0–12) (primary outcome) and Sciatica Bothersomeness Index ≥7 (0–24) (secondary outcome). Results Rates of non-success were at 1 and 2 years 44% and 39% for the main outcome and 47% and 42% for the secondary outcome. Approximately 1/3 of the patients were treated surgically. For the main outcome variable, in the final multivariate model non-success at 1 year was significantly associated with being male (OR 1.70 [95% CI; 1.06 − 2.73]), smoker (2.06 [1.31 − 3.25]), more back pain (1.0 [1.01 − 1.02]), more comorbid subjective health complaints (1.09 [1.03 − 1.15]), reduced tendon reflex (1.62 [1.03 − 2.56]), and not treated surgically (2.97 [1.75 − 5.04]). Further, factors significantly associated with non-success at 2 years were duration of back problems >; 1 year (1.92 [1.11 − 3.32]), duration of sciatica >; 3 months (2.30 [1.40 − 3.80]), more comorbid subjective health complaints (1.10 [1.03 − 1.17]) and kinesiophobia (1.04 [1.00 − 1.08]). For the secondary outcome variable, in the final multivariate model, more comorbid subjective health complaints, more back pain, muscular weakness at clinical examination, and not treated surgically, were independent prognostic factors for non-success at both 1 and 2 years. Conclusions The results indicate that the prognosis for sciatica referred to secondary care is not that good and only slightly better after surgery and that comorbidity should be assessed in patients with sciatica. This calls for a broader assessment of patients with sciatica than the traditional clinical assessment in which mainly the physical symptoms and signs are investigated.

Background context Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation. Purpose To identify the prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care. Study design/setting Multicenter prospective cohort study including 466 patients. Administrative data from the National Sickness Benefit Register were accessed for 227 patients. Patient sample Two samples were used. Sample A comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave or were undergoing rehabilitation because of back pain/sciatica. Sample B comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica. Outcome measures In Sample A, the outcome was self-reported return to full-time work at the 2-year follow-up. In Sample B, the outcome was time to first sustained RTW, defined as the first period of more than 60 days without receiving benefits from the register. Methods Significant baseline predictors of self-reported RTW at 2 years (Analysis A) were identified by multivariate logistic regression. Significant predictors of time to sustained RTW (Analysis B) were identified by multivariate Cox proportional hazard modeling. Both analyses included adjustment for age and sex. To assess the effect of surgery on the probability of RTW, analyses similar to A and B were performed, including the variable surgery (yes/no). Results One-fourth of the patients were still out of work at the 2-year follow-up. In Sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear-avoidance work, and a negative straight-leg–raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In Sample B (n=125), history of sciatica, duration of the current sciatica episode more than 3 months, greater sciatica bothersomeness, fear-avoidance work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was significantly negatively associated with time to sustained RTW both in univariate (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.39, 0.93; p=.02) and in multivariate (HR 0.49; 95% CI 0.31, 0.79; p=.003) analyses. Conclusions The baseline factors associated with RTW identified in multivariate analysis were age, general health, history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear-avoidance work, back pain, and the straight-leg–raising test result. Surgical treatment was associated with slower RTW, but surgical patients were more severely affected than patients treated without surgery; so, this finding should be interpreted with caution.

STUDY DESIGN Translation, cross-cultural adaptation, and validation of a self-report questionnaire. OBJECTIVE To perform a translation and cross-cultural adaptation of the Tampa scale for kinesiophobia (TSK) and to investigate its test-retest reliability, construct validity, and responsiveness among Norwegian-speaking patients with sciatica due to disc herniation. SUMMARY OF BACKGROUND DATA The TSK is a self-report questionnaire developed to assess kinesiophobia, or fear of movement and/or (re)injury. To date, the psychometric properties of the TSK have not been demonstrated in patients with sciatica. METHODS The TSK was translated and back-translated according to recent guidelines for cross-cultural adaptation of self-report measures. A principal components analysis and an evaluation of floor and ceiling effects were conducted. The TSK was tested for test-retest reliability, repeatability, internal consistency, and construct validity. Responsiveness was measured as standardized response means using a global change scale after 3 months as the external criteria. RESULTS In total, 466 patients with sciatica due to disc herniation were included. The TSK was easily comprehended. The principal components analysis yielded 3 factors. Component 1 showed a floor effect in which 152 (33.3%) of the patients achieved the lowest possible score. Repeatability according to Bland & Altman was 8, the coefficient of variance for paired measurements was 11%, and weighted kappa values for each item were moderate to substantial. Internal consistency by Cronbach's alpha was 0.81. Correlations with the Fear Avoidance Beliefs Questionnaire (FABQ), FABQ/work, and FABQ/physical activity were 0.50, 0.38, and 0.51, respectively. Responsiveness was low to moderate. CONCLUSION The Norwegian version of the TSK was easily comprehended and demonstrated satisfactory validity and reliability for the assessment of fear of movement and/or (re)injury in patients with sciatica due to disc herniation. However, responsiveness was low to moderate.

Background Undifferentiated arthritis (UA) is defined as cases of inflammatory arthritis where no definitive diagnosis can be made, and that may evolve into a chronic inflammatory disease over time or result in persistent drug-free remission. Objectives In this study we investigated the 2-year disease course in patients with poly-, oligo- and monoarticular UA, with the main outcomes being 1) fulfillment of the 2010 ACR/EULAR RA classification criteria, 2) absence of clinical synovitis without use of DMARDs and 3) final clinical diagnosis. Methods Patients (18-75 years old) with ≥1 swollen joint of Results Among the 495 patients who were denoted UA, 60 (12.1%) patients had polyarthritis (PA), 179 (36.2%) oligoarthritis (OLA) and 256 (51.7%) monoarthritis (MA) at baseline. Mean (SD) age was 46.6 (14.6) yrs, 54.1% were females and median (25, 75 perc.) duration of joint swelling was 29 (10, 62) days. Only 34 (6.9%) of the 495 UA patients were classified as RA during follow-up, including 8.9% of those presenting as OLA and 13.3% of those presenting as PA. Conversely, among patients later classified as RA, 47.1% were OLA patients and 23.5% PA patients at inclusion. 50.0% of the OLA patients who later fulfilled the RA criteria were seropositive, while none of the PA patients were. The most frequently affected joints in the OLA patients fulfilling the RA criteria were PIP (31.3%), MCP (25.0%), knees (31.3%) and wrists (31.3%). Only 86 of 495 patients used DMARDs during follow-up (38.3% of all PA patients, 20.1% OA patients and 10.4% of MA patients). 41.7%, 63.8% and 76.6% of those presenting as PA, OLA and MA, respectively, achieved absence of clinical synovitis at final follow-up visit without use of DMARDs. The most frequent final clinical diagnosis in PA, OLA and MA patients was UA (40.0%, 50.1% and 68.3%, respectively). Figure 1 shows the distribution of clinical diagnoses at last visit. Conclusions Less than 1/5 of all the UA patients started DMARDs, and only 6.9% of the UA patients were classified as RA during follow-up, including 9% of those presenting as OLA and 13% of those presenting as PA. Nearly half of patients later classified as RA were patients with OLA at inclusion, however, 64% of OLA cases resolved without ever using DMARDs. The proportion with a final clinical diagnosis of UA was high irrespective of poly-, oligo- or monoarticular presentation. Disclosure of Interest None declared

Background Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation. Objectives To identify prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care. Methods The setting was a multicenter prospective cohort study including 466 patients. Study participation did not involve any specific type of intervention. In patients with severe symptoms, surgery was performed at the discretion of each center. Administrative data from the National Sickness Benefit Register were accessed for 227 patients. Two patient samples were used. Sample (A) comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave, or were undergoing rehabilitation because of back pain/sciatica. Sample (B) comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica. In sample (A), the outcome was self-reported return to full-time work at the 2-year follow-up. In sample (B), the outcome was time to first sustained RTW, defined as the first period of >60 days without receiving benefits from the register. Analyses were performed by multivariate logistic regression and Cox proportional hazard modeling. Results One-fourth of the patients were still out of work at the 2-year follow-up. In sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear avoidance–work, and a negative straight-leg-raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In sample B (n=125), a previous history of sciatica, duration of the current sciatica episode >3 months, and greater sciatica bothersomeness, fear avoidance–work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was negatively associated with time to sustained RTW both in univariate (hazard ratio,HR 0.60; 95% confidence interval (CI) 0.39, 0.93; p=0.02) and in multivariate analysis (HR 0.49; 95% CI 0.31, 0.79; p=0.003). Conclusions The baseline factors associated with RTW identified in multivariate analysis were age, general health, previous history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear avoidance–work, back pain, and the straight-leg-raising test result. Surgical treatment was associated with slower RTW. Disclosure of Interest None Declared