Correction: Clinical improvement after surgery for degenerative cervical myelopathy; A comparison of Patient-Reported Outcome Measures during 12-month follow-up.

[This corrects the article DOI: 10.1371/journal.pone.0264954.].

Machine Learning Models for Predicting Disability and Pain Following Lumbar Disc Herniation Surgery.

Importance: Lumber disc herniation surgery can reduce pain and disability. However, a sizable minority of individuals experience minimal benefit, necessitating the development of accurate prediction models. Objective: To develop and validate prediction models for disability and pain 12 months after lumbar disc herniation surgery. Design, Setting, and Participants: A prospective, multicenter, registry-based prognostic study was conducted on a cohort of individuals undergoing lumbar disc herniation surgery from January 1, 2007, to May 31, 2021. Patients in the Norwegian Registry for Spine Surgery from all public and private hospitals in Norway performing spine surgery were included. Data analysis was performed from January to June 2023. Exposures: Microdiscectomy or open discectomy. Main Outcomes and Measures: Treatment success at 12 months, defined as improvement in Oswestry Disability Index (ODI) of 22 points or more; Numeric Rating Scale (NRS) back pain improvement of 2 or more points, and NRS leg pain improvement of 4 or more points. Machine learning models were trained for model development and internal-external cross-validation applied over geographic regions to validate the models. Model performance was assessed through discrimination (C statistic) and calibration (slope and intercept). Results: Analysis included 22 707 surgical cases (21 161 patients) (ODI model) (mean [SD] age, 47.0 [14.0] years; 12 952 [57.0%] males). Treatment nonsuccess was experienced by 33% (ODI), 27% (NRS back pain), and 31% (NRS leg pain) of the patients. In internal-external cross-validation, the selected machine learning models showed consistent discrimination and calibration across all 5 regions. The C statistic ranged from 0.81 to 0.84 (pooled random-effects meta-analysis estimate, 0.82; 95% CI, 0.81-0.84) for the ODI model. Calibration slopes (point estimates, 0.94-1.03; pooled estimate, 0.99; 95% CI, 0.93-1.06) and calibration intercepts (point estimates, -0.05 to 0.11; pooled estimate, 0.01; 95% CI, -0.07 to 0.10) were also consistent across regions. For NRS back pain, the C statistic ranged from 0.75 to 0.80 (pooled estimate, 0.77; 95% CI, 0.75-0.79); for NRS leg pain, the C statistic ranged from 0.74 to 0.77 (pooled estimate, 0.75; 95% CI, 0.74-0.76). Only minor heterogeneity was found in calibration slopes and intercepts. Conclusion: The findings of this study suggest that the models developed can inform patients and clinicians about individual prognosis and aid in surgical decision-making.

Longitudinal Relationship Between Reduced Modic Change Edema and Disability and Pain in Patients With Chronic Low Back Pain.

STUDY DESIGN: Secondary analyses of a randomized trial [Antibiotics In Modic changes (MCs) study]. OBJECTIVE: To assess whether or not reduced MC edema over time is related to reduced disability and pain in patients with chronic low back pain (LBP). SUMMARY OF BACKGROUND DATA: It is not clear whether or not reduced MC edema implies improved clinical outcomes. PATIENTS AND METHODS: Linear regression was conducted separately in 2 subgroups with MC edema at baseline on short tau inversion recovery (STIR) or T1/T2-weighted magnetic resonance imaging, respectively. Independent variable: reduced edema (yes/no) at 1 year on STIR or T1/T2-series, respectively. Dependent variable: 1-year score on the Roland-Morris Disability Questionnaire (RMDQ), Oswestry Disability Index (ODI), or 0 to 10 numeric rating scale for LBP intensity, adjusted for the baseline score, age, smoking, body mass index, physical workload, and baseline edema on STIR (STIR analysis only). Post hoc, we, in addition, adjusted all analyses for baseline edema on STIR, treatment group (amoxicillin/placebo), and prior disc surgery-or for disc degeneration. RESULTS: Among patients with MC edema on STIR at baseline (n = 162), reduced edema on STIR was not significantly related to the RMDQ ( B : -1.0, 95% CI: -2.8, 0.8; P = 0.27), ODI ( B :-1.4, 95% CI: -5.4, 2.6; P = 0.50), or LBP intensity scores ( B : -0.05, 95% CI: -0.8, 0.7; P = 0.90) after 1 year. Among patients with MC edema on T1/T2-series at baseline (n = 116), reduced edema on T1/T2 ( i.e ., reduced volume of the type 1 part of MCs) was not significantly related to RMDQ ( B: -1.7, 95% CI: -3.8, 0.3; P = 0.10) or ODI score ( B : -2.3, 95% CI: -7.1, 2.5; P = 0.34) but was significantly related to LBP intensity at 1 year ( B : -0.9, 95% CI: -1.8, -0.04; P = 0.04; correlation coefficient: 0.24). The post hoc analyses supported these results. CONCLUSION: Reduced MC edema over 1 year was not significantly associated with pain-related disability but was (on T1/T2-series) significantly but weakly related to reduced LBP intensity. LEVEL OF EVIDENCE: Level 3.

Effect of Godelieve Denys-Struyf (GDS) muscle and articulation chain treatment on clinical variables of patients with chronic low back pain and lumbar disc degeneration: a pilot feasibility randomized controlled trial.

BACKGROUND: Patients with chronic low back pain (LBP) and lumbar disc degeneration are recommended to try out nonsurgical treatment options before surgery. There is need for good nonsurgical alternatives that can be adapted to the patient's needs and level of function. The aim of this pilot trial was to test study feasibility of a future full randomized controlled trial (RCT) evaluating the feasibility and benefit of the physiotherapy-based Godelieve Denys-Struyf (GDS) muscle and articulation chain treatment for patients with chronic LBP and lumbar disc degeneration referred to surgical assessment in a hospital outpatient clinic. METHODS: This study is a single-center, two-arm, single-blinded, pilot RCT conducted in a regional hospital in Norway. Patients of age 35-75 years with chronic (> 3 months) LBP and degenerative lumbar disc(s) verified by imaging were included. They filled in a baseline questionnaire prior to randomization, including the Oswestry Disability Index (ODI), numerical rating scale for pain in back and pain in leg, and the EuroQoL 5L. Patients in the control group were free to use treatment as usual. Patients in the intervention group received 8 sessions over a period of 10 to 14 weeks of GDS muscle and articulation chain treatment. RESULTS: The recruitment rate was slow, approximately 3/4th of the referred patients met the inclusion criteria, but majority of eligible participants (94%) were willing to participate. A total of 30 patients were randomized into the two groups. The randomization led to skewed distribution of radiating leg pain in the two groups. All participants except one (97%) completed 4 months follow-up. No serious adverse events attributable to the trial treatments were reported. The Oswestry Disability Index (ODI) and leg pain intensity scale were both suitable as primary outcomes in a full trial. The mean change in the ODI score was 8.7 (SD 16.1) points in the GDS arm, whereas there was a minor deterioration in the ODI scores of -3.7 (7.5) points in the control arm. A sample size calculation based on the ODI scores resulted in a number needed to treat of 3. CONCLUSIONS: A future full RCT is feasible and would provide evidence about the effectiveness of a GDS treatment for patients with chronic LBP and lumbar disc degeneration. TRIAL REGISTRATION: ClinicalTrials.gov ID: 910193.

A novel method for the translation and cross-cultural adaptation of health-related quality of life patient-reported outcome measurements.

BACKGROUND: This paper presents a novel methodology for translation and cross-cultural adaptation of health-related quality-of-life patient-reported outcome measures, incorporating the Delphi method. Specifically, we describe the process of translating the Pelvic Floor Distress Inventory-20 and Pelvic Floor Impact Questionnaire-7 from English to Norwegian using this method. METHODS: The multistep translation method combined the European Organization for Research and Treatment of Cancer Quality of Life guidelines, an Expert Panel review, and the Delphi method. It comprised two independent forward- and back-translations. While the bilingual pelvic floor Expert Panel ensured rigorous cross-checking and effective cross-cultural adaptation, the addition of the Delphi method (comprising the attributes of anonymity, controlled feedback, and statistical group response) further established consensus on translated items. OUTCOMES: The application of the Delphi method in the Expert Panel phase proved adequate in producing comprehensible intermediate Norwegian versions ready for pilot testing. The Expert Panel reviewed the comments made by patients completing the instruments and offered advice to allow final translated versions to be produced and tested for measurement properties. This iterative approach, internal logic, and anonymity between rounds improved the evaluations that the panel members provided, which in turn enhanced the final translated Patient Reported Outcome Measures (PROMs). CONCLUSIONS: To our knowledge, this work represents the first demonstration of the application of an Expert Panel review incorporating a Delphi method to assess health-related quality-of-life instruments. The controlled feedback approach, iterative nature, internal logic, and anonymity of the Delphi consensus method appeared to ensure a good cross-cultural adaptation of these PROMs.

Anterior surgical treatment for cervical degenerative radiculopathy: a prediction model for non-success.

PURPOSE: By using data from the Norwegian Registry for Spine Surgery, we wanted to develop and validate prediction models for non-success in patients operated with anterior surgical techniques for cervical degenerative radiculopathy (CDR). METHODS: This is a multicentre longitudinal study of 2022 patients undergoing CDR surgery and followed for 12 months to find prognostic models for non-success in neck disability and arm pain using multivariable logistic regression analysis. Model performance was evaluated by area under the receiver operating characteristic curve (AUC) and a calibration test. Internal validation by bootstrapping re-sampling with 1000 repetitions was applied to correct for over-optimism. The clinical usefulness of the neck disability model was explored by developing a risk matrix for individual case examples. RESULTS: Thirty-eight percent of patients experienced non-success in neck disability and 35% in arm pain. Loss to follow-up was 35% for both groups. Predictors for non-success in neck disability were high physical demands in work, low level of education, pending litigation, previous neck surgery, long duration of arm pain, medium-to-high baseline disability score and presence of anxiety/depression. AUC was 0.78 (95% CI, 0.75, 0.82). For the arm pain model, all predictors for non-success in neck disability, except for anxiety/depression, were found to be significant in addition to foreign mother tongue, smoking and medium-to-high baseline arm pain. AUC was 0.68 (95% CI, 0.64, 0.72). CONCLUSION: The neck disability model showed high discriminative performance, whereas the arm pain model was shown to be acceptable. Based upon the models, individualized risk estimates can be made and applied in shared decision-making with patients referred for surgical assessment.

Amoxicillin Did Not Reduce Modic Change Edema in Patients With Chronic Low Back Pain: Subgroup Analyses of a Randomised Trial (the AIM Study).

STUDY DESIGN: Exploratory subgroup analyses of a randomised trial [Antibiotics in Modic changes (AIM) study]. OBJECTIVE: The aim was to assess the effect of amoxicillin versus placebo in reducing Modic change (MC) edema in patients with chronic low back pain. SUMMARY OF BACKGROUND DATA: The AIM study showed a small, clinically insignificant effect of amoxicillin on pain-related disability in patients with chronic low back pain and MC type 1 (edema type) on magnetic resonance imaging (MRI). MATERIALS AND METHODS: A total of 180 patients were randomised to receive 100 days of amoxicillin or placebo. MC edema was assessed on MRI at baseline and one-year follow-up. Per-protocol analyses were conducted in subgroups with MC edema on short tau inversion recovery (STIR) or T1/T2-weighted MRI at baseline. MC edema reductions (yes/no) in STIR and T1/T2 series were analyzed separately. The effect of amoxicillin in reducing MC edema was analyzed using logistic regression adjusted for prior disk surgery. To assess the effect of amoxicillin versus placebo within the group with the most abundant MC edema 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 edema reduction). RESULTS: Compared to placebo, amoxicillin did not reduce MC edema on STIR (volume/intensity) in the total sample with edema on STIR at baseline (odds ratio 1.0, 95% CI: 0.5, 2.0; n=141) or within the STIR3 group (probability of edema 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 edema in T1/T2 series (volume of the type 1 part of MCs) (odds ratio: 1.0, 95% CI: 0.5, 2.3, n=104). Edema declined in >50% of patients in both treatment groups. CONCLUSIONS: From baseline to one-year follow-up, amoxicillin did not reduce MC edema compared with placebo. LEVEL OF EVIDENCE: 2.

A nationwide study of patients operated for cervical degenerative disorders in public and private hospitals.

During the last decades, there has been an increase in the rate of surgery for degenerative disorders of the cervical spine and in the use of supplementary private health insurance. Still, there is limited knowledge about the differences in characteristics of patients operated in public and private hospitals. Therefore, we aimed at comparing sociodemographic-, clinical- and patient management data on patients operated for degenerative cervical radiculopathy and degenerative cervical myelopathy in public and private hospitals in Norway. This was a cross-sectional study on patients in the Norwegian Registry for Spine Surgery operated for degenerative cervical radiculopathy and degenerative cervical myelopathy between January 2012 and December 2020. At admission for surgery, we assessed disability by the following patient reported outcome measures (PROMs): neck disability index (NDI), EuroQol-5D (EQ-5D) and numerical rating scales for neck pain (NRS-NP) and arm pain (NRS-AP). Among 9161 patients, 7344 (80.2%) procedures were performed in public hospitals and 1817 (19.8%) in private hospitals. Mean age was 52.1 years in public hospitals and 49.7 years in private hospitals (P < 0.001). More women were operated in public hospitals (47.9%) than in private hospitals (31.6%) (P < 0.001). A larger proportion of patients in private hospitals had high education (≥ 4 years of college or university) (42.9% vs 35.6%, P < 0.001). Patients in public hospitals had worse disease-specific health problems than those in private hospitals: unadjusted NDI mean difference was 5.2 (95% CI 4.4 - 6.0; P < 0.001) and adjusted NDI mean difference was 3.4 (95% CI 2.5 - 4.2; P < 0.001), and they also had longer duration of symptoms (P < 0.001). Duration of surgery (mean difference 29 minutes, 95% CI 27.1 - 30.7; P < 0.001) and length of hospital stay (mean difference 2 days, 95% CI 2.3 - 2.4; P < 0.001) were longer in public hospitals. In conclusion, patients operated for degenerative cervical spine in private hospitals were healthier, younger, better educated and more often men. They also had less and shorter duration of symptoms and seemed to be managed more efficiently. Our findings indicate that access to cervical spine surgery in private hospitals could be skewed in favour of patients with higher socioeconomic status.

Lifestyle behaviour in adolescence and musculoskeletal pain 11 years later: The Trøndelag Health Study.

BACKGROUND: There is limited knowledge on the association between lifestyle behaviour in adolescence and musculoskeletal pain in young adulthood. This study aimed to investigate whether an accumulation of adverse lifestyle behaviours in adolescents with and without musculoskeletal pain at baseline, was associated with persistent musculoskeletal pain (pain duration ≥3 consecutive months the last year) 11 years later. METHODS: Longitudinal data from the Trøndelag Health Study in Norway including 1824 adolescents (13-19 years old) was analysed. The outcome was persistent musculoskeletal pain (≥3 months). The number of adverse lifestyle behaviours (low physical activity level, sleep problems, insufficient fruit/vegetables consumption, smoking, frequent alcohol intoxication [drunkenness] and/or illicit drug use) were summed up to comprise an ordinal variable and analysed with 0 or 1 adverse behaviours as the reference. Multiple logistic regression analyses, stratified by individuals with and without baseline musculoskeletal pain, were conducted. The results were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: In adolescents with musculoskeletal pain at baseline, reporting ≥ four adverse lifestyle behaviours increased the odds of persistent musculoskeletal pain (OR 2.23, 95% CI 1.36, 3.66) 11 years later. Two and three adverse behaviours were not associated with future persistent musculoskeletal pain. In adolescents without musculoskeletal pain at baseline, an accumulation of adverse lifestyle behaviours was not associated with future persistent musculoskeletal pain. CONCLUSION: An accumulation of adverse lifestyle behaviours in adolescents with musculoskeletal pain at baseline was associated with persistent musculoskeletal pain 11 years later, but not in adolescents without musculoskeletal pain at baseline. SIGNIFICANCE: An accumulation of four or more adverse lifestyle behaviours in adolescents with musculoskeletal pain was associated with persistent musculoskeletal pain in young adulthood. In future health care of adolescents with musculoskeletal pain, lifestyle behaviours should be assessed, with emphasis on accumulation of multiple adverse lifestyle behaviours. Focusing on an accumulation of multiple adverse lifestyle behaviours, rather than each individual behaviour, might provide a potential area for future research and interventions targeting musculoskeletal pain in youth.

Clinical improvement after surgery for degenerative cervical myelopathy; A comparison of Patient-Reported Outcome Measures during 12-month follow-up.

OBJECT: Although many patients report clinical improvement after surgery due to degenerative cervical myelopathy, the aim of intervention is to stop progression of spinal cord dysfunction. We wanted to provide estimates and assess achievement rates of Minimal Clinically Important Difference (MCID) at 3- and 12-month follow-up for Neck Disability Index (NDI), Numeric Rating Scale for arm pain (NRS-AP) and neck pain (NRS-NP), Euro-Qol (EQ-5D-3L), and European Myelopathy Score (EMS). METHODS: 614 degenerative cervical myelopathy patients undergoing surgery responded to Patient-Reported Outcome Measures (PROMs) prior to, 3 and 12 months after surgery. External criterion was the Global Perceived Effect Scale (1-7), defining MCID as "slightly better", "much better" and "completely recovered". MCID estimates with highest sensitivity and specificity were calculated by Receiver Operating Curves for change and percentage change scores in the whole sample and in anterior and posterior procedural groups. RESULTS: The NDI and NRS-NP percentage change scores were the most accurate PROMs with a MCID of 16%. The change score for NDI and percentage change scores for NDI, NRS-AP and NRS-NP were slightly higher in the anterior procedure group compared to the posterior procedure group, while remaining PROM estimates were similar across procedure type. The MCID achievement rates at 12-month follow-up ranged from 51% in EMS to 62% in NRS-NP. CONCLUSION: The NDI and NRS-NP percentage change scores were the most accurate PROMs to measure clinical improvement after surgery for degenerative cervical myelopathy. We recommend using different cut-off estimates for anterior and posterior approach procedures. A MCID achievement rate of 60% or less must be interpreted in the perspective that the main goal of surgery for degenerative cervical myelopathy is to prevent worsening of the condition.

Cervical spine surgery in the Northern Norway Regional Health Authority area in 2014-18. / Nakkekirurgi i Helse Nord 2014­18.

BACKGROUND: Knowledge about the variation in treatment rates is needed to assess whether the access to health services is equitable. The objective of this study was to investigate the rates of surgical treatment of degenerative cervical spine disease in Norway and the Northern Norway Regional Health Authority area and the local coverage in the Northern Norway Regional Health Authority area, and to assess the activity in the region. MATERIAL AND METHOD: We included cervical spine procedures recorded in the Norwegian Patient Registry from the years 2014-18 and estimated age-standardised treatment rates for Norway, the health regions and health trusts in Northern Norway Regional Health Authority. We estimated the local coverage as the proportion of patients resident in the Northern Norway Regional Health Authority area who had undergone surgery at the University Hospital of North Norway in Tromsø. RESULTS: The treatment rate remained stable at an average of 29.6 surgical procedures per 100 000 inhabitants (aged 18-105) per year. The rate for residents in the Northern Norway Regional Health Authority area was 23.0 procedures per 100 000 inhabitants per year (78 % of the national average). The rates in Finnmark and the areas of residence served by the University Hospital of North Norway were close to the national average. Residents in the Nordland and Helgeland areas had lower rates in each year of the study period, with an average of 16.6 and 18.1 procedures per 100 000 inhabitants per year respectively. This corresponds to 56 % and 61 % of the national average. Local coverage in the Northern Norway Regional Health Authority area increased from 69 % in 2014 to 91 % in 2018. INTERPRETATION: The treatment rate for degenerative cervical spine disease was lower in the Northern Norway Regional Health Authority area than in the rest of Norway. For this to be compensated and the local coverage to be increased to 100 %, we have estimated that the activity needs to be increased by approximately 35 surgical procedures per year.

A prognostic model for failure and worsening after lumbar microdiscectomy: a multicenter study from the Norwegian Registry for Spine Surgery.

OBJECTIVE: To develop a prognostic model for failure and worsening 1 year after surgery for lumbar disc herniation. METHODS: This multicenter cohort study included 11,081 patients operated with lumbar microdiscectomy, registered at the Norwegian Registry for Spine Surgery. Follow-up was 1 year. Uni- and multivariate logistic regression analyses were used to assess potential prognostic factors for previously defined cut-offs for failure and worsening on the Oswestry Disability Index scores 12 months after surgery. Since the cut-offs for failure and worsening are different for patients with low, moderate, and high baseline ODI scores, the multivariate analyses were run separately for these subgroups. Data were split into a training (70%) and a validation set (30%). The model was developed in the training set and tested in the validation set. A prediction (%) of an outcome was calculated for each patient in a risk matrix. RESULTS: The prognostic model produced six risk matrices based on three baseline ODI ranges (low, medium, and high) and two outcomes (failure and worsening), each containing 7 to 11 prognostic factors. Model discrimination and calibration were acceptable. The estimated preoperative probabilities ranged from 3 to 94% for failure and from 1 to 72% for worsening in our validation cohort. CONCLUSION: We developed a prognostic model for failure and worsening 12 months after surgery for lumbar disc herniation. The model showed acceptable calibration and discrimination, and could be useful in assisting physicians and patients in clinical decision-making process prior to surgery.

Treatment rates for lumbar spine surgery in Norway and Northern Norway Regional Health Authority 2014-18. / Behandlingsrater for ryggkirurgi i Norge og Helse Nord 2014­18.

BACKGROUND: The objective of this study was to investigate whether the service provision for lumbar spine surgery within the Northern Norway Regional Health Authority area complies with the distribution of functions that has been decided for the hospitals in the region, and whether there are any geographical variations in service provision. We therefore studied the treatment rates in Norway as a whole and in the Northern Norway Regional Health Authority area, and assessed the activity in the region. MATERIAL AND METHOD: We included lumbar spine procedures in the Norwegian Patient Registry from the years 2014-2018 in a retrospective analysis and estimated treatment rates standardised by sex and age for Norway as a whole, the health regions and the health enterprises in Northern Norway Regional Health Authority. We estimated the local coverage as the proportion of patients who had undergone surgery in a hospital within their own area of residence. RESULTS: The treatment rate for lumbar spine surgery in Norway amounted to approximately 120 procedures per 100 000 inhabitants per year for the entire period. The number of spine procedures nationwide increased from 5 995 in 2014 to 6 494 in 2018 because of a general population growth. The treatment rates for fractures and simple spine procedures were approximately identical throughout Norway, but the rate for complex spine procedures among residents within the area of Northern Norway Regional Health Authority amounted to 57 % of the national average. Local coverage within the Northern Norway Regional Health Authority area increased from 60 % to 84 % during the period. The local hospital functions for simple spine procedures at Nordland and Helgeland hospitals (approximately 30 %) and the regional function for complex spine surgery at the University Hospital of North Norway (55 %) had a low degree of local coverage. INTERPRETATION: The treatment rate for complex spine procedures and the local coverage for all surgical procedures for degenerative lumbar spine disease were lower within the Northern Norway Regional Health Authority area than in the country as a whole. For this to be compensated in this region, we have estimated that the activity needs to be increased by approximately 170 procedures per year.

Acupuncture for acute non-specific low back pain: a randomised, controlled, multicentre intervention study in general practice-the Acuback study.

OBJECTIVES: The aim of this study was to evaluate whether a single treatment session of acupuncture, when applied in addition to standard treatment for acute low back pain (ALBP), reduces the time to recovery compared with standard treatment alone. DESIGN: A multicentre, randomised, controlled trial. SETTING: Conducted at 11 Norwegian general practitioners' (GPs') offices. PARTICIPANTS: 171 adults aged 20-55 years seeking their GP for ALBP (≤14 days) between March 2014 and March 2017. Patients with secondary back pain and previous sick leave and acupuncture treatment was excluded. INTERVENTIONS: The participants were randomised to either the control group (CG) or the acupuncture group (AG) by online software. The CG received standard treatment according to the Norwegian guidelines, while the AG received one session of Western medical acupuncture treatment in addition to standard treatment. The statistician was blinded to group status. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was median days to recovery. Secondary outcomes were pain intensity, global improvement, back-specific functional status, sick leave, medication and adverse effects. RESULTS: 185 participants were randomised, 95 in the CG and 90 in the AG. 14 participants did not receive the allocated intervention and 4 were excluded from the analysis. Thus, 167 participants were included in the analysis, 86 in the CG and 81 in the AG. The groups were similar according to baseline characteristics. The median time to recovery was 14 days for the CG and 9 days for the AG, HR 1.37 (95% CI 0.95 to 1.96), (p=0.089). No serious adverse effects were reported. CONCLUSIONS: We did not find any statistically significant reduction in time-to-recovery after a single session of acupuncture for ALBP compared with standard care. TRIAL REGISTRATION NUMBER: NCT01439412.

Clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes - secondary analyses of a randomised, placebo-controlled trial (the AIM study).

BACKGROUND: Randomised trials on antibiotic treatment for patients with chronic low back pain and vertebral endplate changes visible on MRI (Modic changes) have shown mixed results. A possible explanation might be a real treatment effect in subgroups of the study populations. The purpose of the present study was to explore potential clinical effect modifiers of 3-months oral amoxicillin treatment in patients with chronic low back pain and type I or II Modic changes at the level of a previous lumbar disc herniation. METHODS: We performed analyses of effect modifiers on data from AIM, a double-blind parallel-group multicentre trial. One hundred eighty patients with chronic low back pain, previous disc herniation, Modic change type I (n = 118) or type II (n = 62) were randomised to 3-months oral treatment with 750 mg amoxicillin (n = 89) or placebo (n = 91) three times daily. The primary outcome was the Roland-Morris Disability Questionnaire (RMDQ) score (possible values 0-24) at 1-year follow-up in the intention-to-treat population. The predefined minimal clinically important between-group mean difference was 4 RMDQ points (not reached in the primary analysis of AIM). Predefined baseline characteristics were analysed as potential effect modifiers, four primary (type I Modic changes, previous disc surgery, positive pain provocation test, high CRP) and five exploratory (disturbed sleep, constant low back pain, short duration of low back pain, younger age, and male) using ANCOVA with interaction terms. RESULTS: None of the four primary potential effect modifiers had strong evidence of modifying the treatment effect. In patients younger than 40 years the difference in mean RMDQ score between the treatment groups was - 4.0 (95%CI, - 6.9 to - 1.2), compared to - 0.5 (95%CI, - 2.3 to 1.3) in patients 40 years or older, both in favour of amoxicillin treatment (exploratory analysis). CONCLUSIONS: We did not find evidence for convincing clinical effect modifiers of antibiotic treatment in patients with chronic low back pain and Modic changes. Our results for younger age in these explorative analyses should not affect clinical treatment decisions without confirmation in future studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT02323412 , First registered 23 December 2014.

Cost-utility analysis of antibiotic treatment in patients with chronic low back pain and Modic changes: results from a randomised, placebo-controlled trial in Norway (the AIM study).

OBJECTIVE: To 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. DESIGN: A cost-utility analysis from a societal and healthcare perspective alongside a double-blinded, parallel group, placebo, multicentre trial. SETTING: Hospital 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. PARTICIPANTS: 180 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). INTERVENTIONS: Oral treatment with either 750 mg amoxicillin or placebo three times daily for 100 days. MAIN OUTCOME MEASURES: Quality-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). RESULTS: Mean (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%. CONCLUSIONS: Amoxicillin treatment showed no evidence of being cost-effective for people with chronic LBP and Modic changes during 1-year follow-up. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02323412.

Association of Modic change types and their short tau inversion recovery signals with clinical characteristics- a cross sectional study of chronic low back pain patients in the AIM-study.

BACKGROUND: Modic Changes (MCs, magnetic resonance imaging (MRI) signal changes in the vertebral bone marrow extending from the vertebral endplate) may represent a subgroup of nonspecific chronic low back pain that could benefit from a specific management. The primary aim was to compare clinical characteristics between patients with type 1 versus type 2 MCs. The secondary aim was to explore associations between clinical characteristics and MC related short tau inversion recovery (STIR) signals. METHODS: This cross-sectional study used baseline data prospectively collected between 2015 and 2017 on the 180 patients included in the AIM-study (Antibiotics In Modic changes), a randomized controlled trial in a Norwegian hospital out-patient setting of patients with chronic low back pain, a lumbar disc herniation within the last 2 years, low back pain intensity score ≥ 5 (on a 0-10 scale) and current type 1 or type 2 MCs at the previously herniated lumbar disc level. We used prespecified clinical characteristics including self-report measures, physiologic measures and functional measures from clinical history and examination. The diagnostic accuracy of various clinical characteristics to discriminate between patients with type 1 MCs (with or without additional type 2 MCs) and patents with type 2 MCs only (not type 1) were assessed by calculating the area under the receiver-operating curve. We assessed the correlations of clinical characteristics with details of MC related STIR signal increase. RESULTS: No clinical characteristic differed between patients with type 1 (n = 118) versus type 2 (but not type 1) (n = 62) MCs. The clinical characteristics showed no/minor differences or no/weak correlations with MC related STIR signal increase. Patients with a positive Springing test (at any lumbar level) had slightly less volume of STIR signal increase than those with a negative test (mean difference 1.3 on a 0-48 scale, 95% CI 0.3 to 2.3). CONCLUSION: Clinical characteristics were similar for patients with type 1 MCs and patients with type 2 MCs, and showed no clinically relevant correlations with MC related STIR signal increase. TRIAL REGISTRATION: ClinicalTrials.gov NCT02323412, First registered 23 December 2014.

Criteria for success after surgery for cervical radiculopathy-estimates for a substantial amount of improvement in core outcome measures.

BACKGROUND CONTEXT: Defining clinically meaningful success criteria from patient-reported outcome measures (PROMs) is crucial for clinical audits, research and decision-making. PURPOSE: We aimed to define criteria for a successful outcome 3 and 12 months after surgery for cervical degenerative radiculopathy on recommended PROMs. STUDY DESIGN: Prospective cohort study with 12 months follow-up. PATIENT SAMPLE: Patients operated at one or two levels for cervical radiculopathy included in the Norwegian Registry for Spine Surgery (NORspine) from 2011 to 2016. OUTCOME MEASURES: Neck disability index (NDI), Numeric Rating Scale for neck pain (NRS-NP) and arm pain (NRS-AP), health-related quality-of-life EuroQol 3L (EQ-5D), general health status (EQ-VAS). METHODS: We included 2,868 consecutive cervical degenerative radiculopathy patients operated for cervical radiculopathy in one or two levels and included in the Norwegian Registry for Spine Surgery (NORspine). External criterion to determine accuracy and optimal cut-off values for success in the PROMs was the global perceived effect scale. Success was defined as "much better" or "completely recovered." Cut-off values were assessed by analyzing the area under the receiver operating curves for follow-up scores, mean change scores, and percentage change scores. RESULTS: All PROMs showed high accuracy in defining success and nonsuccess and only minor differences were found between 3- and 12-month scores. At 12 months, the area under the receiver operating curves for follow-up scores were 0.86 to 0.91, change scores were 0.74 to 0.87, and percentage change scores were 0.74 to 0.91. Percentage scores of NDI and NRS-AP showed the best accuracy. The optimal cut-off values for each PROM showed considerable overlap across those operated due to disc herniation and spondylotic foraminal stenosis. CONCLUSIONS: All PROMs, especially NDI and NRS-AP, showed good to excellent discriminative ability in distinguishing between a successful and nonsuccessful outcome after surgery due to cervical radiculopathy. Percentage change scores are recommended for use in research and clinical practice.

Can a Successful Outcome After Surgery for Lumbar Disc Herniation Be Defined by the Oswestry Disability Index Raw Score?

STUDY DESIGN: Prospective multicenter cohort study. OBJECTIVE: To investigate (1) the discriminative ability and cutoff estimates for success 12 months after surgery for lumbar disc herniation on the Oswestry Disability Index (ODI) raw score compared with a change and a percentage change score and (2) to what extent these clinical outcomes depend on the baseline disability. METHODS: A total of 6840 patients operated for lumbar disc herniation from the Norwegian Registry for Spine Surgery (NORspine) were included. In receiver operating characteristic (ROC) curve analyses, a global perceived effect (GPE) scale (1-7) was used an external anchor. Success was defined as categories 1-2, "completely recovered" and "much better." Cutoffs for success for subgroups with different preoperative disability were also estimated. RESULTS: When defining success after surgery for lumbar disc herniation, the accuracy (sensitivity, specificity, area under the curve, 95% CI) for the ODI raw score (0.83, 0.87, 0.930, 0.924-0.937) was comparable to the ODI percentage change score (0.85, 0.85, 0.925, 0.918-0.931), and higher than the ODI change score (0.79, 0.73, 0.838, 0.830-0.852). The cutoff for success was highly dependent on the amount of baseline disability (low-high), with cutoffs ranging from 13 to 28 for the ODI raw score and 39% to 66% for ODI percentage change. The ODI change score (points) was not as accurate. CONCLUSION: The 12-month ODI raw score, like the ODI percentage change score, can define a successful outcome with excellent accuracy. Adjustment for the baseline ODI score should be performed when comparing outcomes across groups, and one should consider using cutoffs according to preoperative disability (low, medium, high ODI scores).