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This paper describes the result of carrying out such a maximisation of a social welfare function prescribed for a model of the United Kingdom economy over the period 1957-66. The choice of social welfare function was a crucial part of the exercise and is discussed in some detail. Optimisation of the welfare function was achieved using modern control theory.[1] The next section of this paper describes the model; its dynamic properties are then evaluated in a subsequent section. Next, the optimisation goal is presented in terms of the model, and a social welfare function is chosen. The optimisation procedure is then applied and the results obtained are presented and discussed. Finally, consideration is given to the ways in which the procedures might in later research be modified as a result of the lessons learnt from this experiment. The results presented in this paper have shown that this model gives a good picture of how controls influence the economic system, despite the restrictions placed upon its size. The major cycles of the fitting period were reproduced and the model's poor ability at forecasting was a direct result of the primitive assumption of a fixed exchange rate. One advantage of its structure was that, apart from the control variables, it had only two exogenous variables. Although there was no quantitative way of assessing the dynamic properties of the model, the results of the dynamic multiplier tests were qualitatively satisfactory. On the other hand the attempt to use a control algorithm in order to suggest a policy which might have given better economic results at the end of 1961 must be admitted to have been a failure. The procedure correctly reflected the instructions given to it in the form of the social welfare function which was selected, but this function treated public and consumers' expenditure as perfect substitutes and omitted to take account of the desirability of certain items and overstated the undesirability of certain oth... [ABSTRACT FROM AUTHOR]

In his treatise on International Trade, Professor Pearce has concluded that no general principles enable us to predict on a priori grounds what the individual gains or losses accruing to the participants on forming a customs union may be (Pearce [14, p. 223]). Yet it is just such a calculation of the gains or losses which constitute the economic rationale for such a union. "In these circumstances", Pearce argues, "there is little point in producing more and more complicated algebra … empirical studies are urgently awaited" (Pearce, op. cit.). In a similar vein, Professor Swann has written, "whether they (i.e. customs unions) are good or bad depends upon the particular circumstances "and "… there is no substitute for measurement in deciding the actual results of a union" (Swann [20, p. 35]). To see what light neoclassical trade theory may throw on the issue, this paper presents calculations of such gains and losses in a static trade model designed with particular reference to the accession of the United Kingdom to the European Economic Community (referred to as EC for short). As set out in detail in the next section, the model consists of four "countries", UK, EC, the Commonwealth (CW) and the rest of the world (RW), eight final commodities (two per country) and two factors per country. Fixed factor endowments are assumed, consumers maximize utility and producers maximize profits. While factors are mobile within a country, they are not mobile between countries, even when the UK joins the EC, and it is assumed that UK accession to the EC has no effects on the technology in any country. [ABSTRACT FROM AUTHOR]

The article examines the results from the numerical analysis literature and reports the results of tests undertaken on five large scale macroeconometric models which were available on the Economic and Social Research Council Macroeconomic Modeling Bureau User Service in 1984 in Great Britain. It presents algorithms that are simple to implement yet produce computational savings of up to 35 percent per solution. The study describes the convergence characteristics of iterative techniques for solving econometric models.

This paper applies an algorithm for the solution of partial current information in rational expectation models to the quarterly Liverpool macroeconomic model of the U.K. The algorithm is shown to produce marginally superior results in forecasts both in ex-post and ex-ante forecasts and can be viewed as an additional tool for the forecaster's kit-bag. [ABSTRACT FROM AUTHOR]

Anderson Gray McKendrick's 1926 paper, 'Applications of mathematics to medical problems', was the earliest reference cited in Dempster et al.'s 1977 paper that defined and popularized the EM algorithm. McKendrick's paper was prominently featured by Joseph Oscar Irwin in his 1962 inaugural address as the President of the Royal Statistical Society (in the UK), entitled 'The place of mathematics in medical and biological statistics'. The link of McKendrick's work to the EM algorithm is due to an improvement made by Irwin on a novel method McKendrick used for estimating an infection rate when the observed data do not distinguish between those individuals who are not susceptible to the infection and those who are susceptible, but do not develop symptoms. This article examines this link, along the way illustrating the central ideas underlying the EM algorithm as well as its properties; the examination also suggests a profiling strategy for speeding up EM, which may be worthy of general investigation. McKendrick's data on an epidemic of cholera are used for illustration and to compare EM with Irwin's method as well as the Newton-Raphson algorithm. Issues beyond computation are also discussed whenever appropriate. [ABSTRACT FROM AUTHOR]

Electoral analysis using aggregate data relies on the availability of accurate voting statistics. One vital piece of information, often missing from official electoral returns, particularly British local government elections, is the total number of valid ballot papers. This figure is essential for the calculation of electoral turnout. When voters have a single vote and official information about the number of ballot papers issued is missing, a figure for the total vote can still be derived. However, local elections in Britain frequently use a system of multiple-member wards, where voters have as many votes as there are seats to be filled. In such cases, calculating the total vote and, hence, the turnout does present a real problem. It cannot be assumed that all voters will use their full quota of votes or that voters will cast a ballot in favour of a single party. This paper develops and tests diff erent algorithms for calculating the total vote in such circumstances. We conclude that the accuracy of an algorithm is closely related to the structure of party competition. The findings of this paper have a number of important implications. First, the difficulties in calculating the turnout in multiple-member wards are identified. This will inform the debate about public participation in the local electoral process. Second, the method for deriving a figure for the total vote has an important bearing on a number of other statistics widely employed in electoral analysis. [ABSTRACT FROM AUTHOR]

A division test involving both context and bare problems was taken by year 5 pupils in 10 different schools at two points in the school year to identify changes in approach as the standard algorithm was introduced. Increase in the use of the standard algorithm led to many errors and only half of the attempts to use this strategy in the second test were successful. More successful were efficient informal strategies although difficulties in structuring a written record of such strategies were evident. Overall 52% of pupils gained a higher score in the second test while 48% remained the same or performed less well. In comparing context and bare problems, development of a successful strategy was most marked in problems that were given a context. In both tests girls performed better than boys with better improvements over the two tests. [ABSTRACT FROM AUTHOR]

Background Studies on ethnic variations in health have played an important role in aetiological and health services research. Most routine datasets, however, do not include information on ethnicity. South Asians, one of the largest minority ethnic groups in Britain, have distinctive names that also allow differentiation of the main sub‐groups with their important differences in health‐related exposures and disease risks [ABSTRACT FROM PUBLISHER]

A layered approach for identifying communities in the Web is presented and explored by applying the flake exact community identification algorithm to the UK academic Web. Although community or topic identification is a common task in information retrieval, a new perspective is developed by: the application of alternative document models, shifting the focus from individual pages to aggregated collections based upon Web directories, domains and entire sites; the removal of internal site links; and the adaptation of a new fast algorithm to allow fully-automated community identification using all possible single starting points. The overall topology of the graphs in the three least-aggregated layers was first investigated and found to include a large number of isolated points but, surprisingly, with most of the remainder being in one huge connected component, exact proportions varying by layer. The community identification process then found that the number of communities far exceeded the number of topological components, indicating that community identification is a potentially useful technique, even with random starting points. Both the number and size of communities identified was dependent on the parameter of the algorithm, with very different results being obtained in each case. In conclusion, the UK academic Web is embedded with layers of non-trivial communities and, if it is not unique in this, then there is the promise of improved results for information retrieval algorithms that can exploit this additional structure, and the application of the technique directly to partially automate Web metrics tasks such as that of finding all pages related to a given subject hosted by a single country's universities. [ABSTRACT FROM AUTHOR]

GARCH models are commonly used as latent processes in econometrics, financial economics, and macroeconomics. Yet no exact likelihood analysis of these models has been provided so far. In this paper we outline the issues and suggest a Markov chain Monte Carlo algorithm which allows the calculation of a classical estimator via the simulated EM algorithm or a Bayesian solution in O(T) computational operations, where T denotes the sample size. We assess the performance of our proposed algorithm in the context of both artificial examples and an empirical application to 26 UK sectorial stock returns, and compare it to existing approximate solutions. [ABSTRACT FROM AUTHOR]

Multi-reservoir operation planning is a complex task involving many variables, objectives, and decisions. This paper applies a hybrid method using genetic algorithm (GA) and linear programming (LP) developed by the authors to determine operational decisions for a reservoir system over the optimization period. This method identifies part of the decision variables called cost reduction factors (CRFs) by GA and operational variables by LP. CRFs are introduced into the formulation to discourage reservoir depletion in the initial stages of the planning period. These factors are useful parameters that can be employed to determine operational decisions such as optimal releases and imports, in response to future inflow predictions. A part of the Roadford Water Supply System, UK, is used to demonstrate the performance of the GA-LP method in comparison to the RELAX algorithm. The proposed approach obtains comparable results ensuring non zero final storages in the larger reservoirs of the Roadford Hydrosystem. It shows potential for generating operating policy in the form of hegging rules without a priori imposition of their form. [ABSTRACT FROM AUTHOR]

Background: Femoral shaft stress fractures in athletes are not common but pose a great diagnostic challenge to clinicians. Because of few clinical signs, diagnosis and treatment are often delayed. Furthermore, if not treated correctly, these fractures are well known for complications and difficulties. Objective: To develop a well structured and reproducible treatment algorithm for athletes with femoral shaft stress fractures. Methods: The proposed algorithm is carried out in four phases, each lasting three weeks, and the move to the next phase is based on the result of the tests carried out at the end of the previous phase. Over nine years, we treated seven top level athletes, aged 17–21. In all athletes, diagnosis was based on physical examination, plain radiographs, and bone scan. Results: As a result of the treatment method, all the athletes were fully engaged in athletic activity 12–18 weeks after the beginning of treatment. After completion of the treatment, the athletes were followed up for 48–96 months. During the follow up, there was no recurrence of discomfort or pain, and all the athletes eventually returned to competition level. Conclusion: These results and data available from the literature suggest that the algorithm is the optimal treatment protocol for femoral shaft stress fractures in athletes, avoiding the common complications and difficulties. [ABSTRACT FROM AUTHOR]

This paper presents a subgroup discovery algorithm APRIORI-SD, developed by adapting association rule learning to subgroup discovery. The paper contributes to subgroup discovery, to a better understanding of the weighted covering algorithm, and the properties of the weighted relative accuracy heuristic by analyzing their performance in the ROC space. An experimental comparison with rule learners CN2, RIPPER, and APRIORI-C on UCI data sets demonstrates that APRIORI-SD produces substantially smaller rulesets, where individual rules have higher coverage and significance. APRIORI-SD is also compared to subgroup discovery algorithms CN2-SD and SubgroupMiner. The comparisons performed on U.K. traffic accident data show that APRIORI-SD is a competitive subgroup discovery algorithm. [ABSTRACT FROM AUTHOR]

A consensus process has been developed to assist the UK National Confidential Enquiry into Patient Outcome and Death in identifying questions to be addressed in its studies. The process utilises the knowledge and experience of a panel of experts via a facilitated brainstorming exercise and employs a robust voting system to produce a list of candidate questions ordered in terms of the preferences expressed by individual panel members. The process which is described has been used successfully to assist the design of two national studies and it is anticipated that the process will be adopted for many studies in the future. [ABSTRACT FROM AUTHOR]

Mathematics can be perceived as being a difficult subject to learn due to the conceptual leaps required to understand particular mathematical topics. In some areas of mathematics, part of the difficulty may be associated with applying sufficient imagination to visualize a particular mathematical concept, and applying sufficient visio-spatial abilities to apply the concept to practical use. In this paper we examine the potential use of animation as an aid for the teaching of mathematical concepts at undergraduate level. An experiment was conducted with a group of UK undergraduate computing students to ascertain if and how animation can potentially be used to support the teaching of mathematical concepts in areas such as rotational symmetry and matrices. In general, the results of the experiment appeared to indicate that animated learning materials can prove more useful than static representations for such topics. [ABSTRACT FROM AUTHOR]

We present an approach to the construction of clusters of life course trajectories and use it to obtain ideal types of trajectories that can be interpreted and analysed meaningfully. We represent life courses as sequences on a monthly timescale and apply optimal matching analysis to compute dissimilarities between individuals. We introduce a new divisive clustering algorithm which has features that are in common with both Ward's agglomerative algorithm and classification and regression trees. We analyse British Household Panel Survey data on the employment and family trajectories of women. Our method produces clusters of sequences for which it is straightforward to determine who belongs to each cluster, making it easier to interpret the relative importance of life course factors in distinguishing subgroups of the population. Moreover our method gives guidance on selecting the number of clusters. [ABSTRACT FROM AUTHOR]

As part of the Vertical Offshore Reference Frames (VORF) project sponsored by the U. K. Hydrographic Office, a new model for Sea Surface Topography (SST) around the British Isles has been developed. For offshore areas (greater than 30 km from the coast), this model is largely derived from satellite altimetry. However, its accuracy and level of detail have been enhanced in coastal areas by the inclusion of not only the 60 PSMSL tide gauges with long-term records around the coasts of the United Kingdom and Ireland but also some 385 gauges established at different epochs and for different observation spans by the U. K. Admiralty. All tide gauge data were brought into a common reference frame by a combination of datum models and direct GPS observations, but a more significant challenge was to bring all short-term sea level observations to an unbiased value at a common epoch. This was achieved through developing a spatial-temporal correlation model for the variations in mean sea level around the British Isles, which in turn meant that gauges with long-term observation spans could be used as control points to improve the accuracy of Admiralty gauges. It is demonstrated that the latter can contribute point observations of mean sea level (MSL) with a precision of 0.078 m. A combination of least squares collocation and interpolation was developed to merge the coastal point and offshore gridded data sets, with particular algorithms having to be developed for different configurations of coastal topology. The resulting model of sea surface topography is shown to present a smooth transition from inshore coastal areas to offshore zones. Further benefits of the techniques developed include an enhanced methodology for detecting datum discontinuities at permanent tide gauges. [ABSTRACT FROM AUTHOR]

We describe instrumental variable (IV) methods for the estimation of the 'dose'-response effects of psychological interventions in randomized controlled trials in which there is variability in the patients' adherence to the allocated therapy (that is, variability in the actual number of sessions of therapy attended) and also variability in the strength of the therapeutic alliance between patients and their therapists. The effect of the therapy on outcome is assumed to be a function of both the number of sessions attended and the strength of the therapeutic alliance, with no intervention effects in the absence of any sessions attended (an exclusion restriction) and the effect of the strength of the alliance being represented by a multiplicative term (interaction) in the treatment-effect model. The IV methods that are described allow for: (a) hidden confounding between sessions, alliance and outcome; (b) measurement errors in the alliance; and (c) that alliance is only measured in those receiving treatment. Three two-stage estimation procedures are illustrated, and their equivalence demonstrated, through Monte Carlo simulation and analysis of the results of an actual trial. [ABSTRACT FROM AUTHOR]

Aripiprazole has recently received approval for the treatment of moderate to severe manic episodes in bipolar I disorder and prevention of new manic episodes in aripiprazole-responsive patients. Aripiprazole differs from other antipsychotics in its pharmacology, and the need for prescribing guidance in the UK was recently identified. A UK multidisciplinary panel was convened in November 2007. This report describes the consensus agreed during the meeting on the optimal approach to prescribing aripiprazole: how best to approach initiation of, and switching to, treatment with aripiprazole and management strategies for side effects. A literature review of the randomised controlled clinical trials of aripiprazole in mania supports these recommendations. Aripiprazole should be initiated at 15 mg/day (range 5-20 mg/day). If necessary, adjunctive medication should be used in early treatment to manage side effects or assist in management of symptoms such as agitation. When switching to aripiprazole, the therapeutic dose of current treatment should be maintained while adding aripiprazole 15 (5-20) mg/day. Only once an effective dose of aripiprazole is reached should previous medication be reduced. Nausea, insomnia and agitation typically resolve within days. Some principles for dosing and switching are provided to assist with a successful treatment outcome with aripiprazole in mania. [ABSTRACT FROM AUTHOR]

Background UK primary care records are computerised and these records are used for both research and quality improvement. However, there is disparity in the prevalence of diabetes found in epidemiological studies compared with that reported through the UK's national quality improvement scheme. Objective To investigate how non-diagnostic computer data could be used to identify, confirm or refute prevalent cases of people with diabetes. Method We carried out a literature review to identify the most accurate non-diagnostic markers. For each type of diabetes we focused on four broad areas; demographic details, biochemical markers, clinical features and therapeutic strategies. Sample markers were tested by calculating their positive predictive value (PPV) and sensitivity (Sn) and their ability to differentiate between types of diabetes. Results Biochemical markers were useful in identifying cases of diabetes but not in differentiating between types of diabetes as the same plasma glucose criterion is used to diagnose Type 1, Type 2, and 'other' types of diabetes; the lack of a 'fasting' qualifier blunts the use of this marker. Auto-immune markers were the most accurate in identifying Type 1 diabetes but are not recorded frequently in primary care. Clinical features of diabetes and therapeutic strategies were of some use - however, without time sequence data are difficult to interpret. Raised plasma glucose (PG), and glycated haemoglobin (HbA1c), had useful PPV but low Sn. When PG was more than 7.0 and less than 11.1 mmol/l, PPV equalled 77.8% and Sn 48%; and when PG was 11.1, PPV equalled 92% and Sn 17%. For an HbA1c of more than 6.5%, PPV was 89% and Sn 73.3%, and for anHbA1c of more than 8, PPV was 92% and Sn 26%. A person with a combination of aged under 30 years and prescribed insulin has an 84% PPV of Type 1 diabetes; if they also have a BMI <30 kg/m2 the PPV increases to 88%. A person age over 45 years and with a BMI >30 kg/m2 has a 5.3% PPV of Type 2 diabetes; if they are also hypertensive the PPV is 30%; Asian ethnicity increases PPV to 44%. Conclusion Non-diagnostic data has the potential to confirm or refute the diagnosis of diabetes and identify its type. [ABSTRACT FROM AUTHOR]

Collections of suitably chosen borehole profiles can be used to infer large-scale trends in ground-surface temperature (GST) histories for the past few hundred years. These reconstructions are based on a large database of carefully selected borehole temperature measurements from around the globe. Since non-climatic thermal influences are difficult to identify, representative temperature histories are derived by averaging individual reconstructions to minimize the influence of these perturbing factors. This may lead to three potentially important drawbacks: the net signal of non-climatic factors may not be zero, meaning that the average does not reflect the best estimate of past climate; the averaging over large areas restricts the useful amount of more local climate change information available; and the inversion methods used to reconstruct the past temperatures at each site must be mathematically identical and are therefore not necessarily best suited to all data sets. In this work, we avoid these issues by using a Bayesian partition model (BPM), which is computed using a trans-dimensional form of a Markov chain Monte Carlo algorithm. This then allows the number and spatial distribution of different GST histories to be inferred from a given set of borehole data by partitioning the geographical area into discrete partitions. Profiles that are heavily influenced by non-climatic factors will be partitioned separately. Conversely, profiles with climatic information, which is consistent with neighbouring profiles, will then be inferred to lie in the same partition. The geographical extent of these partitions then leads to information on the regional extent of the climatic signal. In this study, three case studies are described using synthetic and real data. The first demonstrates that the Bayesian partition model method is able to correctly partition a suite of synthetic profiles according to the inferred GST history. In the second, more realistic case, a series of temperature profiles are calculated using surface air temperatures of a global climate model simulation. In the final case, 23 real boreholes from the United Kingdom, previously used for climatic reconstructions, are examined and the results compared with a local instrumental temperature series and the previous estimate derived from the same borehole data. The results indicate that the majority (17) of the 23 boreholes are unsuitable for climatic reconstruction purposes, at least without including other thermal processes in the forward model. [ABSTRACT FROM AUTHOR]

Background: We aimed to estimate and externally validate a new UK-specific prognostic model for predicting the long-term risk of a first recurrent event (local recurrence, metastatic recurrence, or second primary breast cancer) in women diagnosed with early breast cancer.Methods: Using data on the prognostic characteristics and outcomes of 1844 women treated for early breast cancer at the Churchill Hospital in Oxford, parametric regression-based survival analysis was used to estimate a prognostic model for recurrence-free survival. The model, which incorporated established prognostic factors, was externally validated using independent data. Its performance was compared with that of the Nottingham Prognostic Index (NPI) and Adjuvant! Online.Results: The number of positive axillary lymph nodes, tumour grade, tumour size and patient age were strong predictors of recurrence. Oestrogen receptor (ER) positivity was shown to afford a moderate protective effect. The model was able to separate patients into distinct prognostic groups, and predicted well at the patient level, mean Brier Accuracy Score=0.17 (s.e.=0.004) and overall C=0.745 (95% CI, 0.717-0.773). Its performance diminished only slightly when applied to a second independent data set. When compared with the NPI, the model was able to better discriminate between women with excellent and good prognoses, and it did not overestimate 10-year recurrence-free survival to the extent observed for Adjuvant! Online.Conclusion: The model estimated here predicts well at both the individual patient and group levels, and appears transportable to patients treated at other UK hospitals. Its parametric form permits long-term extrapolation giving it an advantage over other prognostic tools currently in use. A simple point scoring system and reference table allow 5-, 10-, and 15-year predictions from the model to be quickly and easily estimated. The model is also available to download as an interactive computer program. [ABSTRACT FROM AUTHOR]

This paper proposes an algorithm that uses forecast encompassing tests for combining forecasts when there are a large number of forecasts that might enter the combination. The algorithm excludes a forecast from the combination if it is encompassed by another forecast. To assess the usefulness of this approach, an extensive empirical analysis is undertaken using a US macroeconomic dataset. The results are encouraging; the algorithm forecasts outperform benchmark model forecasts, in a mean square error (MSE) sense, in a majority of cases. The paper also compares the empirical performance of different approaches to forecast combination, and provides a rule-of-thumb cut-off point for the thick-modeling approach. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The central question in mechanism design is how to implement a given social choice function. One of the most studied concepts is that of truthful implementations in which truth-telling is always the best response of the players. The Revelation Principle says that one can focus on truthful implementations without loss of generality (if there is no truthful implementation then there is no implementation at all). Green and Laffont (Rev Econ Stud 53:447-456, 1986) showed that, in the scenario in which players' responses can be partially verified, the revelation principle holds only in some particular cases. When the Revelation Principle does not hold, non-truthful implementations become interesting since they might be the only way to implement a social choice function of interest. In this work we show that, although non-truthful implementations may exist, they are hard to find. Namely, it is NP-complete to decide if a given social choice function can be implemented in a non-truthful manner, or even if it can be implemented at all. This is in contrast to the fact that truthful implementability can be efficiently recognized, even when partial verification of the agents is allowed. Our results also show that there is no 'simple' characterization of those social choice functions for which it is worth looking for non-truthful implementations. [ABSTRACT FROM AUTHOR]

Background: The United Kingdom NHS Breast Screening Programme was established in 1988, and women aged between 50 and 70 are routinely invited at three yearly intervals. Expected United Kingdom interval cancer rates have been calculated previously, but this is the first publication from an exercise to collate individual-based interval cancer data at a national level.Methods: Interval cancer case ascertainment is achieved by the regular exchange of data between Regional Breast Screening Quality Assurance Reference Centres and Cancer Registries. The present analysis includes interval cancers identified in women screened between 1st April 1997 and 31st March 2003, who were aged between 50 and 64 at the time of their last routine screen.Results: In the periods >0-<12 months, 12-<24 months and 24-<36 months after a negative screen, we found overall interval cancer rates and regional ranges of 0.55 (0.43-0.76), 1.13 (0.92-1.47) and 1.22 (0.93-1.57) per 1000 women screened, respectively. Rates in the period 33-<36 months showed a decline, possibly associated with early re-screening or delayed presentation.Conclusions: Interval cancer rates were higher than the expected rates in the 24-month period after a negative screen, but were similar to published results from other countries. Increases in background incidence may mean that the expected rates are underestimated. It is also possible that, as a result of incomplete case ascertainment, interval cancers rates were underestimated in some regions in which rates were less than the expected. [ABSTRACT FROM AUTHOR]

Summary: We examined the effect of glucocorticoid dose on FRAX® derived fracture probabilities in a UK setting. A relatively simple adjustment of conventional FRAX estimates of probabilities of hip fracture and a major osteoporotic fracture can be applied to modulate the risk assessment with knowledge of the dose of glucocorticoids. Introduction: The WHO fracture risk assessment (FRAX) tool estimates 10-year probability of fracture based upon multiple clinical risk factors and an optional femoral neck BMD measurement. Ever (past and current) use of systemic glucocorticoids is a dichotomous risk factor (yes/no) and does not therefore take account of the dose of glucocorticoids. The aim of this work was to estimate the adjustment for fracture probability based upon the dose of glucocorticoids. Methods: Dose responses for fracture risk during exposure to glucocorticoids were taken from the General Practice Research Database and used to adjust the relative risks for glucocorticoids in FRAX. In addition to fracture risk, a dose response for the death hazard was estimated and both variables were used to populate the FRAX model for the UK. Results: The exposure to glucocorticoids was found to significantly affect fracture probability. The following rule was formulated. For low-dose exposure (<2.5 mg daily of prednisolone or equivalent), the probability of a major fracture is decreased by about 20% depending on age. For medium doses (2.5-7.5 mg daily), the unadjusted FRAX value can be used. For high doses (>7.5 mg daily), probabilities can be upward revised by about 15%. Conversion factors were also determined for the adjustment of hip fracture probability. Conclusion: A relatively simple adjustment of conventional FRAX estimates of probabilities of hip fracture and a major osteoporotic fracture can be applied to modulate the risk assessment with knowledge of the dose of glucocorticoids. [ABSTRACT FROM AUTHOR]

BackgroundThere are no risk models for the prediction of anxiety that may help in prevention. We aimed to develop a risk algorithm for the onset of generalized anxiety and panic syndromes.MethodFamily practice attendees were recruited between April 2003 and February 2005 and followed over 24 months in the UK, Spain, Portugal and Slovenia (Europe4 countries) and over 6 months in The Netherlands, Estonia and Chile. Our main outcome was generalized anxiety and panic syndromes as measured by the Patient Health Questionnaire. We entered 38 variables into a risk model using stepwise logistic regression in Europe4 data, corrected for over-fitting and tested it in The Netherlands, Estonia and Chile.ResultsThere were 4905 attendees in Europe4, 1094 in Estonia, 1221 in The Netherlands and 2825 in Chile. In the algorithm four variables were fixed characteristics (sex, age, lifetime depression screen, family history of psychological difficulties); three current status (Short Form 12 physical health subscale and mental health subscale scores, and unsupported difficulties in paid and/or unpaid work); one concerned country; and one time of follow-up. The overall C-index in Europe4 was 0.752 [95% confidence interval (CI) 0.724–0.780]. The effect size for difference in predicted log odds between developing and not developing anxiety was 0.972 (95% CI 0.837–1.107). The validation of predictA resulted in C-indices of 0.731 (95% CI 0.654–0.809) in Estonia, 0.811 (95% CI 0.736–0.886) in The Netherlands and 0.707 (95% CI 0.671–0.742) in Chile.ConclusionsPredictA accurately predicts the risk of anxiety syndromes. The algorithm is strikingly similar to the predictD algorithm for major depression, suggesting considerable overlap in the concepts of anxiety and depression. [ABSTRACT FROM PUBLISHER]

We investigate the effect of target familiarity on the construction of facial composites, as used by law enforcement to locate criminal suspects. Two popular software construction methods were investigated. Participants were showna target face that was either familiar or unfamiliar to them and constructed a composite of it from memoryusing a typical ‘feature’ system, involving selection of individual facial features, or one of the newer ‘holistic’ types, involving repeated selection and breeding from arrays of whole faces. This study found that composites constructed of a familiar face were named more successfully than composites of an unfamiliar face; also, naming of composites of internal and external features was equivalent for construction of unfamiliar targets, but internal features were better named than the external features for familiar targets. These findings applied to both systems, althoughbenefit emerged for the holistic type due to more accurate construction of internal features and evidence for a whole-face advantage. Statement of Relevance: This work is of relevance to practitioners who construct facial composites with witnesses to and victims of crime, as well as for software designers to help them improve the effectiveness of their composite systems. [ABSTRACT FROM AUTHOR]

Five years of UK Met Office global model analyses from 1 January 2004 to 31 December 2008 have been used to generate a global hail climatology at 1° latitude by 1° longitude resolution. Hail has been diagnosed from model vertical profiles of temperature and humidity using a simple algorithm based on a paper by Fawbush and Miller (). Results have been compared with published observational climatologies on both a global and regional basis. The model diagnoses compare favourably with the observed data with both orographic and seasonal signals. However, there are differences, and possible reasons for these are discussed. These include limitations of the simple algorithm, the difficulty of observing hail in sparsely populated areas and the problem of population growth influencing the number of hail reports. Copyright © 2011 Royal Meteorological Society and Crown Copyright [ABSTRACT FROM AUTHOR]

People who are disabled with multiple sclerosis (MS) may be at increased risk of osteoporosis. This review discusses issues relevant to bone health in MS and makes practical recommendations regarding prevention and screening for osteoporosis and fracture risk in MS. A search of the literature up until 5 April 2011 was performed using key search terms, and articles pertinent to bone health in MS were analysed. Bone mineral density (BMD) is reduced at the lumbar spine, hip and total body in MS, with the degree of reduction being greatest at the hip. A strong relationship exists between the disability level, measured by the Expanded Disability Status Score, and BMD at the lumbar spine and femoral neck, particularly the latter. The rate of loss of BMD also correlates with the level of disability. Pulsed corticosteroids for acute episodes of MS, even with a high cumulative steroid dose, do not significantly affect BMD, but an effect on fracture risk is yet to be elucidated. There appears to be no correlation between vitamin D levels and BMD, and the relationship between disability and vitamin D levels remains unclear. Falls and fractures are more common than in healthy controls, and the risk rises with increasing levels of disability. The principal factor resulting in low BMD and increased fracture risk in MS is immobility. Antiresorptive therapy with bisphosphonates and optimising vitamin D levels are likely to be effective interventions although there are no randomised studies of this therapy. [ABSTRACT FROM AUTHOR]

This study proposes an imperialist competition algorithm (ICA) to maximise the benefits of distribution network operators (DNOs) because of the existence of distributed generation (DG) units. The sum of active loss reduction and network investment deferral incentives has been considered as the objective function to be maximised in this study. The optimal location and size of DG units in the network are found considering various techno-economical issues. The application of the proposed methodology in the UK under current Ofgem financial incentives for DNOs is investigated. The ability of the proposed approach in finding the optimal solution is validated by comparing the obtained results with other methods of the literature. [ABSTRACT FROM AUTHOR]

Introduction/background Mapping provides a statistical algorithm that allows the estimation of utilities and consequently calculation of QALYs in clinical studies where preference-based measures are not implemented. Sources of data Reviews of the mapping literature were utilized. Areas of agreement Mapping requires similar populations between the estimation and study data sets, with a high degree of overlap between the target and base measures being desirable. The National Institute for Health and Clinical Excellence recognizes mapping as a method to provide utility information. Areas of controversy Issues surrounding mapping include the descriptive system of the measure, the appropriate econometric method and model specification. Growing points There is a need for further research into the issue of over-prediction for severe health states and uncertainty around the estimated utility scores. Areas timely for developing research Mapping continues to be an important area of research for economic evaluation, in particular validation of mapping functions. [ABSTRACT FROM AUTHOR]

Background Evidence suggests that in decision contexts characterized by uncertainty and time constraints (e.g. health-care decisions), fast and frugal decision-making strategies (heuristics) may perform better than complex rules of reasoning. Objective To examine whether it is possible to design deliberation components in decision support interventions using simple models (fast and frugal heuristics). Design The 'Take The Best' heuristic (i.e. selection of a 'most important reason') and 'The Tallying' integration algorithm (i.e. unitary weighing of pros and cons) were used to develop two deliberation components embedded in a Web-based decision support intervention for women facing amniocentesis testing. Ten researchers (recruited from 15), nine health-care providers (recruited from 28) and ten pregnant women (recruited from 14) who had recently been offered amniocentesis testing appraised evolving versions of 'your most important reason' (Take The Best) and 'weighing it up' (Tallying). Results Most researchers found the tools useful in facilitating decision making although emphasized the need for simple instructions and clear layouts. Health-care providers however expressed concerns regarding the usability and clarity of the tools. By contrast, 7 out of 10 pregnant women found the tools useful in weighing up the pros and cons of each option, helpful in structuring and clarifying their thoughts and visualizing their decision efforts. Several pregnant women felt that 'weighing it up' and 'your most important reason' were not appropriate when facing such a difficult and emotional decision. Conclusion Theoretical approaches based on fast and frugal heuristics can be used to develop deliberation tools that provide helpful support to patients facing real-world decisions about amniocentesis. [ABSTRACT FROM AUTHOR]

There is a discernable mood in macro-level public evaluations of party issue competence. This paper argues that voters use heuristics to transfer issue competence ratings of parties between issues, therefore issue competence ratings move in common. Events, economic shocks and the costs of governing reinforce these shared dynamics. These expectations are analysed using issue competence data in Britain 1950–2008, and using Stimson's dyad ratios algorithm to estimate ‘macro-competence’. Effects on macro-competence are found for events and economic shocks, time in government, leader ratings, economic evaluations and partisanship, but macro-competence also accounts for unique variance in a model of party choice. The article presents an aggregate-level time-series measure to capture the long-term dynamics of ‘valence’. [ABSTRACT FROM PUBLISHER]

the evidence base for the management of severe or life-threathening exacerbations of asthma is not as strong as that for mild or moderate exacerbations. Despite this information deficit, intravenous (IV) salbutamol has become an accepted treatment option for children not responding to inhaled bronchodilator and corticosteroid therapy. Studies have shown that it is used in many centres in the UK replacing IV aminophylline, however, there is wide variation in dosing regimens and inconsistencies in practice. The authors audited their own prescribing practice and developed an algorithm-based approach to the use of IV salbutamol that includes patient selection and all aspects of prescribing, preparation, administration, monitoring and the requirements of the environment where care is delivered. It includes details of the IV salbutamol bolus and the infusion process, incorporating all available evidence. The algorithm provides guidance on IV salbutamol usage in children up to and including 18 years. The authors hope it will promote standardised practice, limit the opportunity for prescribing errors and highlight the need for a national paediatric study comparing IV salbutamol and IV aminophylline. It may also stimulate discussion on the IV salbutamol dosage used in adult practice. [ABSTRACT FROM AUTHOR]

Background: UK medical schools typically have over 300 students per year, making it impossible for students to know all the others well. Aims: This longitudinal cohort study measured the formation of medical student social networks and their relationship to grades. Method: In November 2009, 215/317 (68%) Year 2 UCL medical students reported their friendships with others in their year, by questionnaire. Multiple regression assessed the relationship between friendships, exam results and background variables (obtained from student records), with permutation testing to assess statistical significance. Results: Students of the same sex, the same ethnic group, and in the same tutor and small groups (to which they were randomly assigned at the start of medical school) were socially closer. Taking into account absolute difference in Year 1 grades, Year 2 pairs who were socially closer in November 2009 had more similar May 2010 grades. Individual student variables did not predict similarity in 2010 grades after taking friendships into account. Conclusions: The results suggest that medical students chose friends of the same sex and ethnic group as themselves; but random allocation of students to tutor groups also influenced friendships. Most importantly, friendships related to subsequent exam performance, suggesting friendship may influence learning. [ABSTRACT FROM AUTHOR]

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ABSTRACT: The purpose of this paper is to introduce the conceptualisation and evolution of a trialed Doppler traffic light system for healed venous leg ulceration. This tool aims to facilitate clinical decision-making and provides a systematic approach to the ongoing assessment of arterial disease in patients with healed venous leg ulcers when used in conjunction with other purposely-designed assessment documentation to ensure the novice registered and unregistered nurse contributes safely and effectively to the care of patients. The validation and trial of this clinical decision tool is discussed in terms of the use of a recognised methodology determining its fitness for purpose and robustness. [ABSTRACT FROM AUTHOR]

Background: Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration-response relationship-and, in particular, if there is a threshold-is critical for estimating public health impacts. Objective: We investigated the concentration-response relationship between daily ozone and mortality in five urban and five rural areas in the United Kingdom from 1993 to 2006. Methods: We used Poisson regression, controlling for seasonality, temperature, and influenza, to investigate associations between daily maximum 8-hr ozone and daily all-cause mortality, assuming linear, linear-threshold, and spline models for all-year and season-specific periods. We examined sensitivity to adjustment for particles (urban areas only) and alternative temperature metrics. Results: In all-year analyses, we found clear evidence for a threshold in the concentration-response relationship between ozone and all-cause mortality in London at 65 µg/m3 [95% confidence interval (CI): 58, 83] but little evidence of a threshold in other urban or rural areas. Combined linear effect estimates for all-cause mortality were comparable for urban and rural areas: 0.48% (95% CI: 0.35, 0.60) and 0.58% (95% CI: 0.36, 0.81) per 10-µg/m3 increase in ozone concentrations, respectively. Seasonal analyses suggested thresholds in both urban and rural areas for effects of ozone during summer months. Conclusions: Our results suggest that health impacts should be estimated across the whole ambient range of ozone using both threshold and nonthreshold models, and models stratified by season. Evidence of a threshold effect in London but not in other study areas requires further investigation. The public health impacts of exposure to ozone in rural areas should not be overlooked. [ABSTRACT FROM AUTHOR]

Purpose: To test if two of the adverse event triggers proposed by the Institute of Healthcare Improvement can detect adverse drug events (ADEs) in a UK secondary care setting, using an electronic prescribing and health record system. Methods: In order to identify triggers for over-anticoagulation and potential opioid overdose and we undertook a retrospective review of electronic medical and prescription records from 54,244 hospital admissions over a 1-year period, alongside a review of medical incident reports. Once prescription data were linked to triggers and duplicates were removed, case note review eliminated the false positive ADEs. Additionally, we tested the use of an electronic algorithm for the International Normalized Ratio (INR) ≥6 trigger. Results: The INR ≥6 electronic trigger identified 46 potential ADEs and the naloxone electronic trigger identified 82 ADEs. Based on the available case note review, the INR ≥6 trigger had a positive predictive value (PPV) of 38 % (14/37) and the naloxone trigger had a PPV of 91 % (61/67). The electronic algorithm for the INR ≥6 trigger identified 12 ADEs, thus reducing the need of case note review. This was in comparison with one and two critical incidents reported in the trust medical incident reports system, which respectively related to over-coagulation with warfarin and over-sedation with opioid medication. Conclusions: We have integrated automated and manual methods of detecting ADEs using previously defined triggers. Incorporating electronic triggers in already established electronic health records with prescription and laboratory test data can improve the detection of ADEs, and potentially lead to methods to avert them. [ABSTRACT FROM AUTHOR]

The article discusses Fiber-optic intra-aortic balloon therapy and its role within cardiac surgery, where it states that Fiber-optic manometers provide accurate and fast, high quality measurements. It also mentions effect of fiber-optic IABP therapy on clinical management. It is concluded that Fiber-optic IAB technology and improved algorithms provide better beat per beat mechanical support.

BackgroundPredictD is a risk algorithm that was developed to predict risk of onset of major depression over 12 months in general practice attendees in Europe and validated in a similar population in Chile. It was the first risk algorithm to be developed in the field of mental disorders. Our objective was to extend predictD as an algorithm to detect people at risk of major depression over 24 months.MethodParticipants were 4190 adult attendees to general practices in the UK, Spain, Slovenia and Portugal, who were not depressed at baseline and were followed up for 24 months. The original predictD risk algorithm for onset of DSM-IV major depression had already been developed in data arising from the first 12 months of follow-up. In this analysis we fitted predictD to the longer period of follow-up, first by examining only the second year (12–24 months) and then the whole period of follow-up (0–24 months).ResultsThe instrument performed well for prediction of major depression from 12 to 24 months [c-index 0.728, 95% confidence interval (CI) 0.675–0.781], or over the whole 24 months (c-index 0.783, 95% CI 0.757–0.809).ConclusionsThe predictD risk algorithm for major depression is accurate over 24 months, extending it current use of prediction over 12 months. This strengthens its use in prevention efforts in general medical settings. [ABSTRACT FROM AUTHOR]

Background Introduction of proposed criteria for DSM-5 Autism Spectrum Disorder (ASD) has raised concerns that some individuals currently meeting diagnostic criteria for Pervasive Developmental Disorder (PDD; DSM-IV-TR/ICD-10) will not qualify for a diagnosis under the proposed changes. To date, reports of sensitivity and specificity of the new criteria have been inconsistent across studies. No study has yet considered how changes at the 'sub domain' level might affect overall sensitivity and specificity, and few have included individuals of different ages and ability levels. Methods A set of DSM-5 ASD algorithms were developed using items from the Diagnostic Interview for Social and Communication Disorders (DISCO). The number of items required for each DSM-5 subdomain was defined either according to criteria specified by DSM-5 (Initial Algorithm), a statistical approach (Youden J Algorithm), or to minimise the number of false positives while maximising sensitivity (Modified Algorithm). The algorithms were designed, tested and compared in two independent samples (Sample 1, N = 82; Sample 2, N = 115), while sensitivity was assessed across age and ability levels in an additional dataset of individuals with an ICD-10 PDD diagnosis (Sample 3, N = 190). Results Sensitivity was highest in the Initial Algorithm, which had the poorest specificity. Although Youden J had excellent specificity, sensitivity was significantly lower than in the Modified Algorithm, which had both good sensitivity and specificity. Relaxing the domain A rules improved sensitivity of the Youden J Algorithm, but it remained less sensitive than the Modified Algorithm. Moreover, this was the only algorithm with variable sensitivity across age. All versions of the algorithm performed well across ability level. Conclusions This study demonstrates that good levels of both sensitivity and specificity can be achieved for a diagnostic algorithm adhering to the DSM-5 criteria that is suitable across age and ability level. [ABSTRACT FROM AUTHOR]

Background and purpose An internet-based discrete choice experiment (DCE) was conducted to elicit preferences for a wide range of Dupuytren's contracture (DC)-related health states. An algorithm was subsequently developed to convert these preferences into health state utilities that can be used to assess DC's impact on quality of life and the value of its treatments. Methods Health state preferences for varying levels of DC hand severity were elicited via an internet survey from a sample of the UK adult population. Severity levels were defined using a combination of contractures (0, 45, or 90 degrees) in 8 proximal interphalangeal and metacarpophalangeal joints of the index, middle, ring, and little fingers. Right-handed, left-handed, and ambidextrous respondents indicated which hand was preferable in each of the 10 randomly-selected hand-pairings comparing different DC severity levels. For consistency across comparisons, anatomically precise digital hand drawings were used. To anchor preferences onto the traditional 0-1 utility scale used in health economic evaluations, unaffected hands were assigned a utility of 1.0 whereas the utility for a maximally affected hand (i.e., all 8 joints set at 90 degrees of contracture) was derived by asking respondents to indicate what combination of attributes and levels of the EQ-5D-5L profile most accurately reflects the impact of living with such hand. Conditional logistic models were used to estimate indirect utilities, then rescaled to the anchor points on the EQ-5D-5L. Results Estimated utilities based on the responses of 1,745 qualified respondents were 0.49, 0.57, and 0.63 for completely affected dominant hands, non-dominant hands, or ambidextrous hands, respectively. Utility for a dominant hand with 90-degree contracture in t h e metacarpophalangeal joints of the ring and little fingers was estimated to be 0.89. Separately, reducing the contracture of metacarpophalangeal joint for a little finger from 50 to 12 degrees would improve utility by 0.02. Interpretation DC is associated with substantial utility decre- ments. The algorithms presented herein provide a robust and flexible framework to assess utility for varying degrees of DC severity. [ABSTRACT FROM AUTHOR]

This article outlines a strategic process for the evaluation of wound management products and the development of an algorithm as an implementation model for wound management. Wound management is an increasingly complex process given the variety of interactive dressings and other devices available. This article discusses the procurement process, access to wound management dressings and the use of wound management formularies within the UK. We conclude that the current commissioners of tissue viability within healthcare organisations need to adopt a proactive approach to ensure appropriate formulary evaluation and product selection, in order to achieve the most beneficial clinical and financial outcomes. [ABSTRACT FROM AUTHOR]

This project was developed to set up a nurse-led service based on the needs of patients diagnosed with 'red legs'. These patients are often wrongly admitted into hospital for treatment of cellulitis. Representatives from the specialties involved in caring for those individuals with red legs were invited to participate with patients to create a stakeholder group whose purpose was to develop integrated care pathways focused on referral criteria, diagnostics and treatment to inform a new nurse-led service. There was a commitment to utilising a number of facilitation techniques and practicedevelopment methods in the progression of the project with the support of the Foundation of Nursing Studies. Much of the prescribed care can be carried out by the patients at home and only 25% patients have required a follow-up appointment within the new service. The service has now been fully commissioned and a secondment opportunity has been developed to lead the new service. Significant savings have been demonstrated and regular revision of the integrated care pathways with all groups, including the patients, will take place. [ABSTRACT FROM AUTHOR]

Objective An international panel of pain specialists (anesthesiology, neurology, neurosurgery, and psychology) and research methodologists developed a screening tool to identify patients who may be suitable for spinal cord stimulation ( SCS)-the Refractory Chronic Pain Screening Tool ( RCPST) prototype. We describe a feasibility study to explore practicality and validity of this prototype. Design Consecutive outpatients were screened in two centers ( United Kingdom and United States). Sixty chronic pain adults without satisfactory pain relief despite treatment were assessed using RCPST (by pain specialist without expertise in neurostimulation) and then evaluated by two pain specialists experienced in SCS implantation and management to determine whether the patient should be referred for SCS. To maintain blinding, the participating physicians did not inform each other or the patient of assessment outcome. Sensitivity and specificity of the RCPST prototype were calculated using implanters' judgment as 'gold standard.' Results The average age of patients was 47.7 years; 53% were female. Fifty-seven patients completed the study (one withdrew consent, two lost to follow-up). The pain specialists agreed the prototype was easy to use and took <10 minutes to complete. Implanter agreement was moderate ( Kappa: 0.63, 95% confidence interval: 0.35-0.91). The prototype had low sensitivity (40%, 19-61%) and moderate specificity (78%, 65-92%). Using the same questionnaire with a modified decision algorithm, new prototypes were generated with range of high sensitivity (80-100%) and specificity (89-97%) values. Conclusions The RCPST aims to identify patients that should be referred for consideration for neurostimulation. The final implant decision requires appropriate neurological diagnostic workup, psychological assessment, and trial stimulation. RCPST was considered practical for routine clinical practice and contained appropriate questions. Sensitivity needs to be improved. A future study should select and validate the ideal RCPST prototype. [ABSTRACT FROM AUTHOR]

Since the first launch of the new engineering contract (NEC) in 1993, early warning of problems has been widely recognized as an important approach of proactive management during a construction or engineering project. Is early warning really effective for the improvement of problem solving and project performance? This is a research question that still lacks a good answer. For this reason, an empirical investigation was made in the United Kingdom (U.K.) to answer the question. This study adopts a combination of literature review, expert interview, and questionnaire survey. Nearly 100 questionnaire responses were collected from the U.K. construction industry, based on which the use of early warning under different forms of contract is compared in this paper. Problem solving and project performance are further compared between the projects using early warning and the projects not using early warning. The comparison provides clear evidence for the significant effect of early warning on problem solving and project performance in terms of time, cost, and quality. Subsequently, an input-process-output model is developed in this paper to explore the relationship among early warning, problem solving, and project performance. All these help construction researchers and practitioners to better understand the role of early warning in ensuring project success. [ABSTRACT FROM AUTHOR]

The article highlights a comment on the report on parameter estimation of the nonlinear Muskingum Flood-Routing model using a hybrid harmony search algorithm. Topics discussed include a review of the first case study presented in the report that can be considered as a benchmark problem in estimation of the nonlinear Muskingum model parameters and another on the second case study focused on a real flood event in Great Britain in 1960.