1,721,024 research outputs found
Flu incidence variations in Azerbaijan for the years 1976-2000: non-linear modelling and forecasting
No full textCyclic variations in the dynamics of flu incidence in Azerbaijan 1976-2000
No full textMulticomponent cyclicity in influenza (flu) incidence had been observed in various countries (e.g. periods T = 1, 2–3, 5–6, 8·0, 10·6–11·3, 13, 18–19 years) and its close similarity with cycles in natural environmental phenomena as meteorological factors and heliogeophysical activity (HGA) suggested. This report aimed at verifying previous results on cyclic patterns of flu incidence by exploring whether flu annual cyclicity (seasonality) and trans-year (13 to <24 months) and/or multiannual (long-term, ?24 months) cycles might be present. For this purpose, a relatively long monthly flu incidence dataset consisting of absolute numbers of new cases from the Grand Baku area, Azerbaijan, for the years 1976–2000 (300 months) was analysed. The exploration of underlying chronomes or, time structures, was done by linear and nonlinear parametric regression models, autocorrelation, spectral analysis and periodogram regression analysis. We analysed temporal dynamics and described multicomponent cyclicity, determining its statistical significance. The analysis, considering the flu data specifically stratified in three distinct intervals (1976–1990, 1991–1995, 1996–2000), and also combinations thereof, indicated that the main cyclic pattern was a seasonal one, with a period of T = 12 months. Further, a number of multiannual cycles with periods T in the ranges of 26–36, 62–85 or 113–162 months were observed, i.e. average periods of 2·5, 6·1 and 11·5 years, respectively. Indeed, most of these cycles correspond to similar cyclic parameters of HGA and further analyses are warranted to investigate such relationships. In conclusion, our study revealed the presence of multicomponent cyclic dynamics in influenza incidence by using relatively long time-series of monthly data. The specific cyclic patterns of flu incidence in Azerbaijan allows further, more specific modelling and correlations with environmental factors of similar cyclicity, e.g. HGA, to be explored. These results might contribute more widely to a better understanding of influenza dynamics and its aetiology as well as to the derivation of more precise forecasted estimates for planning and prevention purposes
Diastolic blood pressure cut-off predicts major cerebrovascular events after minor ischaemic stroke: a post-hoc modelling study
No full textOnly few follow-up studies have studied in detail the role of most important risk factors, but no reports were found on critical values (cut-offs) for such factors in prospectively predicting cerebrovascular events (CVE) in patients with minor ischaemic stroke (MIS). Estimates of predictive importance of such cut-offs may better inform and contribute to optimize treatment. This was a post-hoc modelling study with unique data from Bulgaria on 54 consecutive patients with MIS, aged ? 40, followed for 12 months for nonfatal or fatal CV events. A set of routine clinical demographic and known risk factors (SBP, DBP, HDL cholesterol, etc.) were explored using univariate statistics and multivariate regression models to identify the most important independent predictors of secondary CVE. An artificial neural network (ANN) model, irrespective of usual statistical constraints, also confirmed the specific role and importance of identified predictors. A receiver operating characteristics (ROC) curve and stratified survival analyses were used to define the best cut-off of most important predictors and validate the final model. During follow-up period of 11.1±2.4 months, 8 secondary CV events (14.8%) were observed only in males with MIS at the 5.8±2.7 months mark. No difference in age of patients with CV event (61.1±12.6 years) vs. those without (62.1±9.6 years) was found (p>0.05). The one-year risk for CVE was.15% (95%CI 7.1, 27.7%). The two most important risk factors in patients with versus without CV events were acute MIS onset (62.5 vs. 13.0%) and mean DBP at day 30 post-MIS (101.3±9.9 vs. 92.3±10.8 mmHg), with a relative importance by ANN of 20.92 versus 15.9 points, respectively. At multivariate logistic analysis only MIS onset and DBP were independently associated with the risk for secondary CVE (79.6% model accuracy, p model=0.0015). An increase of DBP with 1 mmHg was associated with 8% higher risk of CVE [adjusted OR=1.08 (95%Cl 1.004, 1.158)]. With this method, a novel cut-off predictive DBP value of 95 mmHg (ROCAUC=0.79, 95%Cl 0.60, 0.99, p=0.009) for CV events in patients with MIS has been found. In conclusions the new DBP cut-off (sensitivity >87%, specificity >69%) clearly discriminated between absence and presence of secondary CVE as also confirmed by stratified survival analysis (7 vs. 1 events, plog-rank =0.0103). This cut-off may be applied to better precisely evaluate and define, as earlier as possible, MIS patients at increased risk of secondary CV event
Cyclicity of suicides may be modulated by internal or external 11 year cycles: an example of suicide rates in Finland
No full textA concept for a long-term scalable bioengineering model of primary care
No full textWe present a concept for development of a unified bioengineering framework that consolidates efforts in extending the geographical boundaries and outreach of primary care in Ireland and ensure its long-term scalability. This framework encompasses infrastructures, devices, systems, techniques, materials, engineering practices and socio-technical set-ups for improved access, safety and quality of care at national and global levels. In particular, we address the development of special purpose solutions, technologies and devices for healthcare from a bioengineering perspective, within the wider healthcare and biotechnology agendas in Ireland
Cerebral malaria admissions in Papua New Guinea may show inter-annual cyclicity: An example of about a 1.5-year cycle for malaria incidence in Burundi
Full text linkBest available descriptions of malaria incidence and mortality dynamics are important to better plan and evaluate the implementation of programs to monitor (e.g., remote sensing) and control the disease, especially in endemic zones. This was stressed recently by Cibulskis et al (2007) in the view of completeness of monthly reporting for cerebral malaria admissions in Papua New Guinea (latitude 6 degree S, 1987-1996). Notably, regardless of the rate of its completeness, the temporal dynamics of admissions was preserved over the years, however, neither raw data nor results on further analyses about eventual inter-annual cyclic components (periods T>1 year) were provided despite obvious graphical patterns for such a specific time structure (chronome). Interestingly, in a recent analysis by Gomez-Elipe et al (2007) on monthly malaria notifications in Burundi, at almost the same latitude (province of Karuzi, >3 degree S, 1997-2001), the data have shown neither trend not periodic oscillations beyond a 6-month (0.5-year) period. Since the graphical representation of both data sets have indicated an eventual existence of inter-annual variations, and because both are located at the same latitude zone, we have further analyzed the data from Burundi for such periodic oscillations. By using a periodogram regression analysis, we discovered a multicomponent cyclic chronome with periods above 12 months (T=17.5-18.0, 27.5 and 65.0-65.5 months, all at p<0.05). Notably, the most strong cyclic pattern at p<0.002 in the periodogram of the detrended malaria rates in Burundi remained only that with a peak at about 1.5 years (period T=17.5-18.0 months, R=0.51, z=5.3). It is possible that likely inter-annual cyclic patterns might exist also in the time structure for cerebral malaria admissions in Papua New Guinea and, if confirmed, these may be found very useful in epidemic forecasting and programs implementation. We explored these cyclic variations and also discussed possible associations with environmental factors exhibiting alike cyclicity
New simplified approach to the pooled analysis of calibration of clinical prediction rules for systematic reviews of validation studies
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Digital content preservation across domain verticals
No full textThe authors present a novel approach to develop scalable systems and services for preserving digital content generated from various application domains. The aim is to deliver an integrative scalable approach for digital content preservation across domain verticals. This would involve consolidating approaches for modeling document workflow, preserving the integrity of heterogeneous data, and developing robust and scalable tools for digital preservation ensuring interoperability across domains verticals. The authors consider various application domains including: healthcare, public, business and finance, media and performing art, and education. The authors focus on specific case studies of digital content preservation across the considered domain verticals. The authors describe an integrative framework for digital content preservation across domain verticals. This framework is developed at four levels and attempts to abstract and integrate the digital content workflow across domain verticals. The authors suggest a test bed to validate our integrative approach for digital content preservation. This integrates the digital content preservation activity along the value chain of domain verticals.</p
Primary health care models and suitability for provision of e-services: an overview
No full textWe present an overview of the most frequently distributed types of primary health care (PHC) models of delivery across different countries and cultural environments. We summarise and describe most important definitions, principles of classification, attributes, necessary conditions (e.g., patient-management systems, electronic health records, ICT platforms) and organisation and key performance indicators (KPI) for functioning of the primary health care systems. We review and explore the suitability of different PHC models for provision of electronic (e-)services.</p
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