Modest Bias Research Articles

Variation and Trends in the Documentation of National Institutes of Health Stroke Scale in GWTG-Stroke Hospitals.

Although National Institutes of Health Stroke Scale (NIHSS) is an important prognostic variable, it is often incompletely documented in clinical registries, such as Get With The Guidelines (GWTG)-Stroke. We describe trends in NIHSS documentation by GWTG-Stroke hospitals, identify patient-level and hospital-level factors associated with documentation, and determine the degree to which the reporting of NIHSS is potentially biased. We analyzed NIHSS documentation in 1 184 288 patients with acute ischemic stroke admitted to 1704 GWTG-Stroke hospitals between 2003 and 2012. We used multivariable logistic regression models to identify hospital-level and patient-level predictors of NIHSS documentation. We examined the relationship between hospital-level NIHSS documentation rates and observed NIHSS scores to determine whether the reporting of NIHSS data was subject to selection bias. The overall NIHSS documentation rate was 56.1%; the median NIHSS was 4 (interquartile range, 2-9). Between 2003 and 2012, mean hospital-level NIHSS documentation increased dramatically from 27% to 70% (P<0.0001). Documentation was higher in patients who arrived by ambulance, who arrived soon after onset, and were treated at larger, primary stroke centers. Hospital-level NIHSS documentation rates and NIHSS scores were modestly inversely correlated (r=-0.207; P<0.0001), suggesting that NIHSS data from hospitals with low documentation were shifted toward higher values. In sensitivity analysis, the degree of bias in NIHSS reporting was reduced in more recent years (2011-2012) when NIHSS documentation was noticeably better. Documentation of NIHSS is higher in patients who are thrombolysis candidates. Evidence of modest bias in NIHSS scores was observed but this has lessened as the documentation of NIHSS has improved in recent years.

MUC1 Predicts Colorectal Cancer Metastasis: A Systematic Review and Meta-Analysis of Case Controlled Studies.

ObjectiveTo evaluate the predicting value of MUC1 expression in lymph node and distant metastasis of colorectal cancer (CRC).MethodsPubmed/ MEDLINE and EMBASE were searched to identify eligible studies that evaluated the correlation between MUC1 and CRC. A meta-analysis was conducted to evaluate the impact of MUC1 expression on CRC metastasis.ResultsA total of 18 studies (n = 3271) met inclusion criteria and the mean Newcastle-Ottawa Scale (NOS) score was 6.3 with a range from 4 to 8. The pooled OR in the meta-analysis of 15 studies indicated that positive MUC1 expression correlated with more CRC node metastasis (OR = 2.32, 95% CI = 1.63–3.29). The data synthesis of 6 studies suggested that MUC1 expression predicted more possibility of CRC distant metastasis (OR = 2.22, 95% CI = 1.23–4.00). In addition, the combined OR of 7 studies showed that MUC1 expression indicated higher Duke’s stage (OR = 3.02, 95% CI = 2.11–4.33). No publication bias was found in the mate-analysis by Begg’s test or Egger’s test with the exception of the meta-analysis of MUC1 with CRC node metastasis (Begg’s test p = 0.729, Egger’s test p = 0.000).ConclusionsDespite of some modest bias, the pooled evidence suggested that MUC1 expression was significantly correlated with CRC metastasis.

Transfer accuracy of vinyl polysiloxane trays for indirect bonding.

To elicit the magnitude, directional bias, and frequency of bracket positioning errors caused by the transfer of brackets from a dental cast to the patient's dentition in a clinical setting. A total of 136 brackets were evaluated. The brackets were placed on dental casts and scanned using cone beam computed tomography (CBCT) to capture 3-D positioning data. The brackets were then transferred to the patient's dentition with an indirect bonding method using vinyl polysiloxane (VPS) trays and later scanned using CBCT to capture the final bracket positioning on the teeth. Virtual models were constructed from the two sets of scan data and digitally superimposed utilizing best-fit, surface-based registration. Individual bracket positioning differences were quantified using customized software. One-tailed t tests were used to determine whether bracket positioning was within limits of 0.5 mm in the mesiodistal, buccolingual, and vertical dimensions, and 2° for torque, tip, and rotation. Individual bracket positioning differences were not statistically significant, indicating, in general, final bracket positions within the selected limits. Transfer accuracy was lowest for torque (80.15%) and highest for mesiodistal and buccolingual bracket placement (both 98.53%). There was a modest directional bias toward the buccal and gingival. Indirect bonding using VPS trays transfers the planned bracket position from the dental cast to the patient's dentition with generally high positional accuracy.

Laboratory investigation of antenna signals from dust impacts on spacecraft

AbstractWe describe laboratory experiments which reproduce characteristic signals observed on spacecraft, believed to be caused by dust impact. A simulated spacecraft, including an antenna system using a facsimile of the preamplifier electronics from the STEREO/WAVES instrument, was bombarded by 10 km/s submicron‐sized dust at the University of Colorado Institute for Modeling Plasma, Atmospheres, and Cosmic Dust accelerator facility. Signal variation was investigated as a function of the DC potentials of both the spacecraft and the antennas. We observed (1) signals corresponding to modification of the spacecraft body potential, an important process believed to be responsible for the so‐called “triple hit” antenna signals on STEREO, (2) a few‐eV energy distribution for the electrons and ions released in the impact leading to (3) signals corresponding to direct recollection of a substantial fraction of the impact charge by the spacecraft antennas, even at modest antenna bias potentials. We also observe (4) an unexpected class of fast antenna signals, which do not appear to be caused by charge recollection by either the spacecraft or the antennas and may be induced by charge separation in the expanding plasma cloud. Similar signals are also commonly observed by the STEREO/WAVES instrument but have not previously been analyzed.

Neuropathic pain: New analysis sheds light on optimal drug therapy

Finer points Finnerup and colleagues conducted a systematic review and meta-analysis of 229 reports or trials (both published and unpublished) that assessed the use of systemic and topical therapies for the treatment of neuropathic pain. They applied their results to update current practice recommendations released by the Special Interest Group on Neuropathic Pain (NeuPSIG). The investigators noted that most trial outcomes were modest and publication bias may account for a 10% overstatement of treatment effects. On the basis of GRADE recommendations, the analysis showed that there is strong evidence to support the use of tricyclic antidepressants, serotonin–noradrenaline reuptake inhibitors (particularly duloxetine), pregabalin, and gabapentin as rst-line agents for patients with neuropathic pain. Capsaicin 8% patches, lidocaine patches, tramadol, subcutaneous botulinum toxin A, and strong opioids all had weak GRADE recommendations for use based on poorer evidence, high costs, or safety concerns. Both high-concentration capsaicin and lidocaine patches were recommended as second-line agents for peripheral neuropathic pain, and botulinum toxin A as a third-line agent when used by a specialist to manage this condition.

Synergistic ultraviolet photoresponse of a nanostructured ZnO film with gate bias and ultraviolet illumination

We report large enhancement of photoresponse in a nanostructured ZnO film using an electrolyte as a gate dielectric with gate bias and ultraviolet (UV) illumination. The gate bias used for observing the large response is low and ≤5 V. The resultant current enhancement by the combined effect of two effects (field effect and illumination) is much larger than the simple addition of two effects when they act individually. The polymeric electrolyte used as gate dielectric forms an electric double layer at the interface between the nanostructured film and gate dielectric, which enables accumulation of large charge carrier density (≈1013–1014) at the interface. The field effect mobility, μFE, of the carriers is enhanced under modest gate bias in the presence of UV illumination due to the reduction of barrier EB in between the nano crystallites because of large surface charge induced by field effect. It is proposed that the gate induced carriers also passivate the charged defect states in the ZnO, thereby reducing carrier scattering and enhancing the photocurrent. The mechanism proposed has been validated by observation of gate controlled Photoluminescence, where the passivation of charged defect states by gate induced carriers led to suppression of visible photoluminescence, which arises from charged oxygen vacancy defect states.

Rosenberg自尊量表中的方法因素及其相关物

Rosenberg自尊量表的因素结构仍然是学术界争论的焦点问题。本研究拟解决如下问题：量表测量的是单维还是双维结构，中国被试中是否存在正向和反向方法因素，这两种方法因素在多大程度上影响了测验的结构效度和效标关联效度，不同测量工具中的方法因素是否同质，是否可解释为一种稳定的反应风格或人格变量，中国人的自尊量表得分有哪些不同于西方人的独有特征等。对525名大学生被试测试了自尊、大五人格、一般健康等人格量表，结果发现自尊量表中的正向和反向题有相似的心理测量学性能，测量相同特质。正向和反向方法因素在中国被试中都存在，但没有破坏自尊的单维结构。反向方法因素对测验结果的影响更强。不同测量工具中的方法因素具有同质性，属于系统误差，具有高抑郁、高神经质等特征的人容易受方法因素的影响。中国被试在自尊上表现出了谦虚、含蓄，能辩证地认识积极和消极自我等东方文化的特质。 There is an ongoing debate on the use of negatively worded items in Rosenberg Self Esteem Scale (RSES) and other personality measures. This study was designed to explore the following questions: Do the five positively and five negatively worded RSES items measure one factor or two oblique factors? Do negative wording effect and positive wording effect exist in Chinese culture? If the answer is yes, to what extend do they affect structural and criterion related validity of RSES? Do negative and positive wording effect abstracted from different personality measures exhibit congruent validity? Can they be considered response style or meaningful personality variables? What features can be observed in Chinese participants that differentiate them from Western ones? 525 undergraduates were recruited and were administrated RSES, BFI, STAI, CES-D, GHQ-12, IRI, WLEIS, GWB, and MCSD. The results showed: the positively and negatively worded items in RSES perform similar psychometric properties; Method effect can be observed both in positively and negatively worded items, which are detrimental to the construct validity of RSES; When one trait factor and two method factors are defined in CTCM, close model data fit result in; In RSES the size of positive method effect is much smaller than negative method effect; Method effects in RSES and other personality measures are similar in nature; Modest bias is confirmed in the present study, Chinese people show stronger tendency to admit negative aspects of their self-concepts. As a con-clusion, balanced use of positively and negatively worded items is encouraged. Advanced statistic method should be employed to control method factors and estimate the true relationships between constructs measured by different personality measures. Chinese people are dialectical and are more modest when assessing their self-esteem.

THE MUSIC OF CLASH: PREDICTIONS ON THE CONCENTRATION-MASS RELATION

We present the results of a numerical study based on the analysis of the MUSIC-2 simulations, aimed at estimating the expected concentration-mass relation for the CLASH cluster sample. We study nearly 1400 halos simulated at high spatial and mass resolution, which were projected along many lines-of-sight each. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White, the generalised Navarro-Frenk-White, and the Einasto density profiles. We derive concentrations and masses from these fits and investigate their distributions as a function of redshift and halo relaxation. We use the X-ray image simulator X-MAS to produce simulated Chandra observations of the halos and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos which resemble the X-ray morphology of the CLASH clusters is composed mainly by relaxed halos, but it also contains a significant fraction of un-relaxed systems. For such a sample we measure an average 2D concentration which is ~11% higher than found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in 3D for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61. Simulated halos with X-ray morphologies similar to those of the CLASH clusters are affected by a modest orientation bias.

Aerosol microphysics simulations of the Mt.~Pinatubo eruption with the UM-UKCA composition-climate model

Abstract. We use a stratosphere–troposphere composition–climate model with interactive sulfur chemistry and aerosol microphysics, to investigate the effect of the 1991 Mount Pinatubo eruption on stratospheric aerosol properties. Satellite measurements indicate that shortly after the eruption, between 14 and 23 Tg of SO2 (7 to 11.5 Tg of sulfur) was present in the tropical stratosphere. Best estimates of the peak global stratospheric aerosol burden are in the range 19 to 26 Tg, or 3.7 to 6.7 Tg of sulfur assuming a composition of between 59 and 77 % H2SO4. In light of this large uncertainty range, we performed two main simulations with 10 and 20 Tg of SO2 injected into the tropical lower stratosphere. Simulated stratospheric aerosol properties through the 1991 to 1995 period are compared against a range of available satellite and in situ measurements. Stratospheric aerosol optical depth (sAOD) and effective radius from both simulations show good qualitative agreement with the observations, with the timing of peak sAOD and decay timescale matching well with the observations in the tropics and mid-latitudes. However, injecting 20 Tg gives a factor of 2 too high stratospheric aerosol mass burden compared to the satellite data, with consequent strong high biases in simulated sAOD and surface area density, with the 10 Tg injection in much better agreement. Our model cannot explain the large fraction of the injected sulfur that the satellite-derived SO2 and aerosol burdens indicate was removed within the first few months after the eruption. We suggest that either there is an additional alternative loss pathway for the SO2 not included in our model (e.g. via accommodation into ash or ice in the volcanic cloud) or that a larger proportion of the injected sulfur was removed via cross-tropopause transport than in our simulations. We also critically evaluate the simulated evolution of the particle size distribution, comparing in detail to balloon-borne optical particle counter (OPC) measurements from Laramie, Wyoming, USA (41° N). Overall, the model captures remarkably well the complex variations in particle concentration profiles across the different OPC size channels. However, for the 19 to 27 km injection height-range used here, both runs have a modest high bias in the lowermost stratosphere for the finest particles (radii less than 250 nm), and the decay timescale is longer in the model for these particles, with a much later return to background conditions. Also, whereas the 10 Tg run compared best to the satellite measurements, a significant low bias is apparent in the coarser size channels in the volcanically perturbed lower stratosphere. Overall, our results suggest that, with appropriate calibration, aerosol microphysics models are capable of capturing the observed variation in particle size distribution in the stratosphere across both volcanically perturbed and quiescent conditions. Furthermore, additional sensitivity simulations suggest that predictions with the models are robust to uncertainties in sub-grid particle formation and nucleation rates in the stratosphere.

Weak lensing measurements in simulations of radio images

We present a study of weak lensing shear measurements for simulated galaxy images at radio wavelengths. We construct a simulation pipeline into which we can input galaxy images of known shapelet ellipticity, and with which we then simulate observations with eMERLIN and the international LOFAR array. The simulations include the effects of the clean algorithm, uv sampling, observing angle and visibility noise, and produce realistic restored images of the galaxies. We apply a shapelet-based shear measurement method to these images and test our ability to recover the true source shapelet ellipticities. We model and deconvolve the effective point spread function, and find suitable parameters for clean and shapelet decomposition of galaxies. We demonstrate that ellipticities can be measured faithfully in these radio simulations, with no evidence of an additive bias and a modest (10 per cent) multiplicative bias on the ellipticity measurements. Our simulation pipeline can be used to test shear measurement procedures and systematics for the next generation of radio telescopes.

The nebular emission of star-forming galaxies in a hierarchical universe

Galaxy surveys targeting emission lines are characterising the evolution of star-forming galaxies, but there is still little theoretical progress in modelling their physical properties. We predict nebular emission from star-forming galaxies within a cosmological galaxy formation model. Emission lines are computed by combining the semi-analytical model \sag\ with the photoionisation code \mapp. We characterise the interstellar medium (ISM) of galaxies by relating the ionisation parameter of gas in galaxies to their cold gas metallicity, obtaining a reasonable agreement with the observed \ha, \oii, \oiii\ luminosity functions, and the the BPT diagram for local star-forming galaxies. The average ionisation parameter is found to increase towards low star-formation rates and high redshifts, consistent with recent observational results. The predicted link between different emission lines and their associated star-formation rates is studied by presenting scaling relations to relate them. Our model predicts that emission line galaxies have modest clustering bias, and thus reside in dark matter haloes of masses below $M_{\rm halo} \lesssim 10^{12} {[\rm h^{-1} M_{\odot}]}$. Finally, we exploit our modelling technique to predict galaxy number counts up to $z\sim 10$ by targeting far-infrared (FIR) emission lines detectable with submillimetre facilities

Loss to clinic and five-year mortality among HIV-infected antiretroviral therapy initiators.

Missing outcome data due to loss to follow-up occurs frequently in clinical cohort studies of HIV-infected patients. Censoring patients when they become lost can produce inaccurate results if the risk of the outcome among the censored patients differs from the risk of the outcome among patients remaining under observation. We examine whether patients who are considered lost to follow up are at increased risk of mortality compared to those who remain under observation. Patients from the US Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) who newly initiated combination antiretroviral therapy between January 1, 1998 and December 31, 2009 and survived for at least one year were included in the study. Mortality information was available for all participants regardless of continued observation in the CNICS. We compare mortality between patients retained in the cohort and those lost-to-clinic, as commonly defined by a 12-month gap in care. Patients who were considered lost-to-clinic had modestly elevated mortality compared to patients who remained under observation after 5 years (risk ratio (RR): 1.2; 95% CI: 0.9, 1.5). Results were similar after redefining loss-to-clinic as 6 months (RR: 1.0; 95% CI: 0.8, 1.3) or 18 months (RR: 1.2; 95% CI: 0.8, 1.6) without a documented clinic visit. The small increase in mortality associated with becoming lost to clinic suggests that these patients were not lost to care, rather they likely transitioned to care at a facility outside the study. The modestly higher mortality among patients who were lost-to-clinic implies that when we necessarily censor these patients in studies of time-varying exposures, we are likely to incur at most a modest selection bias.

Body mass index and knee osteoarthritis risk: a dose-response meta-analysis.

Evidence shows obesity is an important risk factor for knee osteoarthritis (OA). However, the dose-response relationship between body mass index (BMI) and knee OA risk is unclear. The purpose of the current study is to establish a nonlinear dose-response relationship between BMI and risk of knee OA. The electronic database of PubMed, Web of Science, and translating research into practice (TRIP) database were searched. Observational studies for BMI and knee OA risk were included. Restricted cubic splines and generalized least-squares regression methods were used to model a potential curvilinear relationship and to make a dose-response meta-analysis. A total of 12 studies were included in the meta-analysis. A non-linear dose-response association between BMI and risk of knee OA was significant (P = 0.001). The relative risks were 1.59 (95% CI: 1.34-1.81), 3.55 (95% CI: 2.51-5.11), and 7.45 (95% CI: 4.19-13.13) when BMI was at the point of 25, 30, and 35 kg/m(2) compared with reference (22.5 kg/m(2) , the median value of the lowest category), respectively. Non-linear dose-response association was also significant in male and female subgroup. In male subgroup, the relative risks were 1.39 (95% CI: 0.99-1.92), 3.41 (95% CI: 2.07-5.48), and 5.71 (95% CI: 3.12-9.95) when BMI was at the point of 25, 30, and 32.5 kg/m(2) compared with reference, respectively. In female subgroup, the relative risks were 1.72 (95% CI: 1.51-1.99), 3.51 (95% CI: 2.65-4.51), and 4.72 (95% CI: 3.25-6.91) compared with reference when BMI was at the point of 25, 30, and 32.5 kg/m(2) compared with reference, respectively. Modest publication bias was found in the meta-analysis. However, sensitivity analysis showed a high stability for the result. The meta-analysis indicated that knee OA risk increased almost exponentially according with the increase of body mass index. Knee OA prevention will benefit from weight control.

A Molecular Genetic Assessment of Sex Ratios from Pre-fledged Juvenile and Migrating Adult Common Loons (Gavia immer)

Abstract. We used a polymerase chain reaction (PCR)-based sex identification technique to evaluate the sex ratios of pre-fledged juvenile Common Loons (Gavia immer) from three breeding populations in northern Michigan and northern Wisconsin, and of dead adult Common Loons migrating through Lake Huron. Results of these analyses show that more juvenile males than females fledged from all three breeding populations, although none of these biases differed significantly from parity. The sex ratio of migratory adults was at parity. No parental or territory quality indicators were significantly associated with the sex of chicks fledged from one intensely studied northern Michigan population at Seney National Wildlife Refuge. A significant male bias in adult re-observation of Common Loons banded as juveniles at the wildlife refuge was not solely attributable to the modest male bias recorded at fledging, and thus suggests a pattern of female-biased post-fledging mortality and/or female-biased adult dispersal in Co...

A randomly selected population sample undergoing colonoscopy

To analyse the epidemiology of irritable bowel syndrome (IBS) symptoms in a random sample of the general population and in a subsample consenting to a colonoscopy, and to what extent this introduces symptom selection bias. Overall, 3347 randomly selected Swedish adults aged 18-70 years were mailed the validated Abdominal Symptom Questionnaire (ASQ). Responders (n=2293; 68.5%) were contacted by phone, and 745 consented to a colonoscopy. All nonresponders were contacted by phone; 265 were reached and asked seven key ASQ questions. Colonoscopy participants also completed the Rome II Modular Questionnaire. The prevalence of IBS on the basis of the mailed ASQ (troublesome abdominal pain and bowel disturbance in the past 3 months) was 26.2% [95% confidence interval (CI): 24.4-28.0] among the ASQ responders and 36.6% (95% CI: 33.2-40.1) among the colonoscopy participants (P<0.001). Nonresponders had a lower prevalence of IBS (15.8%; 95% CI: 11.4-20.3, P<0.001) than ASQ responders. Colonoscopy participants were slightly older than noncolonoscoped participants completing the ASQ (P<0.001), but men and women were equally represented and no significant socioeconomic differences were identified. The prevalence of IBS was 14.8% (95% CI: 12.2-17.5) on the basis of the Rome II Modular Questionnaire in colonoscopy participants and 14.5% (95% CI: 11.9-17.2) when visible inflammatory disease was excluded. Of the colonoscopy participants, 31.9% (95% CI: 28.5-35.3) were symptom free. IBS symptoms are common and rarely explained by visible inflammatory disease or cancer. There was a modest selection bias by IBS in participants accepting a screening colonoscopy, but still, one-third were symptom free. Thus, conclusions for the general population can be made from findings in the study cohort.

Back Electron–Hole Recombination in Hematite Photoanodes for Water Splitting

The kinetic competition between electron-hole recombination and water oxidation is a key consideration for the development of efficient photoanodes for solar driven water splitting. In this study, we employed three complementary techniques, transient absorption spectroscopy (TAS), transient photocurrent spectroscopy (TPC), and electrochemical impedance spectroscopy (EIS), to address this issue for one of the most widely studied photoanode systems: nanostructured hematite thin films. For the first time, we show a quantitative agreement between all three techniques. In particular, all three methods show the presence of a recombination process on the 10 ms to 1 s time scale, with the time scale and yield of this loss process being dependent upon applied bias. From comparison of data between these techniques, we are able to assign this recombination phase to recombination of bulk hematite electrons with long-lived holes accumulated at the semiconductor/electrolyte interface. The data from all three techniques are shown to be consistent with a simple kinetic model based on competition between this, bias dependent, recombination pathway and water oxidation by these long-lived holes. Contrary to most existing models, this simple model does not require the consideration of surface states located energetically inside the band gap. These data suggest two distinct roles for the space charge layer developed at the semiconductor/electrolyte interface under anodic bias. Under modest anodic bias (just anodic of flatband), this space charge layer enables the spatial separation of initially generated electrons and holes following photon absorption, generating relatively long-lived holes (milliseconds) at the semiconductor surface. However, under such modest bias conditions, the energetic barrier generated by the space charge layer field is insufficient to prevent the subsequent recombination of these holes with electrons in the semiconductor bulk on a time scale faster than water oxidation. Preventing this back electron-hole recombination requires the application of stronger anodic bias, and is a key reason why the onset potential for photocurrent generation in hematite photoanodes is typically ~500 mV anodic of flat band and therefore needs to be accounted for in electrode design for PEC water splitting.

Using Internally Developed Risk Models to Assess Heterogeneity in Treatment Effects in Clinical Trials

Recent proposals suggest that risk-stratified analyses of clinical trials be routinely performed to better enable tailoring of treatment decisions to individuals. Trial data can be stratified using externally developed risk models (eg, Framingham risk score), but such models are not always available. We sought to determine whether internally developed risk models, developed directly on trial data, introduce bias compared with external models. We simulated a large patient population with known risk factors and outcomes. Clinical trials were then simulated by repeatedly drawing from the patient population assuming a specified relative treatment effect in the experimental arm, which either did or did not vary according to a subject's baseline risk. For each simulated trial, 2 internal risk models were developed on either the control population only (internal controls only) or the whole trial population blinded to treatment (internal whole trial). Bias was estimated for the internal models by comparing treatment effect predictions to predictions from the external model. Under all treatment assumptions, internal models introduced only modest bias compared with external models. The magnitude of these biases was slightly smaller for internal whole trial models than for internal controls only models. Internal whole trial models were also slightly less sensitive to bias introduced by overfitting and less sensitive to falsely identifying the existence of variability in treatment effect across the risk spectrum compared with internal controls only models. Appropriately developed internal models produce relatively unbiased estimates of treatment effect across the spectrum of risk. When estimating treatment effect, internally developed risk models using both treatment arms should, in general, be preferred to models developed on the control population.

General motor function assessment scale – reliability of a Norwegian version

Purpose: The General Motor Function assessment scale (GMF) measures activity-related dependence, pain and insecurity among older people in frail health. The aim of the present study was to translate the GMF into a Norwegian version (N-GMF) and establish its reliability and clinical feasibility. Methods: The procedure used in translating the GMF was a forward and backward process, testing a convenience sample of 30 frail elderly people with it. The intra-rater reliability tests were performed by three physiotherapists, and the inter-reliability test was done by the same three plus nine independent colleagues. The statistical analyses were performed with a pairwise analysis for intra- and inter-rater reliability, using Cronbach’s α, Percentage Agreement (PA), Svensson’s rank transformable method and Cohen’s κ. Results: The Cronbach’s α coefficients for the different subscales of N-GMF were 0.68 for Dependency, 0.73 for Pain and 0.75 for Insecurity. Intra-rater reliability: The variation in the PA for the total score was 40–70% in Dependence, 30–40% in Pain and 30–60% in Insecurity. The Relative Rank Variant (RV) indicated a modest individual bias and an augmented rank-order agreement coefficient ra of 0.96, 0.96 and 0.99, respectively. The variation in the κ statistics was 0.27–0.62 for Dependence, 0.17–0.35 for Pain and 0.13–0.47 for Insecurity. Inter-rater reliability: The PA between different testers in Dependence, Pain and Insecurity was 74%, 89% and 74%, respectively. The augmented rank-order agreement coefficients were: for Dependence ra = 0.97; for Pain, ra = 0.99; and for Insecurity, ra = 0.99. Conclusion: The N-GMF is a fairly reliable instrument for use with frail elderly people, with intra-rater and inter-rater reliability moderate in Dependence and slight to fair in Pain and Insecurity. The clinical usefulness was stressed in regard to its main focus, the frail elderly, and for communication within a multidisciplinary team.Implications for RehabilitationThe Norwegian-General Motor Function Assessment Scale (N-GMF) is a reliable instrument.The N-GMF is an instrument for screening and assessment of activity-related dependence, pain and insecurity in frail older people.The N-GMF may be used as a tool of communication in a multidisciplinary team.

Systematic review and meta-analysis of tumor biomarkers in predicting prognosis in esophageal cancer.

BackgroundEsophageal cancer (EC) is a frequently occurring cancer with poor prognosis despite combined therapeutic strategies. Many biomarkers have been proposed as predictors of adverse events. We sought to assess the prognostic value of biomarkers in predicting the overall survival of esophageal cancer and to help guide personalized cancer treatment to give patients the best chance at remission.MethodsWe conducted a systematic review and meta-analysis of the published literature to summarize evidence for the discriminatory ability of prognostic biomarkers for esophageal cancer. Relevant literature was identified using the PubMed database on April 11, 2012, and conformed to the REMARK criteria. The primary endpoint was overall survival and data were synthesized with hazard ratios (HRs).ResultsWe included 109 studies, exploring 13 different biomarkers, which were subjected to quantitative meta-analysis. Promising markers that emerged for the prediction of overall survival in esophageal squamous cell cancer included VEGF (18 eligible studies, n = 1476, HR = 1.85, 95% CI, 1.55-2.21), cyclin D1 (12 eligible studies, n = 1476, HR = 1.82, 95% CI, 1.50-2.20), Ki-67 (3 eligible studies, n = 308, HR = 1.11, 95% CI, 0.70-1.78) and squamous cell carcinoma antigen (5 eligible studies, n = 700, HR = 1.28, 95% CI, 0.97-1.69); prognostic markers for esophageal adenocarcinoma included COX-2 (2 eligible studies, n = 235, HR = 3.06, 95% CI, 2.01-4.65) and HER-2 (3 eligible studies, n = 291, HR = 2.15, 95% CI, 1.39-3.33); prognostic markers for uncategorized ECs included p21 (9 eligible studies, n = 858, HR = 1.27, 95% CI, 0.75-2.16), p53 (31 eligible studies, n = 2851, HR = 1.34, 95% CI, 1.21-1.48), CRP (8 eligible studies, n = 1382, HR = 2.65, 95% CI, 1.64-4.27) and hemoglobin (5 eligible studies, n = 544, HR = 0.91, 95% CI, 0.83-1.00).ConclusionsAlthough some modest bias cannot be excluded, this review supports the involvement of biomarkers to be associated with EC overall survival.

PLASMA COMPOSITION IN A SIGMOIDAL ANEMONE ACTIVE REGION

Using spectra obtained by the EIS instrument onboard Hinode, we present a detailed spatially resolved abundance map of an active region (AR)-coronal hole (CH) complex that covers an area of 359 arcsec x 485 arcsec. The abundance map provides first ionization potential (FIP) bias levels in various coronal structures within the large EIS field of view. Overall, FIP bias in the small, relatively young AR is 2-3. This modest FIP bias is a consequence of the AR age, its weak heating, and its partial reconnection with the surrounding CH. Plasma with a coronal composition is concentrated at AR loop footpoints, close to where fractionation is believed to take place in the chromosphere. In the AR, we found a moderate positive correlation of FIP bias with nonthermal velocity and magnetic flux density, both of which are also strongest at the AR loop footpoints. Pathways of slightly enhanced FIP bias are traced along some of the loops connecting opposite polarities within the AR. We interpret the traces of enhanced FIP bias along these loops to be the beginning of fractionated plasma mixing in the loops. Low FIP bias in a sigmoidal channel above the AR's main polarity inversion line where ongoing flux cancellation is taking place, provides new evidence of a bald patch magnetic topology of a sigmoid/flux rope configfiuration.