Address inaccuracy in health registration data: determinants and impacts

Access to demographic data that are complete, accurate and up-to-date is fundamental to many aspects of public health, government and academic work and for accurate interpretation of other databases. Health registration data are the prime source of demographic information for health and social care systems; for example, as an indicator of need, as a source of denominators to convert number of events into rates, or in the case of the residential address information as the basis for generating the call-recall invitation letters that are used for most screening programs (e.g. breast, colo-rectal and AAA screening). However, list inflation (ghosts, duplicates or emigrants) and a degree of address inaccuracy are recognised caveats with the health registration data and a recent NILS-related study on breast screening suggests that improved address accuracy might be a fast and efficient means of increasing screening uptake rates in cities and amongst deprived populations. In NI these data are collated by the BSO who uniquely in the UK also have access to data relating to prescribing, dental registrations and use of A&E services. These can be used to supplement the standard demographic and address information by (i) indicating patients who are alive and resident in NI and (ii) providing an independent source of probably improved address information. This study will use the NI Unique Property Reference Number (UPRN), rather than the addresses per se which are difficult to work with, to compare the addresses registered in the BSO with those addresses in the enumerated 2011 census. Assuming that the census is a more accurate source of address information for individuals, a comparison of the health registration addresses with those recorded at the census, the aim of the proposed study will be to (i) characterise the amount and distributions of these differences, (ii) to see what proportion of those who do not attend for screening did not actually receive an invitation letter because the addresses were incorrect, (iii) to determine how much of the social gradient (and urban/rural differences) in screening uptake are due to address inaccuracies, (iv) a comparison of timing of address changes at the BSO will provide information on the delays in updating of addresses.

Predicting community responses to perturbations in the face of imperfect knowledge and network complexity

How best to predict the effects of perturbations to ecological communities has been a long-standing goal for both applied and basic ecology. This quest has recently been revived by new empirical data, new analysis methods, and increased computing speed, with the promise that ecologically important insights may be obtainable from a limited knowledge of community interactions. We use empirically based and simulated networks of varying size and connectance to assess two limitations to predicting perturbation responses in multispecies communities: (1) the inaccuracy by which species interaction strengths are empirically quantified and (2) the indeterminacy of species responses due to indirect effects associated with network size and structure. We find that even modest levels of species richness and connectance (similar to 25 pairwise interactions) impose high requirements for interaction strength estimates because system indeterminacy rapidly overwhelms predictive insights. Nevertheless, even poorly estimated interaction strengths provide greater average predictive certainty than an approach that uses only the sign of each interaction. Our simulations provide guidance in dealing with the trade-offs involved in maximizing the utility of network approaches for predicting dynamics in multispecies communities.

THE EFFECTS OF 3 NON-ANTIBIOTIC, ANTIMICROBIAL AGENTS ON THE SURFACE HYDROPHOBICITY OF CERTAIN MICROORGANISMS EVALUATED BY DIFFERENT METHODS

The effects of three non-antibiotic, antimicrobial agents (taurolidine, chlorhexidine acetate and providone-iodine) on the surface hydrophobicity of the clinical strains Escherichia coli, Staphylococcus saprophyticus, Staphylococcus epidermidis and Candida albicans were examined. Three recognized techniques for hydrophobicity measurements, Bacterial Adherence to Hydrocarbons (BATH), the Salt Aggregation Test (SAT) and Hydrophobic Interaction Chromatography (HIC) were compared. At concentrations reported to interfere with microbial-epithelial cell adherence, all three agents altered the cell surface hydrophobicity. However, these effects failed to exhibit a uniform relationship. Generally, taurolidine and povidone-iodine treatments decreased the hydrophobicity of the strains examined whereas chlorhexidine acetate effects depended upon the micro-organism treated. Subsequently, the exact contribution of altered cell surface hydrophobicity to the reported microbial anti-adherence effects is unclear. Comparison of the three techniques revealed a better correlation between the results obtained with the BATH test and HIC than the results obtained with the BATH and SAT or SAT and HIC. However, these differences may be due to the inaccuracy associated with the visual assessment of results employed by the SAT.

Thermal Deformation Analysis of Micro satellite Structure

Mounting accuracy of satellite payload and ADCS (attitude determination and control subsystem) seats is one of the requirements to achieve the satellite mission with acceptable performance. Components of mounting inaccuracy are technological inaccuracies, residual plastic deformations after loading (during transportation and orbital insertion), elastic deformations, and thermal deformations during orbital operation. This paper focuses on estimation of thermal deformations of satellite structure. Thermal analysis is executed by applying finite-difference method (IDEAS) and temperature profile for satellite components case is evaluated. Then, Perform thermal finite-element analysis applying the finite-difference model results as boundary conditions; and calculate the resultant thermal strain. Next, applying the resultant thermal strain, perform finite-element structure analysis to evaluate structure deformations at the payload and ADCS equipments seats.

A curvilinear approach to the kinetic analysis of linoleate peroxidation in aqueous liposomes by 2,2'azobis(2-amidoinopropane) dihydrochloride

Lipid peroxidation is a common feature of many chemical and biological processes, and is governed by a complex kinetic scheme. A fundamental stage in kinetic investigations of lipid peroxidation is the accurate determination of the rate of peroxidation, which in many instances is heavily reliant on the method of finite differences. Such numerical approximations of the first derivative are commonly employed in commercially available software, despite suffering from considerable inaccuracy due to rounding and truncation errors. As a simple solution to this, we applied three empirical sigmoid functions (viz. the Prout-Tompkins, Richards & Gompertz functions) to data obtained from the AAPH-mediated peroxidation of aqueous linoleate liposomes in the presence of increasing concentrations of Trolox, evaluating the curve fitting parameters using the widely available Microsoft Excel Solver add-in. We have demonstrated that the five-parameter Richards' function provides an excellent model for this peroxidation, and when applied to the determination of fundamental rate constants, produces results in keeping with those available in the literature. Overall, we present a series of equations, derived from the Richards' function, which enables direct evaluation of the kinetic measures of peroxidation. This procedure has applicability not only to investigations of lipid peroxidation, but to any system exhibiting sigmoid kinetics.

Asynchrony between the Greenland ice core chronology and the radiocarbon calibration curve? Evidence from Irish bogs

A significant cold event, deduced from the Greenland ice cores, took place between 8200 and 8000 cal. BP. Modeling of the event suggests that higher northern latitudes would have also experienced considerable decreases in precipitation and that Ireland would have witnessed one of the greatest depressions. However, no well-dated proxy record exists from the British Isles to test the model results. Here we present independent evidence for a phase of major pine recruitment on Irish bogs at around 8150 cal. BP. Dendrochronological dating of subfossil trees from three sites reveal synchronicity in germination across the region, indicative of a regional forcing, and allows for high-precision radiocarbon based dating. The inner-rings of 40% of all samples from the north of Ireland dating to the period 8500-7500 cal. BP fall within a 25-yr window. The concurrent colonization of pine on peatland is interpreted as drier conditions in the region and provides the first substantive proxy data in support of a significant hydrological change in the north of Ireland accompanying the 8.2 ka event. The dating uncertainties associated with the Irish pine record and the Greenland Ice Core Chronology 2005 (GICC05) do not allow for any overlap between the two. Our results indicate that the discrepancy could be an artifact of dating inaccuracy, and support a similar claim by Lohne et al. (2013) for the Younger Dryas boundaries. If real, this asynchrony will most likely have affected interpretations of previous proxy alignments.

Hydroclimatic changes during the 8.2 ka event revealed by Irish pines

A pivotal cold event, deduced from the Greenland ice cores, took place between 8200 and 8000 cal. BP. Modelling of this climatic episode suggests that higher northern latitudes would have also experienced substantial reduction in rainfall and that Ireland would have observed a notable decline. No well-dated proxy record exists from the British Isles to test the model results. We present significant independent data for a phase of increased Scots pine initiation on Irish bogs at around 8150 cal. BP. Dendrochronological dating of sub-fossil Scots pine trees from three locations reveals synchronicity in germination across the area, indicative of a regional forcing, and allows for high-precision radiocarbon based dates. The starting rings of 40% of all samples from the north of Ireland dating to the period 8500-7500 cal. BP fall within a period of 25 years. The present colonisation model of Scots pine on peatland is interpreted as increasing drier conditions in the region and provides the first meaningful proxy data in support of a significant hydrological change in the north of Ireland accompanying the 8.2 ka event. The dating uncertainties associated with the Irish Scots pine record and the Greenland Ice Core Chronology 2005 (GICC05) do not allow for any overlap between the two. The results indicate that the discrepancy could be a result of dating inaccuracy that could have affected analysis of prior proxy alignments.

TARGETED BIOMETRIC IMPERSONATION

When applying biometric algorithms to forensic verification, false acceptance and false rejection can mean a failure to identify a criminal, or worse, lead to the prosecution of individuals for crimes they did not commit. It is therefore critical that biometric evaluations be performed as accurately as possible to determine their legitimacy as a forensic tool. This paper argues that, for forensic verification scenarios, traditional performance measures are insufficiently accurate. This inaccuracy occurs because existing verification evaluations implicitly assume that an imposter claiming a false identity would claim a random identity rather than consciously selecting a target to impersonate. In addition to describing this new vulnerability, the paper describes a novel Targeted.. FAR metric that combines the traditional False Acceptance Rate (FAR) measure with a term that indicates how performance degrades with the number of potential targets. The paper includes an evaluation of the effects of targeted impersonation on an existing academic face verification system. This evaluation reveals that even with a relatively small number of targets false acceptance rates can increase significantly, making the analysed biometric systems unreliable.

Accuracy of rural refractionists in western China

Purpose. We assessed the prevalence and predictors of inaccurate refractive error among rural refractionists in western China. Methods. A subset of primary school children with visual acuity (VA) ≤6/12 in ≥1 eye, undergoing subjective refinement by local refractionists after cycloplegic autorefraction in an ongoing population-based study, received repeat refraction by university optometrists for quality control. Results. Among 502 children (mean age 10.5 years, 53.2% girls), independent predictors of poor (inaccurate by ≥1.0 diopter [D]) refraction by 21 rural practitioners (66.7% with high school or lower education) included hyperopia (odds ratio [OR], 4.2; 95% confidence interval [CI], 2.4-7.3, P < 0.001), astigmatism (OR = 3.8; 95% CI, 2.5-5.6; P < 0.001) and VA uncorrectable to >6/12 by the rural refractionist (OR = 4.7; 95% CI, 3.1-7.3; P = < 0.001). Among 201 children whose vision was uncorrectable in ≥1 eye by the rural refractionists, vision could be improved to >6/12 by the university optometrist in 110 (54.7%). We estimate vision could be so improved in 9.1% of all children refracted by these rural refractionists. A reason for inaccuracy in this setting is the erroneous tendency of rural refractionists to adjust instrument values for accommodation, even under cycloplegia. Conclusions. Rural refractionists in western China have little formal training and frequently fail to optimize VA among children, even when autorefractors are used. Training is needed emphasizing better use of automated refraction, particularly in children with astigmatism and hyperopia. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Visual morbidity due to inaccurate spectacles among school children in rural China: the See Well to Learn Well Project, report 1.

PURPOSE: Inadequately corrected refractive error is the leading cause of visual disability among children in China; inaccurate spectacles are a potential cause. The prevalence and visual impact of spectacle inaccuracy were studied among rural, secondary-school children, to determine the optimal timing for updating of refraction. METHODS: A random sample of children from years 1 and 2 in all junior and senior high schools in Fuyang Township, Guangdong Province, underwent ocular examination. All children who reported wearing glasses received cycloplegic refraction, vision assessment, and measurement of current spectacles. RESULTS: Among 3226 examined children, 733 (22.7%) reported owning spectacles. Refractive error and spectacle power were assessed for 588 (80.2%) children. They had a mean age of 15.0 +/- 1.6 years; 70.2% were girls, 83.3% had more than -1.5 D of myopia, and 17.9% had presenting vision < or = 6/12 in the better eye. The glasses of 48.8% of children were inaccurate by > or = 1 D; inaccuracy was > or = 2 D in 17.7%. Children with inaccurate glasses (> or = 1 D) had presenting vision in the better eye significantly (P < 0.001) worse than that of children with accurate glasses, and 30.3% had presenting acuity < or = 6/12. In multivariate models, younger age (P = 0.004), more myopic refractive error (P < 0.001), and having glasses > or = 1 year old (P = 0.04) were associated with inaccurate spectacles. DISCUSSION: Inaccurate spectacles are common and are associated with significant visual impairment among children in rural China. Reducing outdated glasses could lessen the visual burden, although refractive services may have to be offered on an annual basis for optimal benefit.

The child self-refraction study results from urban Chinese children in Guangzhou

OBJECTIVE: To compare visual and refractive outcomes between self-refracting spectacles (Adaptive Eyecare, Ltd, Oxford, UK), noncycloplegic autorefraction, and cycloplegic subjective refraction. DESIGN: Cross-sectional study. PARTICIPANTS: Chinese school-children aged 12 to 17 years. METHODS: Children with uncorrected visual acuity ≤ 6/12 in either eye underwent measurement of the logarithm of the minimum angle of resolution visual acuity, habitual correction, self-refraction without cycloplegia, autorefraction with and without cycloplegia, and subjective refraction with cycloplegia. MAIN OUTCOME MEASURES: Proportion of children achieving corrected visual acuity ≥ 6/7.5 with each modality; difference in spherical equivalent refractive error between each of the modalities and cycloplegic subjective refractive error. RESULTS: Among 556 eligible children of consenting parents, 554 (99.6%) completed self-refraction (mean age, 13.8 years; 59.7% girls; 54.0% currently wearing glasses). The proportion of children with visual acuity ≥ 6/7.5 in the better eye with habitual correction, self-refraction, noncycloplegic autorefraction, and cycloplegic subjective refraction were 34.8%, 92.4%, 99.5% and 99.8%, respectively (self-refraction versus cycloplegic subjective refraction, P<0.001). The mean difference between cycloplegic subjective refraction and noncycloplegic autorefraction (which was more myopic) was significant (-0.328 diopter [D]; Wilcoxon signed-rank test P<0.001), whereas cycloplegic subjective refraction and self-refraction did not differ significantly (-0.009 D; Wilcoxon signed-rank test P = 0.33). Spherical equivalent differed by ≥ 1.0 D in either direction from cycloplegic subjective refraction more frequently among right eyes for self-refraction (11.2%) than noncycloplegic autorefraction (6.0%; P = 0.002). Self-refraction power that differed by ≥ 1.0 D from cycloplegic subjective refractive error (11.2%) was significantly associated with presenting without spectacles (P = 0.011) and with greater absolute power of both spherical (P = 0.025) and cylindrical (P = 0.022) refractive error. CONCLUSIONS: Self-refraction seems to be less prone to accommodative inaccuracy than noncycloplegic autorefraction, another modality appropriate for use in areas where access to eye care providers is limited. Visual results seem to be comparable. Greater cylindrical power is associated with less accurate results; the adjustable glasses used in this study cannot correct astigmatism. Further studies of the practical applications of this modality are warranted. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

A comparison of immunohistochemical assays and FISH in detecting the ALK translocation in diagnostic histological and cytological lung tumor material.

Introduction: Detection of the ALK rearrangement in a solid tumor gives these patients the option of crizotinib as an oral form of anticancer treatment. The current test of choice is fluorescence in situ hybridization (FISH), but various cheaper and more convenient immunohistochemical (IHC) assays have been proposed as alternatives. 
Methods: Fifteen FISH-positive cases from patients, seven with data on crizotinib therapy and clinical response, were evaluated for the presence of ALK protein using three different commercially available antibodies: D5F3, using the proprietary automated system (Ventana), ALK1 (Dako), and 5A4 (Abcam). A further 14 FISH-negative and three uncertain (<15% rearrangement detected) cases were also retrieved. Of the total 32 specimens, 17 were excisions and 15 were computed tomography-guided biopsies or cytological specimens. All three antibodies were applied to all cases. Antibodies were semiquantitatively scored on intensity, and the proportion of malignant cells stained was documented. Cutoffs were set by receiver operating curve analysis for positivity to optimize correct classification. 
Results: All three IHC assays were 100% specific but sensitivity did vary: D5F3 86%, ALK 79%, 5A4 71%. Intensity was the most discriminating measure overall, with a combination of proportion and intensity not improving the test. No FISH-negative IHC-positive cases were seen. Two FISH-positive cases were negative with all three IHC assays. One of these had been treated with crizotinib and had failed to show clinical response. The other harbored a second driving mutation in the EGFR gene.
Conclusions: IHC with all three antibodies is especially highly specific (100%) although variably sensitive (71%-86%), specifically in cases with scanty material. D5F3 assay was most sensitive in these latter cases. Occasional cases are IHC-positive but FISH-negative, suggesting either inaccuracy of one assay or occasional tumors with ALK rearrangement that do not express high levels of ALK protein.

Assessment of turbulence model predictions for a centrifugal compressor simulation

Steady-state computational fluid dynamics (CFD) simulations are an essential tool in the design process of centrifugal compressors. Whilst global parameters, such as pressure ratio and efficiency, can be predicted with reasonable accuracy, the accurate prediction of detailed compressor flow fields is a much more significant challenge. Much of the inaccuracy is associated with the incorrect selection of turbulence model. The need for a quick turnaround in simulations during the design optimisation process, also demands that the turbulence model selected be robust and numerically stable with short simulation times.
In order to assess the accuracy of a number of turbulence model predictions, the current study used an exemplar open CFD test case, the centrifugal compressor ‘Radiver’, to compare the results of three eddy viscosity models and two Reynolds stress type models. The turbulence models investigated in this study were (i) Spalart-Allmaras (SA) model, (ii) the Shear Stress Transport (SST) model, (iii) a modification to the SST model denoted the SST-curvature correction (SST-CC), (iv) Reynolds stress model of Speziale, Sarkar and Gatski (RSM-SSG), and (v) the turbulence frequency formulated Reynolds stress model (RSM-ω). Each was found to be in good agreement with the experiments (below 2% discrepancy), with respect to total-to-total parameters at three different operating conditions. However, for the off-design conditions, local flow field differences were observed between the models, with the SA model showing particularly poor prediction of local flow structures. The SST-CC showed better prediction of curved rotating flows in the impeller. The RSM-ω was better for the wake and separated flow in the diffuser. The SST model showed reasonably stable, robust and time efficient capability to predict global and local flow features.