Trials

[Jo Bowyer]

Effectiveness analysis of an internet-based intervention for overweight adolescents: next steps for researchers and clinicians

http://bmcobes.biomedcentral.com/art...608-016-0094-4

Abstract

Backgrounds
The development of effective strategies for the management of overweight in adolescence is a well recognized need. The current study investigates the effectiveness of an e-therapeutic platform (Next.Step) which aims to promote weight management skills and the adoption of health-promoting behaviours among overweight adolescents.

Methods
We conducted a randomized clinical trial with a sample of 80 adolescents. The control group followed the standard intervention. The experimental group was invited to access the platform during 12 weeks in addition to the standard intervention.

Results
Although there was no change in the primary outcomes (body mass index and percentage of fat mass), the results suggest that the program is associated with an improvement in the ‘positive perspective of life’ and ‘benefits perceived from the intervention’, which have been identified as relevant factors for an effective weight management.

Conclusions
Our findings provide little support for the effectiveness of internet-based weight management programs as an add-on to the standard intervention.

[Jo Bowyer]

Misleading p-values showing up more often in biomedical journal articles

https://www.sciencedaily.com/release...0315120539.htm

A review of p-values in the biomedical literature from 1990 to 2015 shows that these widely misunderstood statistics are being used increasingly, instead of better metrics of effect size or uncertainty.

[Jo Bowyer]

Healing of rotator cuff tendons using botulinum toxin A and immobilization in a rat model

http://bmcmusculoskeletdisord.biomed...891-016-0978-y

Abstract

Background
We evaluated effects of botulinum toxin A (Botox) and cast immobilization on tendon healing in a rat model. Injection of Botox into rat supraspinatus was hypothesized to reduce muscle active force and improved healing.

Methods
Eighty-four supraspinatus tendons were surgically transected and repaired in 42 Sprague-Dawley rats (transosseous technique). After repair, supraspinatus muscle was injected with saline or Botox (3 or 6 U/kg). Half the shoulders were cast-immobilized for the entire postoperative period; half were allowed free cage activity. Histology was examined at 2, 4, 8, and 12 weeks. A healing zone cross-sectional area was measured, and biomechanical testing of repair strength and tendon viscoelastic properties was conducted at 4 and 12 weeks.

Results
Botox alone and cast immobilization alone exhibited increased ultimate load compared with controls (saline injection, no immobilization) at 4 weeks. No difference in ultimate load occurred between Botox-only and cast-only groups. At 12 weeks, the Botox (6 U/kg) plus cast immobilization group was significantly weakest (p < 0.05). A trend was shown toward decreased healing zone cross-sectional areas in casted groups.

Conclusions
Supraspinatus Botox injection after rotator cuff repair might help protect the repair. However, cast immobilization plus Botox administration is harmful to rotator cuff healing in a rat tendon model.

Keywords

Rotator cuff repair Botulinum toxin A (Botox) Cast immobilization Tendon healing Rat model

[Jo Bowyer]

A valid model for predicting responsible nerve roots in lumbar degenerative disease with diagnostic doubt

http://bmcmusculoskeletdisord.biomed...891-016-0973-3

Abstract

Objective
To construct and validate a model to predict responsible nerve roots in lumbar degenerative disease with diagnostic doubt (DD).

Methods
From January 2009-January 2013, 163 patients with DD were assigned to the construction (n = 106) or validation sample (n = 57) according to different admission times to hospital. Outcome was assessed according to the Japanese Orthopedic Association (JOA) recovery rate as excellent, good, fair, and poor. The first two results were considered as effective clinical outcome (ECO). Baseline patient and clinical characteristics were considered as secondary variables. A multivariate logistic regression model was used to construct a model with the ECO as a dependent variable and other factors as explanatory variables. The odds ratios (ORs) of each risk factor were adjusted and transformed into a scoring system. Area under the curve (AUC) was calculated and validated in both internal and external samples. Moreover, calibration plot and predictive ability of this scoring system were also tested for further validation.

Results
Patients with DD with ECOs in both construction and validation models were around 76 % (76.4 and 75.5 % respectively). Risk factors: more preoperative visual analog pain scale (VAS) score (OR = 1.56, p < 0.01), stenosis levels of L4/5 or L5/S1 (OR = 1.44, p = 0.04), stenosis locations with neuroforamen (OR = 1.95, p = 0.01), neurological deficit (OR = 1.62, p = 0.01), and more VAS improvement of selective nerve route block (SNRB) (OR = 3.42, p = 0.02). Validation: the internal area under the curve (AUC) was 0.85, and the external AUC was 0.72, with a good calibration plot of prediction accuracy. Besides, the predictive ability of ECOs was not different from the actual results (p = 0.532).

Conclusions
We have constructed and validated a predictive model for confirming responsible nerve roots in patients with DD. The associated risk factors were preoperative VAS score, stenosis levels of L4/5 or L5/S1, stenosis locations with neuroforamen, neurological deficit, and VAS improvement of SNRB. A tool such as this is beneficial in the preoperative counseling of patients, shared surgical decision making, and ultimately improving safety in spine surgery.

Keywords

Lumbar degenerative disease Diagnostic doubt Predictive model Selective nerve route block



Most of the peripheral joint and spinal surgeons I know use diagnostic nerve blocks for purposes of clarification.

[Jo Bowyer]

Cost-Effectiveness of Capsaicin 8% Patch Compared with Pregabalin for the Treatment of Patients with Peripheral Neuropathic Pain in Scotland

http://journals.plos.org/plosone/art...l.pone.0150973

Abstract

We evaluated the cost-effectiveness of capsaicin 8% patch (QUTENZA™) versus pregabalin in patients with PNP from the perspective of the National Health Service (NHS) and Personal and Social Services in Scotland, UK. A decision-tree cost-effectiveness model was developed for non-diabetic patients with peripheral neuropathic pain (PNP) who were pregabalin-naïve and had not achieved adequate pain relief or tolerated conventional first- or second-line treatments. Patients entering the model received either a single application of capsaicin 8% patch or titrated daily dosing with pregabalin; after 8 weeks patients were classified as responders, non-responders, or were assumed to discontinue treatment due to intolerable adverse events. Responders continued to receive baseline treatment at intervals observed in clinical practice. Non-responders and those who discontinued treatment were assumed to receive last-line therapy (duloxetine). The base-case time horizon was 2 years. Model inputs for effectiveness, discontinuations and health-state utilities were taken from a head-to-head non-inferiority study (ELEVATE, NCT01713426). Other inputs were obtained from published sources or clinical expert opinion. Costs were expressed in GBP 2013/14. Results were presented as incremental cost-effectiveness ratios (ICER), i.e. cost per quality-adjusted life-year (QALY) gained. Model assumptions were tested with scenario analyses. Parameter uncertainty was tested using one-way and probabilistic sensitivity analyses. Compared with dose-optimized pregabalin, capsaicin 8% patch was the dominant treatment strategy (total cost difference, –£11; total QALY gain, 0.049). Capsaicin 8% patch was also the dominant treatment strategy versus pregabalin in 6 out of 7 scenario analyses. The model was most sensitive to variation in time to capsaicin 8% patch retreatment (maximum ICER, £7,951/QALY at lower-bound 95% confidence interval). At a willingness-to-pay threshold of £20,000/QALY, the probability of capsaicin 8% patch being cost-effective versus pregabalin was 97%. Capsaicin 8% patch is a cost-effective treatment option compared with dose-optimized pregabalin in patients with PNP who have failed one or more previous systemic treatments.

[Jo Bowyer]

In defence of observational science: randomised experiments aren’t the only way to the truth

https://theconversation.com/in-defen...%20the%20truth

Would you volunteer to become vegetarian for the next three decades for the sake of science? What if you were asked to run at least 50 kilometres per week, or live through a natural disaster?

Granted, these are extreme requests. Researchers conducting randomised controlled trials often ask volunteers to make far smaller changes to their behaviour: exercise a bit more, eat less sugar or try a new medication.

During these trials, scientists randomly allocate the medicine, treatment or activity being studied to a group of people, and a different intervention or placebo to another group. Then they look for differences in participant outcomes.

Purists believe experiments like this are the only way to gain valuable knowledge, and popular conception of science is intimately connected to experimentation.

Yet some of the most critical scientific questions we face today can’t be investigated through experiment. For instance, we can’t determine whether greenhouse gas emissions are really causing climate change by not producing them for several decades and recording the results.

Likewise, many important medical questions either can’t or shouldn’t be settled experimentally. A chasm separates the controlled conditions of the laboratory from the messy reality of life. Sometimes, studying participants in real conditions through observational studies is the best way to find answers.

via Simon Gandevia's twitter feed

[Jo Bowyer]

Clinical research is wasted when systematic reviews fail to provide a complete and up-to-date evidence synthesis: Cochrane team proposes a new approach

https://community.cochrane.org/news/...and-up-to-date

An innovative analysis from a team of Cochrane France researchers suggests that systematic reviews of multiple treatments provide a fragmented, out-of-date panorama of the available evidence. These findings question the current approach to synthesizing evidence and suggest that it does not fully address the needs of patients and clinicians.

The article, recently published in BMC Medicine, is co-authored by Perrine Créquit, Ludovic Trinquart, Amélie Yavchitz, and Philippe Ravaud, from Cochrane France and INSERM U1153 METHODS team, Paris, France.

Multiple treatments are now frequently available for the same disease. Patients and physicians need a comprehensive, up-to-date synthesis of evidence for all competing treatments to know which treatments work best. The author team took a specific example - second-line treatments of advanced non-small cell lung cancer and attempted to assess whether such a complete and up-to-date evidence synthesis was available over time.

To carry out this assessment, the authors performed a series of systematic overviews and networks of randomized trials to assess the gap between evidence covered by systematic reviews and available trials. They also propose a new approach to evidence synthesis, called “live cumulative network meta-analysis”, which outlines how to switch from a series of systematic reviews — performed at different points in time, frequently out-of-date, and focusing on specific treatments (many treatments being not considered) – to a single systematic review covering all treatments, with network meta-analyses, and updated continuously to incorporate the results of new trials when they become available.

[Jo Bowyer]

Psychometric properties of the Neck OutcOme Score (NOOS), Neck Disability Index (NDI) and Short form-36 (SF-36) were evaluated in patients with neck pain

http://www.jclinepi.com/article/S089...027-0/abstract

Abstract

Objective
To assess reliability, construct validity, responsiveness and interpretability for Neck OutcOme Score (NOOS), Neck Disability Index (NDI) and Short-form-36 (SF-36) in neck pain patients.

Study Design and setting
Internal consistency was assessed by Cronbach’s alpha. Test-retest reliability was evaluated by intraclass correlation coefficient and measurement error was estimated from the standard error of measurement (SEM). Responsiveness was assessed as standardised response mean (SRM) and interpretability from the minimal important difference (MID). Construct validity was tested correlating subscale scores from NOOS and SF-36 and NDI items.

Results
At baseline 196 neck pain patients were included. Cronbach’s α was adequate for most NOOS subscales, NDI and SF-36 with few exceptions. Good to excellent reliability was found for NOOS subscales (ICC 0.88-0.95), for NDI and for SF-36 with few exceptions. For NOOS minimal detectable changes varied between 1.1-1.9 and construct validity was supported. SRMs were higher for NOOS subscales (0.19 to 0.42), compared to SF-36 and NDI. MID values varied between 15.0 and 24.1 for NOOS subscales.

Conclusions
In conclusion, the NOOS is a reliable, valid and responsive measure of self-reported disability in neck pain patients, performing at least as well or better than the commonly used SF-36 and NDI.

Keywords:
Patient-reported outcome, questionnaire, measurement instrument, neck pain, reliability, construct validity, responsiveness, interpretability

via Simon Gandevia's twitter feed





Self-report and subjective history in the diagnosis of painful neck conditions: A systematic review of diagnostic accuracy studies


http://www.mskscienceandpractice.com...Rehabilitation Abstract

Rising healthcare costs and inherent risks with over-utilizing diagnostic imaging require a quality subjective examination to improve effectiveness and time management of physical examinations. This systematic review investigates the diagnostic accuracy of subjective history and self-report items to determine if there is significant alteration in the probability of identifying specific painful neck conditions.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Inclusion criteria: 1) Written in the English language 2) Cervical pain with/without referred upper extremity or head pain 3) Subjective history or self-report items 4) Study designs that reported diagnostic statistics or allowed calculation of sensitivities, specificities, diagnostic odds ratios, and likelihood ratios 5) used a reference standard that has a sensitivity or specificity ≥75% or a diagnostic tool that is strongly supported in the literature where this data is not available. Quality Assessment of Studies of Diagnostic Accuracy II was performed to evaluate risk of bias.

Five studies with 830 total patients met the inclusion criteria. Conditions commonly reported in the literature included: cervical radiculopathy, cervical myelopathy, degenerative joint disease, and cervicogenic headache.

Individual history questions show minimal diagnostic value in identifying cervical conditions without the physical examination. The value of the subjective history report is important and requires further investigation for specific neck conditions. Clustering symptoms may provide more insight than individual history items in future studies. The diagnostic value of history for neck conditions may be underrepresented due to the lack of studies that isolate subjective examination from the physical examination.

Level of Evidence: 3a Keywords:

Diagnostic accuracy, Self-report, Subjective history, Neck pain





Manual therapy, exercise therapy or combined treatment in the management of adult neck pain – A systematic review and meta-analysis


http://www.mskscienceandpractice.com...Rehabilitation Highlights

• The effects of combining therapies on neck pain and function was assessed.
• No studies investigated the effects of adding exercise therapy to manual therapy.
• Adding manual therapy to exercise therapy does not seem to improve outcomes.
• The quality of evidence was moderate for pain-at-rest outcomes.
• The quality of evidence was moderate-to-low for neck disability and quality of life outcomes.

Abstract

Background


Neck pain is a common and often disabling musculoskeletal condition. Two therapies frequently prescribed for its management are manual therapy (MT) and exercise therapy (ET), and combining these treatment approaches are common.Objective


To assess whether or not combined treatment consisting of MT and ET is more effective than either therapy alone in relieving pain and improving function in adult patients with grade I-II neck pain.Design


Systematic review with meta-analysis.Methods


A systematic search on EMBASE, MEDLINE, AMED, CENTRAL and PEDro were performed until June 2017. Randomized controlled trials with adult grade I-II neck pain patients were included if they investigated the combined effect of MT and ET to the same ET or MT alone, and reported pain intensity or disability on numerical scales. Quality of life was assessed as a secondary outcome. Quality of the included trials was assessed with the PEDro scale, and the quality of evidence was assessed with GRADE.Results


1169 articles were screened, and 7 studies were included, all of which investigated the addition of ET to MT. Only very small and non-significant between group differences was found on pain intensity at rest, neck disability, and quality of life at immediate post-treatment, 6 months, and 12 months follow-up. The quality of evidence was moderate for pain-at-rest outcomes and moderate too low for neck disability and quality of life outcomes.Conclusion


Combined treatment consisting of MT and ET does not seem to be more effective in reducing neck pain intensity at rest, neck disability or improving quality of life in adult patients with grade I-II neck pain, than ET alone.

Keywords:

Neck pain, Combined treatment, Manual therapy, Exercise


Update 05/08/2017

[Jo Bowyer]

BMJ editor Fiona Godlee takes on corruption in science

http://www.cbc.ca/news/health/bmj-fi...ence-1.3541769

It's unusual to watch one of the world's most powerful editors in scientific publishing play with a marionette puppet.

But Dr. Fiona Godlee, editor of the BMJ, specializes in the unexpected.

The puppet she's holding is dressed as a doctor, complete with a stethoscope around its neck. Its strings represent the hidden hand of the pharmaceutical industry.

"I think we have to call it what it is. It is the corruption of the scientific process."

There are increasing concerns these days about scientific misconduct. Hundreds of papers are being pulled from the scientific record, for falsified data, for plagiarism, and for a variety of other reasons that are often never explained.

Sometimes it's an honest mistake. But it's estimated that 70 per cent of the retractions are based on some form of scientific misconduct.

"Medicine and science are run by human beings, so there will always be crooks," Godlee says.

A troubling new way to evade plagiarism detection software. (And how to tell if it’s been used.)

http://retractionwatch.com/2017/04/2...are-tell-used/

Recently, at the end of a tutorial, a student asked Ann Rogerson a question she’d never heard before: Was it okay to use paraphrasing tools to write up assignments? Rogerson, a senior lecturer in the faculty of business at the University of Wollongong in Australia, was stumped — she’d never heard of these tools before.

It turns out, the student had learned of the tool from another student. For an assignment, the student had taken wording from a journal article and run it through a free online tool that automatically paraphrases text, so it evades plagiarism detection software.

Immediately, Rogerson remembered wording from a previous student submission that had always bugged her — in an assignment about employee performance reviews, the student had written awkward phrases such as “constructive employee execution” and “worker execution audits.” A lightbulb went off for Rogerson.

She immediately went to her computer, looked up the tools on Google, and easily found one. She typed in “employee performance reviews,” and the tool spit out “representative execution surveys.”


I had my answer about what the student in the previous session had done.

Update 26/04/2017





How much text recycling is okay?

http://retractionwatch.com/2017/07/0...ecycling-okay/

Update 07/07/2017





“So, here we are! You’ve decided to join the dark side of Science. That’s great!” Ten Simple Rules for Scientific Fraud & Misconduct. (Nicholas Rougier and John Timmer)

https://hal.inria.fr/hal-01562601/document


from Retraction Watch

Update 22/07/2017

[Jo Bowyer]

The Numbers Will Love You Back in Return-I Promise.

http://www.ncbi.nlm.nih.gov/pubmed/2...?dopt=Abstract

Abstract

The first sport-science-oriented and comprehensive paper on magnitude-based inferences (MBI) was published 10 y ago in the first issue of this journal. While debate continues, MBI is today well established in sport science and in other fields, particularly clinical medicine, where practical/clinical significance often takes priority over statistical significance. In this commentary, some reasons why both academics and sport scientists should abandon null-hypothesis significance testing and embrace MBI are reviewed. Apparent limitations and future areas of research are also discussed. The following arguments are presented: P values and, in turn, study conclusions are sample-size dependent, irrespective of the size of the effect; significance does not inform on magnitude of effects, yet magnitude is what matters the most; MBI allows authors to be honest with their sample size and better acknowledge trivial effects; the examination of magnitudes per se helps provide better research questions; MBI can be applied to assess changes in individuals; MBI improves data visualization; and MBI is supported by spreadsheets freely available on the Internet. Finally, recommendations to define the smallest important effect and improve the presentation of standardized effects are presented.

Neuroskeptic calls this "A whimsically-titled paper about p-values and effect sizes " I liked the abstract .

[Jo Bowyer]

Noninvasive monitor assesses patients' response to painful stimulation during surgery

https://www.sciencedaily.com/release...0513112146.htm

"There's currently no standardized, objective method for physicians to monitor the effectiveness of pain relieving drugs being administered during surgery," said Ruth Edry, M.D., lead study author and senior physician anesthesiologist at Rambam Medical Center in Haifa, Israel. "Not effectively monitoring bodily responses to painful stimulation can lead to insufficient amounts of pain medication being administered, which can result in the patient having severe pain upon regaining consciousness from anesthesia, while too much medication may cause other side effects such as nausea and vomiting or respiratory complications."

Under general anesthesia, patients are unconscious, but their body still shows reflex responses to the surgical procedure, including changes in heart rate, blood pressure, eyes tearing or sweating. These unwanted reflexes can in some cases be dangerous, and physician anesthesiologists adjust the amount of anesthesia and pain medication when they occur. The nociception (pain) level index, which uses an algorithmic combination to process multiple hormonal and neurological reactions, aims to provide a better, earlier measure of the body's reflex response to painful stimulation during surgery, compared to the traditional monitoring of individual factors such as changes in heart rate or blood pressure.

[Jo Bowyer]

Absence of Evidence or Evidence of Absence? A commentary on “Captured by the pain: Pain steady-state evoked potentials are not modulated by selective spatial attention.”

http://journal.frontiersin.org/artic...016.00252/full

A broad range of cognitive factors modulates behavioral, and cortical responses to painful stimuli, and pain perception. Among them, attention plays an important role (Wiech et al. 2008). Selective attention to a sensory modality or selective spatial attention to a given body part can modulate the processing of painful stimuli (Legrain et al. 2012; Spence et al., 2002). Painful stimuli also yield the ability to capture involuntary attentional processes depending on their salience and relevance for current goals (Legrain et al. 2012). Yet, previous electrophysiological studies that have assessed the effect of selective attention on pain have mostly used very short and transient stimuli (Legrain et al. 2012). Recently, Blöchl et al. (2015) used steady-state evoked brain potentials (SS-EPs) to investigate the effect of selective spatial attention on the cerebral processing of sustained painful stimuli. SS-EPs reflects a sustained cortical response induced by the periodic modulation of a long-lasting stream of sensory input (Regan, 1989). Using this approach, top-down effects of attention on the cortical processing of intramodal sensory inputs have been demonstrated in visual, auditory, and somatosensory modalities (Bidet-Caulet et al., 2007; Giabbiconi et al., 2004, 2007; Morgan et al., 1996). Typically, selectively attending to one of several concurrently presented streams of sensory inputs increases the magnitude of the SS-EP elicited by the attended stream. Blöchl and collaborators hypothesized that selectively attending to one of two painful inputs applied on the hands would lead to a selective enhancement of the magnitude of the SS-EP elicited by the attended input. Unlike their prediction, they failed to demonstrate such a modulation. They argued that attention cannot be effectively shifted between two simultaneously applied sustained painful stimuli, and that this would constitute a unique property of pain as compared to other senses. Although we understand their interpretation, in our opinion, their results do not fully justify this interpretation.
A first concern is that other studies have failed to demonstrate top-down attentional modulation of SS-EPs elicited by two sensory inputs belonging to the same sensory modality. In a pioneering EEG study, Linden et al. (1987) found no evidence of an attentional modulation of auditory SS-EPs whereas more recent research found an effect and suggested that the attentional modulation may depend on the experimental context (Müller et al. 2009). Attentional modulation of innocuous somatosensory SS-EPs may also depend on the modulation frequency, the task difficulty, or the experimental design (Adler et al. 2009; Katus et al. 2014). Taken together, this suggests that top-down attentional modulation of SS-EPs is highly context-dependent. Therefore, the lack of effect reported by Blöchl and collaborators could result from the specific experimental context of their study, rather than to the fact that the eliciting stimuli were painful.
Accordingly, the modulation frequencies used by Blöchl and collaborators (31 and 37 Hz) are quite different from those usually used to elicit somatosensory SS-EPs. Tobimatsu et al. (1999) found that the optimal frequency range to elicit non-nociceptive somatosensory SS-EPs lies between 20 and 30 Hz with a maximum around 21 Hz. Moreover, attentional modulation of non-nociceptive somatosensory SS-EPs has been mostly reported using modulation frequencies between 20-26 Hz (Giabbiconi et al., 2004, 2007), and intermodal attentional modulation of nociceptive SS-EP has been shown at 6 Hz (Colon et al., 2014). Furthermore, using similar frequencies (30 and 34 Hz) and a simple detection task, Adler et al. (2009) failed to demonstrate attentional modulation of non-nociceptive somatosensory SS-EPs. However, when slightly decreasing the modulation frequencies (28 and 30 Hz) and using a more demanding discriminative task, they observed a significant effect. Consequently, both the modulation frequency and the task may be critical to observe top-down attentional modulation of SS-EPs.
Another methodological difference concerns the timing of the cue that defined the attended stream in Bloch and collaborators. Their cue occurred 3 seconds after the onset of the stimulation trains, whereas in most previous studies in the somatosensory modality, the attended stream was cued 200 to 800 ms before the onset of the stimulation train (Adler et al., 2009; Giabbiconi et al., 2004, 2007). We also demonstrated top-down attentional modulation of concomitant nociceptive and visual SS-EPs only when the onsets of the concomitantly presented stimulation trains were shortly delayed to facilitate the selection of the attended stream (Colon et al., 2014). Therefore, the delayed cue in Bloch and collaborators could have impaired the attentional selection of the attended stream. Moreover, the attentional effect was assessed only during the 2 seconds of stimulation that followed the cue. This time interval might have been too short for an attentional modulation to be highlighted.
A second important concern relates to the functional significance of the painful SS-EPs (PSS-EPs). As highlighted by the authors, it is not clear whether PSS-EPs actually differed from SS-EPs elicited by innocuous somatosensory input. The scalp topographies of their PSS-EPs were significantly lateralized towards the hemisphere contralateral to the stimulated hand, and resembled closely the scalp topographies of innocuous somatosensory SS-EPs (Giabbiconi et al., 2004, 2007). Most importantly, these scalp topographies were clearly different from the non-lateralized fronto-central scalp topography of SS-EPs elicited by periodic nociceptive stimulation (Colon et al., 2012, 2014; Mouraux et al., 2011). Moreover, the concentric electrode used to elicit PSS-EPs has been suggested to activate selectively nociceptive afferents only when very low stimulation intensities are used (de Tommaso et al., 2011; Legrain & Mouraux, 2013; Perchet et al., 2012). In Bloch and collaborators, it is likely that the average intensity of 1.03 mA activated a significant proportion of non-nociceptive somatosensory fibers. Consequently, the PSS-EPs could predominantly reflect activity generated by the activation of non-nociceptive somatosensory afferents.
Therefore, although Blöchl and collaborators present an interesting approach to investigate cortical responses evoked by sustained painful stimulation, we believe that critical factors regarding the used methodology and the functional significance of the SS-EPs elicited by intra-epidermal electrical stimulation should be considered prior to concluding that, unlike other sensations, tonic pain is relatively insensitive to top-down modulation by spatial attention. Yet, uncertainty still abounds regarding the exact parameters required to observe attentional modulation of PSS-EPs.

[Jo Bowyer]

Sharing raw data from clinical trials: what progress since we first asked “Whose data set is it anyway?”

http://trialsjournal.biomedcentral.c...ource=Teradata

Abstract

Ten years ago, one of the first papers published in Trials was a commentary entitled “Whose data set is it anyway?” The commentary pointed out that trialists routinely refused requests for data sharing and argued that this attitude was a community standard that had no rational basis. At the time, there had been few calls for clinical trial data sharing and certainly no institutional support. Today the situation could not be more different. Numerous organizations now recommend or require raw data to be made available, including the International Committee of Medical Journal Editors, which recently proposed that clinical trial data sharing be a “condition of … publication.” Furthermore, the literature is replete with papers covering an enormously wide variety of topics on data sharing. But despite a tectonic shift in attitudes, we are yet to see clinical trial data sharing become an unquestioned norm, where a researcher can readily download a data set from a trial almost as easily as they can now download a copy of the published paper. The battle over the next few years is to go beyond changing minds to ensuring that real data sets are routinely made available.

[Jo Bowyer]

Significant improvements in pain after a six-week physiotherapist-led exercise and education intervention, in patients with osteoarthritis awaiting arthroplasty, in South Africa: a randomised controll

http://bmcmusculoskeletdisord.biomed...891-016-1088-6

Abstract

Background
A major challenge facing those with late stage osteoarthritis is delayed surgery due to waiting lists. In South Africa patients wait years for a hip/knee arthroplasty. Affected patients require effective management to address their pain, especially while awaiting surgery. Existing literature is mostly available from high income countries exploring effects of interventions during short waiting periods. Research is warranted in low income countries where long waiting periods are common. This study explored the effects of a six-week physiotherapist-led exercise and education intervention on pain in this population.

Methods
A randomised controlled trial was performed at two public hospitals in South Africa. Ethical approval and informed consent was obtained. 74 participants from arthroplasty waiting lists were randomly allocated to an intervention (n = 35) or control group (n = 39). The intervention included six physiotherapist-led group-based sessions (two hours/week of education, exercise and relaxation). The control group received usual care. Data collection was conducted by blinded physiotherapists at baseline, week six, 12 and month six. The primary outcome was pain, measured by the Brief Pain Inventory. Additionally, participants completed an open-ended questionnaire at month six, to gain insight regarding the intervention. Analysis was by intention to treat using two-way analysis of variance and post-hoc Tukey comparisons. Answers to subjective questions were analysed according to common themes that emerged.

Results
The intervention group had significant improvements compared with the control group with moderate to large effect sizes (ES) on pain severity [week 6: p < 0.01, ES = 0.94, 95 % CI (0.45,1.41), month 6: p = 0.02. ES = 0.74, 95 % CI (0.26,1.2)] and moderate to large effects on pain interference [week 6: p < 0.01, ES = 1.2, 95 % CI (0.70,1.69), week 12: p = 0.04, ES = 0.68, 95 % CI (0.20,1.14), month 6: p < 0.01, ES = 0.98, 95 % CI (0.49,1.45)]. 53 % of participants reported that the intervention improved their pain.

Conclusions
The intervention resulted in sustained significant improvements in pain severity and interference in patients with hip/knee osteoarthritis, awaiting arthroplasty compared with a control group. Additionally, participants’ individual feedback supported observed significant improvements in pain. Such an intervention appears to be effective in managing pain in this population and should be incorporated into practice for appropriate patients. Further research is being conducted to explore long term and postoperative outcomes.

Clinical trial registration

Keywords

Hip/knee osteoarthritis Arthroplasty/joint replacement Waiting list Physiotherapy Exercise Education Chronic pain

[Jo Bowyer]

The p-Value You Can't Buy.

http://www.ncbi.nlm.nih.gov/pubmed/2...?dopt=Abstract
Abstract

There is growing frustration with the concept of the p-value. Besides having an ambiguous interpretation, the p-value can be made as small as desired by increasing the sample size, n. The p-value is outdated and does not make sense with big data: Everything becomes statistically significant. The root of the problem with the p-value is in the mean comparison. We argue that statistical uncertainty should be measured on the individual, not the group, level. Consequently, standard deviation (SD), not standard error (SE), error bars should be used to graphically present the data on two groups. We introduce a new measure based on the discrimination of individuals/objects from two groups, and call it the D-value. The D-value can be viewed as the n-of-1 p-value because it is computed in the same way as p while letting n equal 1. We show how the D-value is related to discrimination probability and the area above the receiver operating characteristic (ROC) curve. The D-value has a clear interpretation as the proportion of patients who get worse after the treatment, and as such facilitates to weigh up the likelihood of events under different scenarios. [Received January 2015. Revised June 2015.].

KEYWORDS:
Discrimination error; Effect size; ROC curve; Significance testing.

via Mick Thacker's twitter feed