Current practice in methodology and reporting of the sample size calculation in randomised trials of hip and knee osteoarthritis: a protocol for a systematic review

Background A key aspect of the design of randomised controlled trials (RCTs) is determining the sample size. It is important that the trial sample size is appropriately calculated. The required sample size will differ by clinical area, for instance, due to the prevalence of the condition and the choice of primary outcome. Additionally, it will depend upon the choice of target difference assumed in the calculation. Focussing upon the hip and knee osteoarthritis population, this study aims to systematically review how the trial size was determined for trials of osteoarthritis, on what basis, and how well these aspects are reported. Methods Several electronic databases (Medline, Cochrane library, CINAHL, EMBASE, PsycINFO, PEDro and AMED) will be searched to identify articles on RCTs of hip and knee osteoarthritis published in 2016. Articles will be screened for eligibility and data extracted independently by two reviewers. Data will be extracted on study characteristics (design, population, intervention and control treatments), primary outcome, chosen sample size and justification, parameters used to calculate the sample size (including treatment effect in control arm, level of variability in primary outcome, loss to follow-up rates). Data will be summarised across the studies using appropriate summary statistics (e.g. n and %, median and interquartile range). The proportion of studies which report each key component of the sample size calculation will be presented. The reproducibility of the sample size calculation will be tested. Discussion The findings of this systematic review will summarise the current practice for sample size calculation in trials of hip and knee osteoarthritis. It will also provide evidence on the completeness of the reporting of the sample size calculation, reproducibility of the chosen sample size and the basis for the values used in the calculation. Trial registration As this review was not eligible to be registered on PROSPERO, the summary information was uploaded to Figshare to make it publicly accessible in order to avoid unnecessary duplication amongst other benefits (https://doi.org/10.6084/m9.figshare.5009027.v1); Registered January 17, 2017

Solitons in Five Dimensional Minimal Supergravity: Local Charge, Exotic Ergoregions, and Violations of the BPS Bound

We describe a number of striking features of a class of smooth solitons in gauged and ungauged minimal supergravity in five dimensions. The solitons are globally asymptotically flat or asymptotically AdS without any Kaluza-Klein directions but contain a minimal sphere formed when a cycle pinches off in the interior of the spacetime. The solutions carry a local magnetic charge and many have rather unusual ergosurfaces. Perhaps most strikingly, many of the solitons have more electric charge or, in the asymptotically AdS case, more electric charge and angular momentum than is allowed by the usual BPS bound. We comment on, but do not resolve, the new puzzle this raises for AdS/CFT.Comment: 60 pages, 12 figures, 3 table

What do we really know about the appropriateness of radiation emitting imaging for low back pain in primary and emergency care? A systematic review and meta-analysis of medical record reviews

Background Since 2000, guidelines have been consistent in recommending when diagnostic imaging for low back pain should be obtained to ensure patient safety and reduce unnecessary tests. This systematic review and meta-analysis was conducted to determine the pooled proportion of CT and x-ray imaging of the lumbar spine that were considered appropriate in primary and emergency care. Methods Pubmed, CINAHL, The Cochrane Database of Systematic Reviews and Embase were searched for synonyms of “low back pain”, “guidelines”, and “adherence” that were published after 2000. Titles, abstracts, and full texts were reviewed for inclusion with forward and backward tracking on included studies. Included studies had data extracted and synthesized. Risk of bias was performed on all studies, and GRADE was performed on included studies that provided data on CT and x-ray separately. A random effect, single proportion meta-analysis model was used. Results Six studies were included in the descriptive synthesis, and 5 studies included in the meta-analysis. Five of the 6 studies assessed appropriateness of x-rays; two of the six studies assessed appropriateness of CTs. The pooled estimate for appropriateness of x-rays was 43% (95% CI: 30%, 56%) and the pooled estimate for appropriateness of CTs was 54% (95% CI: 51%, 58%). Studies did not report adequate information to fulfill the RECORD checklist (reporting guidelines for research using observational data). Risk of bias was high in 4 studies, moderate in one, and low in one. GRADE for x-ray appropriateness was low-quality and for CT appropriateness was very-low-quality. Conclusion While this study determined a pooled proportion of appropriateness for both x-ray and CT imaging for low back pain, there is limited confidence in these numbers due to the downgrading of the evidence using GRADE. Further research on this topic is needed to inform our understanding of x-ray and CT appropriateness in order to improve healthcare systems and decrease patient harms

Scalability of quantum computation with addressable optical lattices

We make a detailed analysis of error mechanisms, gate fidelity, and scalability of proposals for quantum computation with neutral atoms in addressable (large lattice constant) optical lattices. We have identified possible limits to the size of quantum computations, arising in 3D optical lattices from current limitations on the ability to perform single qubit gates in parallel and in 2D lattices from constraints on laser power. Our results suggest that 3D arrays as large as 100 x 100 x 100 sites (i.e., $\sim 10^6$ qubits) may be achievable, provided two-qubit gates can be performed with sufficiently high precision and degree of parallelizability. Parallelizability of long range interaction-based two-qubit gates is qualitatively compared to that of collisional gates. Different methods of performing single qubit gates are compared, and a lower bound of $1 \times 10^{-5}$ is determined on the error rate for the error mechanisms affecting $^{133}$Cs in a blue-detuned lattice with Raman transition-based single qubit gates, given reasonable limits on experimental parameters.Comment: 17 pages, 5 figures. Accepted for publication in Physical Review

Problems persist in reporting of methods and results for the WOMAC measure in hip and knee osteoarthritis trials

Purpose The Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a commonly used outcome measure for osteoarthritis. There are different versions of the WOMAC (Likert, visual analogue or numeric scales). A previous review of trials published before 2010 found poor reporting and inconsistency in how the WOMAC was used. This review explores whether these problems persist. Methods This systematic review included randomised trials of hip and/or knee osteoarthritis published in 2016 that used the WOMAC. Data were extracted on the version used, score range, analysis and results of the WOMAC, and whether these details were clearly reported. Results This review included 62 trials and 41 reported the WOMAC total score. The version used and item range for the WOMAC total score were unclear in 44% (n = 18/41) and 24% (n = 10/41) of trials, respectively. The smallest total score range was 0–10 (calculated by averaging 24 items scored 0–10); the largest was 0–2400 (calculated by summing 24 items scored 0–100). All trials reported the statistical analysis methods but only 29% reported the between-group mean difference and 95% confidence interval. Conclusion Details on the use and scoring of the WOMAC were often not reported. We recommend that trials report the version of the WOMAC and the score range used. The between-group treatment effect and corresponding confidence interval should be reported. If all the items of the WOMAC are collected, the total score and individual subscale scores should be presented. Better reporting would facilitate the interpretation, comparison and synthesis of the WOMAC score in trials

Assessing physiotherapists’ communication skills for promoting patient autonomy for self-management: reliability and validity of the communication evaluation in rehabilitation tool

Purpose: To assess the inter-rater reliability and concurrent validity of the Communication Evaluation in Rehabilitation Tool, which aims to externally assess physiotherapists competency in using Self-Determination Theory-based communication strategies in practice. Materials and methods: Audio recordings of initial consultations between 24 physiotherapists and 24 patients with chronic low back pain in four hospitals in Ireland were obtained as part of a larger randomised controlled trial. Three raters, all of whom had Ph.Ds in psychology and expertise in motivation and physical activity, independently listened to the 24 audio recordings and completed the 18-item Communication Evaluation in Rehabilitation Tool. Inter-rater reliability between all three raters was assessed using intraclass correlation coefficients. Concurrent validity was assessed using Pearson’s r correlations with a reference standard, the Health Care Climate Questionnaire. Results: The total score for the Communication Evaluation in Rehabilitation Tool is an average of all 18 items. Total scores demonstrated good inter-rater reliability (Intraclass Correlation Coefficient (ICC)?=?0.8) and concurrent validity with the Health Care Climate Questionnaire total score (range: r?=?0.7–0.88). Item-level scores of the Communication Evaluation in Rehabilitation Tool identified five items that need improvement. Conclusion: Results provide preliminary evidence to support future use and testing of the Communication Evaluation in Rehabilitation Tool.Implications for RehabilitationPromoting patient autonomy is a learned skill and while interventions exist to train clinicians in these skills there are no tools to assess how well clinicians use these skills when interacting with a patient. The lack of robust assessment has severe implications regarding both the fidelity of clinician training packages and resulting outcomes for promoting patient autonomy.This study has developed a novel measurement tool Communication Evaluation in Rehabilitation Tool and a comprehensive user manual to assess how well health care providers use autonomy-supportive communication strategies in real world-clinical settings.This tool has demonstrated good inter-rater reliability and concurrent validity in its initial testing phase.The Communication Evaluation in Rehabilitation Tool can be used in future studies to assess autonomy-supportive communication and undergo further measurement property testing as per our recommendations

States of Negative Energy and AdS5×S5/ZkAdS_5 \times S_5/Z_k

We develop a careful definition of energy for nonsupersymmetric warped product asymptotically $AdS_d \times M_q$ solutions which include a nonzero p-form. In the case of an electric p-form extending along all the AdS directions, and in particular in the case of self-dual fields like those used in the Freund-Rubin construction, the Hamiltonian is well defined only if a particular asymptotic gauge for the p-form is used. Rather surprisingly, asymptotically this gauge is time dependent, despite the fact the field and metric are not. We then consider a freely orbifolded $AdS_5 \times S_5$ and demonstrate that the standard boundary conditions allow states of arbitrarily negative energy. The states consist of time symmetric initial data describing bubbles that are regular up to singularities due to smeared D3-branes. We discuss the evolution of this data and point out that if the usual boundary conditions are enforced such bubbles may never reach infinity.Comment: 33 pages, 1 figure, v2: minor corrections, added referenc

Charged-rotating black holes and black strings in higher dimensional Einstein-Maxwell theory with a positive cosmological constant

We present arguments for the existence of charged, rotating black holes in $d=2N+1$ dimensions, with $d\geq 5$ with a positive cosmological constant. These solutions posses both, a regular horizon and a cosmological horizon of spherical topology and have $N$ equal-magnitude angular momenta. They approach asymptotically the de Sitter spacetime background. The counterpart equations for $d=2N+2$ are investigated, by assuming that the fields are independant of the extra dimension $y$, leading to black strings solutions. These solutions are regular at the event horizon. The asymptotic form of the metric is not the de Sitter form and exhibit a naked singularity at finite proper distance.Comment: 21 pages, 9 figure

New stable phase of non uniform black strings in AdSd{AdS}_d

We consider the non uniform $AdS$ black string equations in arbitrary number of dimension in a perturbative approach up to order 2 and in a non perturbative. We restrict the study in the perturbative approach to the backreacting modes, since they provide the first relevant corrections on the thermodynamical quantities of the solutions. We also present some preliminary results in the construction of non-perturbative solutions, in particular, we present a first part of the non uniform - uniform black string phase diagram. Our results suggests the existence of a new stable phase for $AdS$ non uniform black strings, namely long non uniform black string, with the extra direction length of the order of the $AdS$ curvature.Comment: Results extended. 14 pages, 5 figure