Twenty-year perspective of randomized controlled trials for surgery of chronic nonspecific low back pain: citation bias and tangential knowledge

Surgical treatment of refractory low back pain using implanted BurstDR spinal cord stimulation (SCS) in a cohort of patients without options for corrective surgery: Findings and results from the DISTINCT study, a prospective randomized multi-center-controlled trial

Background

Low back pain (LBP) is a highly prevalent, disabling condition affecting millions of people. Patients with an identifiable anatomic pain generator and resulting neuropathic lower extremity symptoms often undergo spine surgery, but many patients lack identifiable and/or surgically corrective pathology. Nonoperative treatment options often fail to provide sustained relief. Spinal cord stimulation (SCS) is sometimes used to treat these patients, but the lack of level 1 evidence limits its widespread use and insurance coverage. The DISTINCT RCT study evaluates the efficacy of passive recharge burst SCS compared to conventional medical treatment (CMM) in alleviating chronic, refractory axial low back pain.

Methods

This prospective, multicenter, randomized, study with an optional 6-month crossover involved patients who were not candidates for lumbar spine surgery. The primary and secondary endpoints evaluated improvements in low back pain intensity (NRS), back pain-related disability (ODI), pain catastrophizing (PCS), and healthcare utilization. Patients were randomized to SCS therapy or CMM at 30 US study sites.

Results

The SCS arm reported an 85.3% NRS responder rate (≥ 50% reduction) compared to 6.2% (5/81) in the CMM arm. After the 6M primary endpoint, SCS patients elected to remain on assigned therapy and 66.2% (49/74) of CMM patients chose to trial SCS (crossover). At the 12M follow-up, SCS and crossover patients reported 78.6% and 71.4% NRS responder rates. Secondary outcomes indicated significant improvements in ODI, PCS, and reduced healthcare utilization. Six serious adverse events were reported and resolved without sequelae.

Conclusion

DISTINCT chronic low back pain patients with no indication for corrective surgery experienced a significant and sustained response to burst SCS therapy for up to 12 months. CMM patients who crossed over to the SCS arm reported profound improvements after 6 months. This data advocates for a timely consideration of SCS therapy in patients unresponsive to conservative therapy.

Repeat Discectomy or Instrumented Surgery for Recurrent Lumbar Disk Herniation: An Overview of French Spine Surgeons' Practice

STUDY DESIGN

Retrospective multicenter cohort study.

OBJECTIVE

Recurrent lumbar disc herniation (ReLDH) is a common condition requiring surgical intervention in a large proportion of cases. Evidence regarding the appropriate choice between repeat microdiscectomy (RD) and instrumented surgery (IS) is lacking. To understand the indications for either of the procedures and compare the results, we aimed to provide an overview of spine surgeon practice in France.

METHODS

This retrospective, multicenter analysis included adults who underwent surgery for ReLDHs between December 2020 and May 2021. Surgeons were asked which of the following factors determined their therapeutic choice: radio-clinical considerations, non-discal anatomical factors, patient preference, or surgeon background. Data on preoperative clinical status and radiologic findings were collected. Patient-reported outcome measures (PROMs) were assessed and compared using propensity scores preoperatively and at 3 and 12 months postoperatively.

RESULTS

The study included 150 patients (72 IS and 78 RD). Radioclinical elements, anatomical data, patient preferences, and surgeon background influenced the choice of RD in 57.7%, 1.3%, 25.6%, and 15.4% of the cases, respectively, and IS in 34.7%, 6.9%, 13.9%, and 44.5% of the cases, respectively. At 12 months, patient satisfaction, return to work, and changes in PROMs were not significantly different between the groups.

CONCLUSIONS

The decision-making process included both objective and subjective factors, resulting in patient satisfaction in 80.3% to 81.5% of cases, with significant clinical improvement in radicular symptoms in 75.8% to 91.8% of cases, and quality of life in 75.8% to 84.9% of cases, depending on the procedure performed.

The Immediate Effects of Muscle Energy Technique in Chronic Low Back Pain Patients with Functional Leg Length Discrepancy: A Randomized and Placebo-Controlled Trial

This study was conducted to determine the effect of muscle energy technique (MET) on pelvic alignment, leg length, pain, and fatigue in chronic low back pain (CLBP) patients with leg length discrepancy (LLD). Forty-two CLBP patients with LLD volunteered to participate and were randomly assigned to the MET group (n = 21) and placebo group (n = 21). The intervention group performed three METs with 5 s of isometric contraction and 30 s of rest once, and the placebo group performed three times the placebo-MET, maintaining the same posture as the MET group without muscle isometric contraction. X-ray equipment, tape measure, and visual analog scale were used to evaluate pelvic alignment, leg length, pain, and fatigue before and after each intervention. In comparison pre- and postintervention, only the MET group showed significant changes in pelvic alignment, leg length, pain, and fatigue (p < 0.05). In comparison between groups, there were significant differences in all variables (pelvic alignment, leg length, pain, fatigue) (p < 0.05). The results of this study confirmed the therapeutic effect of MET for improving pelvic alignment, functional LLD, pain, and fatigue in CLBP patients with functional LLD. Future research is needed to evaluate the long-term effect on more chronic low back pain patients.

The role of spinal surgery in the treatment of low back pain

Low back pain (LBP) is common and a leading cause of disability and lost productivity worldwide. Acute LBP is frequently self-resolving, but recurrence is common, and a significant proportion of patients will develop chronic pain. This transition is perpetuated by anatomical, biological, psychological and social factors. Chronic LBP should be managed with a holistic biopsychosocial approach of generally non-surgical measures. Spinal surgery has a role in alleviating radicular pain and disability resulting from neural compression, or where back pain relates to cancer, infection, or gross instability. Spinal surgery for all other forms of back pain is unsupported by clinical data, and the broader evidence base for spinal surgery in the management of LBP is poor and suggests it is ineffective. Emerging areas of interest include selection of a minority of patients who may benefit from surgery based on spinal sagittal alignment and/or nuclear medicine scans, but an evidence base is absent. Spinal surgery for back pain has increased substantially over recent decades, and disproportionately among privately insured patients, thus the contribution of industry and third-party payers to this increase, and their involvement in published research, requires careful consideration.

Meta-research evaluating redundancy and use of systematic reviews when planning new studies in health research: a scoping review

BACKGROUND

Several studies have documented the production of wasteful research, defined as research of no scientific importance and/or not meeting societal needs. We argue that this redundancy in research may to a large degree be due to the lack of a systematic evaluation of the best available evidence and/or of studies assessing societal needs.

OBJECTIVES

The aim of this scoping review is to (A) identify meta-research studies evaluating if redundancy is present within biomedical research, and if so, assessing the prevalence of such redundancy, and (B) to identify meta-research studies evaluating if researchers had been trying to minimise or avoid redundancy.

ELIGIBILITY CRITERIA

Meta-research studies (empirical studies) were eligible if they evaluated whether redundancy was present and to what degree; whether health researchers referred to all earlier similar studies when justifying and designing a new study and/or when placing new results in the context of earlier similar trials; and whether health researchers systematically and transparently considered end users' perspectives when justifying and designing a new study.

SOURCES OF EVIDENCE

The initial overall search was conducted in MEDLINE, Embase via Ovid, CINAHL, Web of Science, Social Sciences Citation Index, Arts & Humanities Citation Index, and the Cochrane Methodology Register from inception to June 2015. A 2nd search included MEDLINE and Embase via Ovid and covered January 2015 to 26 May 2021. No publication date or language restrictions were applied.

CHARTING METHODS

Charting methods included description of the included studies, bibliometric mapping, and presentation of possible research gaps in the identified meta-research.

RESULTS

We identified 69 meta-research studies. Thirty-four (49%) of these evaluated the prevalence of redundancy and 42 (61%) studies evaluated the prevalence of a systematic and transparent use of earlier similar studies when justifying and designing new studies, and/or when placing new results in context, with seven (10%) studies addressing both aspects. Only one (1%) study assessed if the perspectives of end users had been used to inform the justification and design of a new study. Among the included meta-research studies evaluating whether redundancy was present, only two of nine health domains (medical areas) and only two of 10 research topics (different methodological types) were represented. Similarly, among the included meta-research studies evaluating whether researchers had been trying to minimise or avoid redundancy, only one of nine health domains and only one of 10 research topics were represented.

CONCLUSIONS THAT RELATE TO THE REVIEW QUESTIONS AND OBJECTIVES

Even with 69 included meta-research studies, there was a lack of information for most health domains and research topics. However, as most included studies were evaluating across different domains, there is a clear indication of a high prevalence of redundancy and a low prevalence of trying to minimise or avoid redundancy. In addition, only one meta-research study evaluated whether the perspectives of end users were used to inform the justification and design of a new study.

SYSTEMATIC REVIEW REGISTRATION

Protocol registered at Open Science Framework: https://osf.io/3rdua/ (15 June 2021).

Citation bias and other determinants of citation in biomedical research: findings from six citation networks

OBJECTIVES

When the probability of being cited depends on the outcome of that study, this is called citation bias. The aim of this study is to assess the determinants of citation and how these compare across six different biomedical research fields.

STUDY DESIGN AND SETTING

Citation network analyses were performed for six biomedical research questions. After identifying all relevant publications, all potential citations were mapped together with the actually performed citations in each network. As determinants of citation we assessed the following: study outcome, study design, sample size, journal impact factor, gender, affiliation, authority and continent of the corresponding author, funding source, title of the publication, number of references, and self-citation. Random effect logistic regression analysis was used to assess these factors.

RESULTS

Four out of six networks showed evidence for citation bias. Self-citation, authority of the author, and journal impact factor were also positively associated with the probability of citation in all networks.

CONCLUSION

The probability of being cited seems associated with positive study outcomes, the authority of its authors, and the journal in which that article is published. In addition, each network showed specific characteristics that impact the citation dynamics and that need to be considered when performing and interpreting citation analyses.

Determinants of citation in the literature on diesel exhaust exposure and lung cancer: a citation analysis

OBJECTIVES

Epidemiological research on the association between diesel exhaust exposure and lung cancer risk has some methodological challenges that give rise to different conclusions and intense debates. This raises the question about the role of selective citation and of citation bias in particular. Our aim was to investigate the occurrence and prevalence of selective citation in this field.

DESIGN

Citation analysis.

SETTING

Web of Science Core Collection.

PARTICIPANTS

We identified 96 publications in this network, with 4317 potential citations. For each publication, we extracted characteristics such as study conclusion and funding source. Some of these characteristics are related to the study content: study design, sample size, method of diesel exposure assessment, type of diesel technology under investigation, and whether smoking had been adjusted for.

PRIMARY AND SECONDARY OUTCOME MEASURES

Whether a citation occurs or not, measured and analysed according to the preregistered protocol. Exploratively we analysed the association between funding source and study conclusion.

RESULTS

Methodological content of a study was clearly related to citation, studies using more sophisticated methods were more likely to be cited. There was some evidence for citation bias: supportive publications had a higher chance of being cited than non-supportive ones, but after adjustment for study quality, this effect decreased substantially (adjusted OR 1.3, 95% CI 1.0 to 1.7). Explorative analyses indicated that three quarters of non-profit funded publications had a supportive study conclusion against only one quarter of the industry-funded publications.

CONCLUSIONS

There is evidence for selective citation within this field, but the evidence for citation bias was weak. It seems that factors related to the methodology had more impact on citation than the conclusion of a study. Interestingly, publications that were funded by industry were more skeptical about a causal relationship between diesel exhaust and lung cancer compared to non-profit-funded publications.

Evidence-Based Research Series-Paper 2 : Using an Evidence-Based Research approach before a new study is conducted to ensure value

BACKGROUND AND OBJECTIVES

There is considerable actual and potential waste in research. The aim of this article is to describe how using an evidence-based research approach before conducting a study helps to ensure that the new study truly adds value.

STUDY DESIGN AND SETTING

Evidence-based research is the use of prior research in a systematic and transparent way to inform a new study so that it is answering questions that matter in a valid, efficient, and accessible manner. In this second article of the evidence-based research series, we describe how to apply an evidence-based research approach before starting a new study.

RESULTS

Before a new study is performed, researchers need to provide a solid justification for it using the available scientific knowledge as well as the perspectives of end users. The key method for both is to conduct a systematic review of earlier relevant studies.

CONCLUSION

Describing the ideal process illuminates the challenges and opportunities offered through the suggested evidence-based research approach. A systematic and transparent approach is needed to provide justification for and to optimally design a relevant and necessary new study.

Evidence-Based Research Series-Paper 1: What Evidence-Based Research is and why is it important?

OBJECTIVES

There is considerable actual and potential waste in research. Evidence-based research ensures worthwhile and valuable research. The aim of this series, which this article introduces, is to describe the evidence-based research approach.

STUDY DESIGN AND SETTING

In this first article of a three-article series, we introduce the evidence-based research approach. Evidence-based research is the use of prior research in a systematic and transparent way to inform a new study so that it is answering questions that matter in a valid, efficient, and accessible manner.

RESULTS

We describe evidence-based research and provide an overview of the approach of systematically and transparently using previous research before starting a new study to justify and design the new study (article #2 in series) and-on study completion-place its results in the context with what is already known (article #3 in series).

CONCLUSION

This series introduces evidence-based research as an approach to minimize unnecessary and irrelevant clinical health research that is unscientific, wasteful, and unethical.

Selective citation in the literature on the hygiene hypothesis: a citation analysis on the association between infections and rhinitis

OBJECTIVE

Our objective was to assess the occurrence and determinants of selective citation in scientific publications on Strachan's original hygiene hypothesis. His hypothesis states that lack of exposure to infections in early childhood increases the risk of rhinitis.

SETTING

Web of Science Core Collection.

PARTICIPANTS

We identified 110 publications in this network, consisting of 5551 potential citations.

PRIMARY AND SECONDARY OUTCOME MEASURES

Whether a citation occurs or not, measured and analysed according to the preregistered protocol.

RESULTS

We found evidence for citation bias in this field: publications supportive of the hypothesis were cited more often than non-supportive publications (OR adjusted for study design [adjOR] 2.2, 95% CI 1.6 to 3.1), and the same was the case for publications with mixed findings (adjOR 3.1, 95% CI 2.2 to 4.5). Other relevant determinants for citation were type of exposure, specificity, journal impact factor, authority and self-citation. Surprisingly, prospective cohort studies were cited less often than other empirical studies.

CONCLUSIONS

There is clear evidence for selective citation in this research field, and particularly for citation bias.

Magnetic resonance spectroscopy (MRS) can identify painful lumbar discs and may facilitate improved clinical outcomes of lumbar surgeries for discogenic pain

PURPOSE

The goal of this study was to refine clinical MRS to optimize performance and then determine whether MRS-derived biomarkers reliably identify painful discs, quantify degeneration severity, and forecast surgical outcomes for chronic low back pain (CLBP) patients.

METHODS

We performed an observational diagnostic development and accuracy study. Six hundred and twenty-three (623) discs in 139 patients were scanned using MRS, with 275 discs also receiving provocative discography (PD). MRS data were used to quantify spectral features related to disc structure (collagen and proteoglycan) and acidity (lactate, alanine, propionate). Ratios of acidity to structure were used to calculate pain potential. MRS-SCOREs were compared to PD and Pfirrmann grade. Clinical utility was judged by evaluating surgical success for 75 of the subjects who underwent lumbar surgery.

RESULTS

Two hundred and six (206) discs had both a successful MRS and independent pain diagnosis. When comparing to PD, MRS had a total accuracy of 85%, sensitivity of 82%, and specificity of 88%. These increased to 93%, 91%, and 93% respectively, in non-herniated discs. The MRS structure measures differed significantly between Pfirrmann grades, except grade I versus grade II. When all MRS positive discs were treated, surgical success was 97% versus 57% when the treated level was MRS negative, or 54% when the non-treated adjacent level was MRS positive.

CONCLUSION

MRS correlates with PD and may support improved surgical outcomes for CLBP patients. Noninvasive MRS is a potentially valuable approach to clarifying pain mechanisms and designing CLBP therapies that are customized to the patient. These slides can be retrieved under Electronic Supplementary Material.

Citation bias in the literature on dietary trans fatty acids and serum cholesterol

OBJECTIVE

Balanced citations are a necessary condition for a sound development of scientific knowledge, whereas selective citations may bias scientific consensus. In this study, we assess which determinants influenced the likelihood of being cited in the literature on trans fatty acids and cholesterol.

STUDY DESIGN AND SETTING

We conducted a citation network analysis of the literature concerning trans fats and low density cholesterol and high density cholesterol. Each publication was scored on various potential determinants of citation, such as study outcome, study design, sample size, journal impact factor, and funding source. We applied random effect logistic regression to identify determinants of citation.

RESULTS

A network of 108 publications was identified, containing 5,041 potential citation paths and 669 utilized citation paths. Reporting statistically significant results was found to be a strong predictor of citation, together with sample size, journal impact factor, and the authority of the authors.

CONCLUSION

Within the literature on trans fat intake and cholesterol, selective citations are based on several grounds. Especially the effect of reporting significant results on citation requires special attention because disproportionate attention is paid to publications suggesting a harmful effect of trans fat on cholesterol.

Efficacy and Safety of Different Aceclofenac Treatments for Chronic Lower Back Pain: Prospective, Randomized, Single Center, Open-Label Clinical Trials

PURPOSE

Nonsteroidal anti-inflammatory drugs are a mainstay for medical treatment of chronic lower back pain (CLBP). Increased dose intervals for medication have been associated with increased patient adherence to prescriptions. The purpose of this clinical trial was to compare the efficacy and safety of a once daily dose of aceclofenac controlled release (CR) and a twice daily dose of aceclofenac for CLBP management.

MATERIALS AND METHODS

A prospective, randomized, single center, open-label clinical trial was performed to compare the efficacy and safety of aceclofenac CR (200 mg once daily) to aceclofenac dose (100 mg twice daily). Fifty patients in each group were enrolled for the study. The primary end point was Visual Analogue Scale (VAS) change at baseline to that at 2 weeks after medication and safety profiles. Also, change in quality of life measured by EuroQoL 5D (EQ-5D) and Oswestry Disability Index (ODI) functional score for the lumbar spine were also assessed.

RESULTS

Within groups at pre- and post-treatment, there were significant VAS reductions for aceclofenac CR and aceclofenac (p=0.028). EQ-5D increased significantly in both groups (p=0.037). ODI scores decreased significantly in both groups (p=0.012). However, there were no significant differences between aceclofenac CR and aceclofenac at pre- and post-treatment. Patients with aceclofenac CR showed significant increases in heartburn and indigestion and adverse gastrointestinal effects, compared to aceclofenac.

CONCLUSION

In patients with CLBP, aceclofenac CR and aceclofenac demonstrated significant symptomatic pain relief, improvement in quality of life and functional scores. Aceclofenac CR slightly increased gastrointestinal adverse effects, such as heartburn and indigestion.

mDurance: A Novel Mobile Health System to Support Trunk Endurance Assessment

Low back pain is the most prevalent musculoskeletal condition. This disorder constitutes one of the most common causes of disability worldwide, and as a result, it has a severe socioeconomic impact. Endurance tests are normally considered in low back pain rehabilitation practice to assess the muscle status. However, traditional procedures to evaluate these tests suffer from practical limitations, which potentially lead to inaccurate diagnoses. The use of digital technologies is considered here to facilitate the task of the expert and to increase the reliability and interpretability of the endurance tests. This work presents mDurance, a novel mobile health system aimed at supporting specialists in the functional assessment of trunk endurance by using wearable and mobile devices. The system employs a wearable inertial sensor to track the patient trunk posture, while portable electromyography sensors are used to seamlessly measure the electrical activity produced by the trunk muscles. The information registered by the sensors is processed and managed by a mobile application that facilitates the expert's normal routine, while reducing the impact of human errors and expediting the analysis of the test results. In order to show the potential of the mDurance system, a case study has been conducted. The results of this study prove the reliability of mDurance and further demonstrate that practitioners are certainly interested in the regular use of a system of this nature.

Does a preoperative cognitive-behavioral intervention affect disability, pain behavior, pain, and return to work the first year after lumbar spinal fusion surgery?

STUDY DESIGN

A randomized clinical trial including 90 patients.

OBJECTIVE

To examine the effect of a preoperative cognitive-behavioral intervention (CBT) for patients undergoing lumbar spinal fusion (LSF) surgery.

SUMMARY OF BACKGROUND DATA

Few published studies have looked at the potential of rehabilitation to improve outcomes after LSF. Rehabilitation programs using CBT are recommended. Furthermore, initiating interventions preoperatively seems beneficial, but only limited data exist in the field of spine surgery.

METHODS

Patients with degenerative disc disease or spondylolisthesis undergoing LSF were randomized to usual care (control group) or preoperative CBT and usual care (CBT group). Primary outcome was change in Oswestry Disability Index from baseline to 1-year follow-up. Secondary outcomes were catastrophizing, fear avoidance belief, work status, and back and leg pain.

RESULTS

At 1-year follow-up, there was no statistically significant difference between the CBT group and the control group in Oswestry Disability Index score (P = 0.082). However, the CBT group had achieved a significant reduction of -15 points (-26; -4) already at 3 months (between group difference P = 0.003), and this reduction was maintained throughout the year. There were no differences between groups at 1-year follow-up with regard to any of the secondary outcomes.

CONCLUSION

Participating in a preoperative CBT intervention in addition to usual care did not produce better outcomes at 1-year follow-up for patients undergoing LSF. Although the reduction in disability was achieved much faster in the CBT group, resulting in a significant difference between groups already 3 months after surgery, it did not translate into a faster return to work. Our findings support the need for further research into the use of targeted rehabilitation interventions among patients with elevated levels of catastrophizing and fear avoidance beliefs.

LEVEL OF EVIDENCE

2.

[Multimodal therapy programs for chronic pain]

Chronic pain is a common and disabling disorder with major consequences for patient quality of life and it is also a major economic burden to society. The management of chronic pain comprises a large range of different intervention strategies including pharmacological therapy, non-medicinal and invasive therapeutic options. While non-pharmacological and multimodal options are underused, monomodal options, especially pharmacotherapy and invasive therapies are overused. The effectiveness of multidisciplinary and multimodal treatment programs including physical and rehabilitation interventions and psychological treatment has been extensively studied in the last two decades. Evidence from randomized controlled trials demonstrates that there is low quality evidence for the effectiveness of exercise therapy alone, there is some evidence for the effectiveness of behavioral therapy and there is at least moderate evidence for the effectiveness of multidisciplinary and multimodal treatment and other active treatment reducing pain and increasing functional capacity at short and intermediate term. Therefore, blanket coverage with provision of adequate treatment programs for chronic pain as well as studies evaluating the best composition of treatment elements are needed. The characteristics of chronic pain, the necessary assessment procedures and treatment types are described.