Associations between Extending Access to Primary Care and Emergency Department Visits: A Difference-In-Differences Analysis

Background: Health services across the world increasingly face pressures on the use of expensive hospital services. Better organisation and delivery of primary care has the potential to manage demand and reduce costs for hospital services, but routine primary care services are not open during evenings and weekends. Extended access (evening and weekend opening) is hypothesized to reduce pressure on hospital services from emergency department visits. However, the existing evidence-base is weak, largely focused on emergency out-of-hours services, and analysed using a before-and after-methodology without effective comparators. Methods and Findings: Throughout 2014, 56 primary care practices (346,024 patients) in Greater Manchester, England, offered 7-day extended access, compared with 469 primary care practices (2,596,330 patients) providing routine access. Extended access included evening and weekend opening and served both urgent and routine appointments. To assess the effects of extended primary care access on hospital services, we apply a difference-in-differences analysis using hospital administrative data from 2011 to 2014. Propensity score matching techniques were used to match practices without extended access to practices with extended access. Differences in the change in “minor” patient-initiated emergency department visits per 1,000 population were compared between practices with and without extended access. Populations registered to primary care practices with extended access demonstrated a 26.4% relative reduction (compared to practices without extended access) in patient-initiated emergency department visits for “minor” problems (95% CI -38.6% to -14.2%, absolute difference: -10,933 per year, 95% CI -15,995 to -5,866), and a 26.6% (95% CI -39.2% to -14.1%) relative reduction in costs of patient-initiated visits to emergency departments for minor problems (absolute difference: -£767,976, -£1,130,767 to -£405,184). There was an insignificant relative reduction of 3.1% in total emergency department visits (95% CI -6.4% to 0.2%). Our results were robust to several sensitivity checks. A lack of detailed cost reporting of the running costs of extended access and an inability to capture health outcomes and other health service impacts constrain the study from assessing the full cost-effectiveness of extended access to primary care. Conclusions: The study found that extending access was associated with a reduction in emergency department visits in the first 12 months. The results of the research have already informed the decision by National Health Service England to extend primary care access across Greater Manchester from 2016. However, further evidence is needed to understand whether extending primary care access is cost-effective and sustainable

A hybrid neural network classifier combining ordered fuzzy ARTMAP and the dynamic decay adjustment algorithm

This paper presents a novel conflict-resolving neural network classifier that combines the ordering algorithm, fuzzy ARTMAP (FAM), and the dynamic decay adjustment (DDA) algorithm, into a unified framework. The hybrid classifier, known as Ordered FAMDDA, applies the DDA algorithm to overcome the limitations of FAM and ordered FAM in achieving a good generalization/performance. Prior to network learning, the ordering algorithm is first used to identify a fixed order of training patterns. The main aim is to reduce and/or avoid the formation of overlapping prototypes of different classes in FAM during learning. However, the effectiveness of the ordering algorithm in resolving overlapping prototypes of different classes is compromised when dealing with complex datasets. Ordered FAMDDA not only is able to determine a fixed order of training patterns for yielding good generalization, but also is able to reduce/resolve overlapping regions of different classes in the feature space for minimizing misclassification during the network learning phase. To illustrate the effectiveness of Ordered FAMDDA, a total of ten benchmark datasets are experimented. The results are analyzed and compared with those from FAM and Ordered FAM. The outcomes demonstrate that Ordered FAMDDA, in general, outperforms FAM and Ordered FAM in tackling pattern classification problems.<br /

An online pruning strategy for supervised ARTMAP-based neural networks

Identifying an appropriate architecture of an artificial neural network (ANN) for a given task is important because learning and generalisation of an ANN is affected by its structure. In this paper, an online pruning strategy is proposed to participate in the learning process of two constructive networks, i.e. fuzzy ARTMAP (FAM) and fuzzy ARTMAP with dynamic decay adjustment (FAMDDA), and the resulting hybrid networks are called FAM/FAMDDA with temporary nodes (i.e. FAM-T and FAMDDA-T, respectively). FAM-T and FAMDDA-T possess a capability of reducing the network complexity online by removing unrepresentative neurons. The performances of FAM-T and FAMDDA-T are evaluated and compared with those of FAM and FAMDDA using a total of 13 benchmark data sets. To demonstrate the applicability of FAM-T and FAMDDA-T, a real fault detection and diagnosis task in a power plant is tested. The results from both benchmark studies and real-world application show that FAMDDA-T and FAM-T are able to yield satisfactory classification performances, with the advantage of having parsimonious network structures.<br /

Phylogeny, historical biogeography and characters evolution of the drought resistant fern Pyrrosia Mirbel (Polypodiaceae) inferred from plastid and nuclear markers

Abstract Pyrrosia s.l. comprises ca. 60 species with a disjunct Africa/Asia and Australia distribution. The infrageneric classification of Pyrrosia s.l. is controversial based on the phylogenetic analyses of chloroplast markers and morphology. Based on the expanded taxon sampling of Pyrrosia s.l. (51 species), we investigated its phylogeny, biogeography, character evolution and environmental adaptation by employing five chloroplastid markers (rbcL, matK, psbA-trnH, and rps4 + rps4-trnS) and one single (low)-copy nuclear gene, LEAFY. Pyrrosia s.l. was divided into six major clades and eight subclades. Reticulate evolution was revealed both among clades and among species in Pyrrosia s.l. Ancestral character state optimization revealed high levels of homoplastic evolution of the diagnostic characters in Pyrrosia s.l., while the crassulacean acid metabolism pathway seems to have an independent origin. Molecular dating and biogeographic diversification analyses suggested that Pyrrosia s.l. originated no later than the Oligocene and the main clades diversified during the Oligocene and Miocene, with southern Asia, the Indo-China Peninsula and southwestern and southern China as the most likely ancestral areas. Transoceanic long-distance dispersal, rather than vicariance, contributed to the intercontinental disjunction. Diversification scenarios of Pyrrosia s.l. under geological movements and climate fluctuation are also discussed

Contrasting effects of habitat complexity and connectivity on biodiversity in seagrass meadows

Variability in habitat positioning within seascapes (over kilometres) influences fauna assemblage composition, but the characteristics of a habitat patch (10–100s of metres) influence how species use that patch and how variable assemblages are within habitats. Understanding the relative influence of these two contrasting scales is crucial to improving the management of marine habitats. We used baited remote underwater video systems (BRUVS) to quantify seagrass fish assemblages, and took seagrass cores to quantify seagrass metrics, at ten sites across three seasons in Moreton Bay, Australia to determine if fish are influenced more by seascape context or metrics of seagrass habitat complexity. We found that fish species richness and assemblage composition are most influenced by large-scale variability in seascape (e.g. proximity to ocean and mangroves). However, variability in habitat complexity (e.g. seagrass blade length and density) and proximity to mangrove forests had the greatest effect on assemblage beta diversity. Connectivity with other habitats plays a vital role in structuring the fish community, as it is crucial for daily feeding excursions (mangrove forests) and spawning/reproduction (proximity to ocean). Continuous, non-patchy seagrass beds are however vital to how individuals use a seagrass meadow, with beta diversity being higher in seagrass meadows that were less patchy. Identifying how habitat attributes and context influence fish assemblages is vital for optimizing conservation initiatives. Therefore, we suggest that monitoring populations with biodiversity metrics such as beta diversity can be effective in determining areas that are critical for conservation