Several approaches have been proposed for risk-stratification and primary prevention of coronary heart disease (CHD), but their comparative and cost-effectiveness is unknown.We constructed a state-transition microsimulation model to compare multiple approaches to the primary prevention of CHD in a simulated cohort of men aged 45–75 and women 55–75. Risk-stratification strategies included the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines on the treatment of blood cholesterol, the Adult Treatment Panel (ATP) III guidelines, and approaches based on coronary artery calcium (CAC) scoring and C-reactive protein (CRP). Additionally we assessed a treat-all strategy in which all individuals were prescribed either moderate-dose or high-dose statins and all males received low-dose aspirin. Outcome measures included CHD events, costs, medication-related side effects, radiation-attributable cancers, and quality-adjusted-life-years (QALYs) over a 30-year timeframe.Treat-all with high-dose statins dominated all other strategies for both men and women, gaining 15.7 million QALYs, preventing 7.3 million myocardial infarctions, and saving over $238 billion, compared to the status quo, far outweighing its associated adverse events including bleeding, hepatitis, myopathy, and new-onset diabetes. ACC/AHA guidelines were more cost-effective than ATP III guidelines for both men and women despite placing 8.7 million more people on statins. For women at low CHD risk, treat-all with high-dose statins was more likely to cause a statin-related adverse event than to prevent a CHD event.Despite leading to a greater proportion of the population placed on statin therapy, the ACC/AHA guidelines are more cost-effective than ATP III. Even so, at generic prices, treating all men and women with statins and all men with low-dose aspirin appears to be more cost-effective than all risk-stratification approaches for the primary prevention of CHD. Especially for low-CHD risk women, decisions on the appropriate primary prevention strategy should be based on shared decision making between patients and healthcare providers. Cardiovascular disease, and in particular coronary heart disease (CHD), is now the leading cause of death and disability-associated life years both globally and in the United States ,2. WhileWhile Framingham Risk Scores (FRS) have been demonstrated to correlate well with future risk of CHD , recent We constructed a state-transition (Markov) microsimulation model in TreeAge Pro Suite 2009 . The model evaluated the target population, suggested in SHAPE, of US men aged 45–75 and women aged 55–75 who are asymptomatic defined as having no prior CHD event, which would include myocardial infarction or coronary revascularization as well not having a CHD equivalent such as diabetes. It was treated as a closed-cohort population and individuals were followed in the model until either their death or for 30 years. In 2010, this population would represent 46.9 million men and 27.3 million women . Baselinmoderate-dose statins and all men with aspirin 81mg daily; (8) and treating everyone with high-dose statins and all men with aspirin 81mg daily. Except for the JUPITER strategy, we assumed that all patients assigned to high-dose statins received 80mg of atorvastatin. All risk stratification  strategies, excluding status quo, included low-dose aspirin for men with FRS>10%. For the CAC- and CRP-based strategies any person who did not meet inclusion criteria for each strategy was treated based on the ATP III guidelines.Eight strategies were compared : (1) theFor the 2013 ACC/AHA guidelines strategy, in order to determine the PCE distribution of 10-year ASCVD risk in our patient population we utilized the known correlation of FRS to Pooled Cohort risk as demonstrated in the appendix to the 2013 guidelines  of all studies of high-dose atorvastatin that reported adverse event outcomes –53. FromIn order to validate our model outcomes with current data regarding the incidence of CHD, we correlated the predicted incidence of new CHD from our model with the most up-to-date statistics on CHD incidence in the US population based on calculating the actual rates of CHD from the US Heart Disease and Stroke statistics for men aged 45–75 and women aged 55–75 years old .Over a 30-year time frame (2011–2040), future costs and QALYs were discounted by 3% annually . SeparatWhile the basecase model was based on a probabilistic sensitivity analysis, we performed several additional sensitivity analyses to assess the impact of key assumptions: the effects of aspirin use, the effect of varying adherence to medical therapy based on one knowing their CAC score as opposed to adherence rates demonstrated in the ‘real-world’ primary prevention patient population, varying radiation dosages from CAC tests, and the magnitude of disutility from statins. Regarding aspirin use for men, we assessed the following alternative assumptions: 1) aspirin was only prescribed for men with an FRS > 10% even in the treat-all arm, 2) in CAC-based interventions, aspirin was only prescribed when CAC > 0, and 3) aspirin was not prescribed in any interventions. Additionally, as there may be additional consequences of daily statin therapy not modeled in our basecase model including  decreaseAdditionally, subgroup analyses in which the costs of each strategy, as well as the number of individuals that would need to be included in a given strategy to prevent one CHD event , and the number of individuals who would need to be included in a given strategy to lead to one additional strategy-related adverse event  as compared to both the status quo and to ATP III simulations were performed. Subgroups evaluated included outcomes assessed for males and females separately as well as by age, with outcomes determined for men age 45–54, 55–64, and 65–74 years old and women age 55–64 and 65–74 years old separately. In order to assess outcomes in the low-risk population we performed additional sub-group analysis for men and women with an FRS <5%.Lastly, in order to compare the results and global impact of our modeled strategies to other population wide interventions aimed at the primary prevention of CHD we compared the number of CHD events prevented, QALYs gained, and costs saved of the modeled ACC/AHA guidelines and a treat-all with high-dose statins approach to the following previously studied interventions: 1) Intensive behavior modification aimed at improving diet, increased exercise and physical activity, and weight loss which would lead to a 5% decrease in body mass index (BMI) nationally ,84, 2) aThe basecase results are summarized in Regardless of the willingness-to-pay threshold used, , treat-aOur model results for incidence of CHD for the status quo simulation were markedly similar to the actual real incidence of CHD in our studied population. The most recent US national statistics from the American Heart Association demonstrated 10.3 million new cases of CHD in males age 45 to 75 and 3.9 million in females age 55 to 75, while our model predicted that there would be 12.7 million cases of new CHD in males and 3.3 million cases of new CHD in females in the same age ranges.For men, regardless of the adherence rate for non-CAC based strategies tested, even as low as 19%, treat-all with high-dose statins dominated all other strategies and treat-all with moderate-dose statins dominated all risk-stratification based approaches  varies between cultures and depending on individual patient preferences, underscoring the difficulties inherent in providing uniform CHD prevention recommendations for all patients. In many cases, and in particular for low-risk women, it may be difficult to recommend global statin treatment, as suggested in one recent analysis contending that primary prevention strategies recommending statin therapy for low-risk populations may be misguided . Rather,The recently released ACC/AHA lipid lowering guidelines change the approach of risk-stratification from basing the initiation and escalation of statin therapy on reaching a person’s goal LDL-C level and instead focus on initiating statin therapy based on an individual’s global cardiovascular risk as calculated by the PCE. These guidelines have been met with skepticism by many in the cardiovascular community since the PCE seems to overestimate risk and if implemented worldwide could lead to over 1 billion individuals being placed on statin therapy ,99. AddiGiven that generic atorvastatin is now available at inexpensive wholesale prices, our results beg the consideration of potential ways to lower eligibility thresholds for statin therapy, such as policies that have recently been proposed including allowing for over-the-counter sale of statins , or encoThe additional analysis we performed in which we compared our modeled strategies to other population based approaches aimed at the primary prevention of CHD demonstrated that large scale sustained approaches such as decreasing salt intake globally by 3 grams per day or continued smoking cessation of 1% annually for 30 years would lead to equivalent CHD reduction and QALYs saved as compared to ACC/AHA guideline implantation. While treat-all with high-dose statins would lead to a greater improvement in quality of life than salt reduction it would save less money, and thus salt reduction and smoking cessation may realize a given QALY reduction at a lower cost as compared to a treat-all approach. Placing our modeled strategies in the context of other non-statin based primary-prevention strategies not only allows for a comparison of effective primary prevention strategies, but it also highlights the importance of not placing primary prevention strategies in a vacuum. It is important to encourage multiple approaches to primary prevention, as encouraging our patients to pursue healthy lifestyles, decrease salt intake, and stop smoking, in conjunction with the judicious use of statins in appropriate patients will provide an even bigger impact in the global reduction of CHD than pursuing each of these strategies in isolation.Our study has several limitations. Our analysis assumed that all persons aged 45–75 would be capable of undergoing CAC testing, nobody would be lost to follow up, and that there is no disutility from diagnostic tests other than increased cancer risk from radiation exposure. While statins display potent effects on lowering LDL-C and CHD risk there are many lifestyle modification strategies such as weight loss, smoking cessation, and regular exercise that can markedly decrease a person’s risk of developing CHD that were not included in our model. Our model is limited by the inclusion criteria of each of the individual risk stratification approaches we evaluated, and while it would be ideal to evaluate more than just the effect of lipid lowering on the primary prevention of CHD it is not possible to concurrently assess the effect of blood pressure reduction as only a limited number of risk stratification approaches include blood pressure as a means to estimate risk while all approaches we evaluated included LDL-C level. Additionally, our model did not specifically take into account competing risks from non-CHD diseases and thus may have underestimated health benefits and cost-savings associated with statins and aspirin. While there is likely a significant reduction in the primary prevention of ischemic stroke from statin therapy , 105, anOur analysis may also underestimate costs as we did not assign costs or decreased quality of life related to patient time lost as a result of either diagnostic testing or physician visits. We utilized a PSA approach to account for the joint uncertainties of our model inputs, but were unable to include the parameters of every model input in our PSA since we only included the distribution of input parameters that were well known from the literature. Additionally, while there has been some thought that those with higher CRP levels may derive a greater benefit from statins as compared to those with lower CRP levels, we only modeled a consistent benefit of Rosuvastatin on CHD reduction as this correlation between CRP level and statin efficacy was not noted in the JUPITER trial . While tOur model followed individuals until either their death or for 30 years after entering the model. By using a 30 year time horizon, men entering the model at age 45 years old will only be 75 years old when they are terminated out of the model. After age 75 they will still be at a high risk of accruing additional CHD events and costs. While ideally these events should be captured in our model, it is very difficult to interpret how an individual’s CHD risk today will affect their future CHD risk more than 30 years from now. The ACC/AHA guidelines for risk assessment, which include a discussion of assessing very long-term risk, state that there is insufficient evidence to date to allow us to make predictions of risk more than 30 years from now.  Thus, whIn conclusion, our analysis is the first comprehensive cost-effectiveness simulation to compare multiple prevention and risk-stratification strategies for the primary prevention of CHD including treating the entire at-risk population with statins, utilizing CAC-based approaches including the SHAPE guidelines, applying CRP-based approaches such as in the JUPITER trial, following the ATP III guidelines, and implementing the ACC/AHA lipid guidelines. Under a wide range of scenarios evaluated, treating all men and women with high-dose, generic-priced statins and all men with low-dose aspirin is the most cost-effective approach for the primary prevention of CHD, while the 2013 ACC/AHA guidelines are more cost-effective than the ATP III guidelines despite placing a greater proportion of the population on statin therapy. While treating all individuals with high-dose generic statins remains the most cost-effective approach even for the lower-risk population, the reduction in CHD from statin therapy in the low-risk population, and particularly for women, must be balanced with the risk of statin-related adverse events.S1 FileTable A: Distribution of 10-year risk of incident CHD per the FRS distribution versus the 10-year risk for a ASCVD event in per the Pooled Cohort Equation. Table B: Coronary heart disease and non-coronary heart disease mortality rates. Table C: FRS distribution by age and gender. Table D: baseline LDL-C level by FRS. Table E: Results of adverse event rates from a meta-analysis of high-dose statin therapy. Table F: Results from adherence based sensitivity analyses. Table G: Results from statin disutility based sensitivity analyses. Table H: Results from aspirin based sensitivity analyses. Table I: Results from CAC radiation dose based sensitivity analyses. Table J: Results When Prescribing Moderate-dose Statins in the ACC/AHA Guideline Strategy for those with a Pooled Cohort Risk of 5–7.4%.(DOCX)Click here for additional data file.


Underlying data and tools are available at https://cansar.icr.ac.uk/cansar/publications/druggable_network_neighbourhoods/.The interaction environment of a protein in a cellular network is important in defining the role that the protein plays in the system as a whole, and thus its potential suitability as a drug target. Despite the importance of the network environment, it is neglected during target selection for drug discovery. Here, we present the first systematic, comprehensive computational analysis of topological, community and graphical network parameters of the human interactome and identify discriminatory network patterns that strongly distinguish drug targets from the interactome as a whole. Importantly, we identify striking differences in the network behavior of targets of cancer drugs versus targets from other therapeutic areas and explore how they may relate to successful drug combinations to overcome acquired resistance to cancer drugs. We develop, computationally validate and provide the first public domain predictive algorithm for identifying druggable neighborhoods based on network parameters. We also make available full predictions for 13,345 proteins to aid target selection for drug discovery. All target predictions are available through  cansar.icr.ac.uk).The need for well-validated targets for drug discovery is more pressing than ever, especially in cancer in view of resistance to current therapeutics coupled with late stage drug failures. Target prioritization and selection methodologies have typically not taken the protein interaction environment into account. Here we analyze a large representation of the human interactome comprising almost 90,000 interactions between 13,345 proteins. We assess these interactions using an extensive set of topological, graphical and community parameters, and we identify behaviors that distinguish the protein interaction environments of drug targets from the general interactome. Moreover, we identify clear distinctions between the network environment of cancer-drug targets and targets from other therapeutics areas. We use these distinguishing properties to build a predictive methodology to prioritize potential drug targets based on network parameters alone and we validate our predictive models using current FDA-approved drug targets. Our models provide an objective, interactome-based target prioritization methodology to complement existing structure-based and ligand-based prioritization methods. We provide our interactome-based predictions alongside other druggability predictors within the public canSAR resource ( Identifying novel drug targets and prioritizing proteins for target validation and therapeutic development are essential activities in modern mechanism-driven drug discovery, and are key if we are to benefit from large-scale genomic initiatives . MultiplWhile many genes have been identified as disease-causing  all targets of FDA-approved drugs, which in turn was divided into b) targets of cancer drugs and c) targets of drugs from non-cancer therapeutic areas; and finally d) cancer proteins—the products of cancer associated genes. We then trained suites of predictive models using each of these training sets to predict druggability using only network topological, community and graph features see .−16 compared to 0.018 for the randomized network model; cancer drug targets, p-value = < 2.0−16 compared to 0.125 for the randomized network model and non-cancer-drug targets, p-value = < 2.0−16 compared to 0.331 compared to the randomized network model. Thus, the models have high predictive power using extensive in silico validation and can, therefore, be used to enrich potential drug targets during target prioritization for drug discovery. The full results are provided in https://cansar.icr.ac.uk/) alongside previously described structure-based and ligand-based methodologies [Our predictive models achieve a mean area-under-the-curve (AUC) value of 83%  are drug targets, all of which are targeted by cancer drugs. This indicates that a large number of first neighbors are not generically associated with being a drug target, but rather the average is skewed by a few highly connected cancer-drug targets.ab initio identification of drug targets for cancer or for non-cancer drugs.Network articulation points are nodes that are critical for communication within the network and their removal would disconnect the network into separate graphs or break off peripheral nodes into unconnected singletons. Our analysis shows that 15% of all drug targets, 17% of cancer-drug targets and 14% of non-cancer drug targets are articulation points as compared to 9% of the background set . In order to uncover which network features play the most important role we examined the feature contributions for each of the models generated see . We findOf the 343 drug targets in our interactome, 310 (90%) ranked in the top 25% for druggability according to the overall drug target model. This is a 3.6-fold enrichment of drug targets compared with what might be expected if proteins were ranked at random. In addition to the 343 targets of already FDA approved drugs, a further 3,026 currently undrugged proteins in this top-quartile most druggable set see , highligTo examine the persistence of the signal we investigated the predictive models and target coverage across different datasets. First, we explored the effect of utilizing large-scale Yeast2Hybrid (Y2H) data instead of compiling all high-quality binary interaction data from different sources. Although the Y2H technique is unbiased, we found many interactions were missing from the interactome. This is probably because the full matrix of bait-and-prey proteins has not yet been fully examined. We describe this analysis in detail under the section ‘Defining the interactome’ in Additionally, we defined non-redundant versions of the training sets based on protein sequence similarity, drug chemical similarity and therapeutic class similarity see . Again, To identify potential novel drug targets, we collated the top 20 proteins, that are not targets of approved pharmaceuticals and are predicted to be druggable using each of our three models (removing any duplicates). This resulted in a set of 49 proteins shown in Additionally, among the 49 top proteins are 18 cell surface proteins and several secreted growth factors . It is iTo compare our network druggability assessment with other methods of scoring druggability, we used the protein annotation tool in canSAR ,34,42 toAn annotated, community-correlated map of the human interactome as described in this study is shown in This global view highlights large numbers of potentially missed opportunities and novel target spaces that can be explored, provided that these potential targets are validated for disease causation. Chemical exploration of these barren areas of the interactome, that are predicted to be druggable by both structure- and network-based methodologies, may well yield novel targets for future drug discovery.There is a striking difference in the behavior of the cancer-drug versus non-cancer drug targets in the key network parameters described above, such as community behaviors and graphlet structures. This poses an important question: do these, apparently inherent properties of cancer-drug targets, make it easier for the cell to adapt signaling cascades and remodel the network in response to target inhibition? Furthermore, does this contribute to the emergence of drug resistance? Acquired drug resistance through remodeling of signaling pathways is frequently encountered in cancer therapy ,45 and oWhen combining drugs acting on targets with close network proximity, the inhibition of three or more of these targets seems to be required to prevent the emergence of resistance . DespiteWe have presented a systematic, large-scale comparison of 321 topological, community and graphical network parameters for a fully connected interactome of 13,345 proteins and almost 90,000 interactions, totaling 4.2 million calculated properties. We identified significant differences in the network environments that are occupied by cancer-drug targets, non-cancer-drug targets, and the overall interactome. We found a major difference between the degree of cancer-drug targets which tend to have a greater number of first neighbors and be more hub-like, and the degree of non-cancer-drug targets, which, have fewer first neighbors than the interactome average. We found that cancer-drug targets tend to communicate both within and across network communities unlike non-cancer-drug targets that primarily communicate within their communities. Overall, community behavior and subgraph connectivities played the most significant roles in this distinction. Indeed it takes a complex interplay of topological, graphical and community behaviors to provide discriminatory signatures that can distinguish cancer-drug targets from non-cancer-drug targets and from the interactome as a whole. These signatures led to the generation of predictive models that predict druggable network nodes and neighborhoods with an average accuracy of 83%.https://cansar.icr.ac.uk). These models are already useful predictive tools, the predictive power of which can only improve with the elucidation of the full human interactome and the mapping of disease-specific temporal interactions.As well as identifying targets of approved drugs, the network druggability prediction models described here identified both potentially druggable targets and target local neighborhoods, providing an independent and complementary method of assessing the suitability of a target for therapeutic modulation. The methods presented in this study use only network parameters and the training sets include targets of all approved therapeutics and not just small molecule drugs. Despite this, the output of our network models showed strong concordance with the output from other orthogonal methods that use 3D structural information or ligand binding data to predict druggability. To enable the research community to use our methodologies for objective and independent target prioritization, we have provided the results of our network-based predictions alongside structure-based and ligand-based druggability results within the canSAR website , and structurally-determined complexes from the Protein Data Bank [Data imbalance, redundancy and lack of clear quality measures are all problems in defining the human interactome ,31. The ata Bank . We remoata Bank . In ordeata Bank .We have defined a number of target/protein classes. Firstly, the positive ‘drug target list’ is a list of manually-curated targets of FDA-approved pharmaceuticals ,34, defi−6 and at least 30% sequence overlap reducing the drug target training set from 343 to 246 targets, 2) we clustered targets based on the Anatomical Therapeutic Chemical Classification System (ATC) level-3 therapeutic/pharmacological subgroups, reducing the drug target training set to 82, and 3) we clustered the targets based on shared chemical scaffolds using Bemis and Murcko [Additionally, we created non-redundant representatives of the training sets: 1) we clustered targets based on sequence similarity using a sequence identify cut-off of 50%; BLAST  E-value d Murcko  frameworWe calculated a total of 321 properties that fell into three categories: topological, graph-based and community based features  general druggability (the likelihood of a protein to be a drug target for any therapeutic area); 2) cancer druggability (the likelihood of a protein to be a cancer-drug target); 2) non-cancer druggablity (the likelihood of a protein to be a drug target for a non-cancer therapeutic area); and finally 4) cancer-association (the likelihood of a protein to be a cancer-associated protein). Predictive modeling of network data poses an interesting problem when it comes to training the model. The standard is to report the results of a k-fold cross-validation (CV). For example in 10-fold CV, the data are split into training and validation sets and the model is built using the 90% training subset and validated on the 10% subset. This process is repeated 10 times and the average accuracy of the validation is reported as the prediction accuracy. This method is widely adopted as it approximates how the model will perform on new, unseen data. However, with a network, each instance is dependent on other instances as the descriptors are based on the instance’s position in the network. Consequently, using a holdout-set is nonsensical, as there can be no new cases without generating the network data again. To overcome this problem with the 10-fold CV, we recreated random training sets that maintained the structure of the network and the number of positives, but where the positives were allocated to random proteins. We carried out a 10-fold CV on these random sets to compare to the predictive results observed from the true training sets. Another problem for the predictive modeling of the network was the imbalance of the data. The minority classes ranged from 1% to 5% and therefore regression models were built rather than 2-class classification models. As our data comprises only PU data sets, we report the results based on a ranked evaluation of area under the curve (AUC). We ranked the predictions according to their average regression output and calculated the percentile, for example, a score of 78% means that 78% of proteins had a lower rank than this protein.https://cansar.icr.ac.uk/cansar/publications/druggable_network_neighbourhoods/There are five supplementary files provided with this document and also on the canSAR website: S1 Text(DOCX)Click here for additional data file.S1 TableThe full prediction results for 10,998 proteins using the largest Y2H-based models; model quality and AUCs for the Y2H models.(XLSX)Click here for additional data file.S2 Table(XLSX)Click here for additional data file.S1 File(ZIP)Click here for additional data file.S2 File(XLSX)Click here for additional data file.S3 File(XLSX)Click here for additional data file.


By contrast, our new data suggest that a decrease in solar activity will increase and intensify the risk of frequent flooding in coastal areas.Storm surges, leading to catastrophic coastal flooding, are amongst the most feared natural hazards due to the high population densities and economic importance of littoral areas. Using the Central Mediterranean Sea as a model system, we provide strong evidence for enhanced periods of storminess leading to coastal flooding during the last 4500 years. We show that long-term correlations can be drawn between storminess and solar activity, acting on cycles of around 2200-yr and 230-yr. We also find that phases of increased storms and coastal flooding have impacted upon mid- to late Holocene agricultural activity on the Adriatic coast. Based on the general trend observed during the second half of the 20 There is a growing interest in predicting extreme weather and climate events152), representing less than 12% of the surface area. This population at risk, that grew from 95 million in 1979 to 143 million in 2000, could reach 174 million by 202513Focusing on the densely populated Mediterranean countries, more than a third of the total population lives in coastal areas and on deltas  as this zone corresponds to one of southern Europe’s key tourism and recreational areas, and is a major maritime route for the transport of goods to central and southeastern Europe. Furthermore, the CMS is considered to be a hotspot of global climate change15storm surges) and follow basin-wide oscillations (termed seiches)acqua alta, literally “high water”). These high-water events are primarily caused by enhanced south-easterly winds blowing over the shallow sea concurrently with a pronounced air-pressure gradient across the CMS. While, over most of the Adriatic basin, this south-easterly wind always prevails, there is a tendency for a strong Bora (“Dark Bora”) to occur before the peak of the surge, being replaced by the Sirocco during the most intense phase of the event2123seiche also contribute considerably to the high-water events20In the CMS, the strongest south-easterly and northeastern winds, respectively the Sirocco and the Bora, strike the long semi-enclosed Adriatic basin from autumn to spring121214C dates of short-lived terrestrial samples .Terrestrial and marine biological indicators, used as proxies for storminess during the last 4500 years, were extracted from a 720-cm continuous core  drilled on the delta of the Mirna River (Gulf of Venice) in coastal Croatia . The chrStorminess was reconstructed using three independent biological proxies: pollen-based terrestrial ecosystems, ostracods and dinoflagellate cysts . While i284backshore scrubs pollen-derived vegetation pattern  is positively correlated  with the PCA-Axis1ostra scores  and coastal (+0.38) ostracod assemblages in positive deviations . The three signals  are correlated and defined as periods when sea floods penetrated inland  has defined a rn PdVP;  and S2, viations . The PCAd inland .Coastal environment, Inputs of freshwater and Storm cluster; Coastal environment (−0.015) and Inputs of freshwater (−0.208), whereas positive scores are only loaded by the Storm cluster (0.978). PCA-Axes 2 and 3 account for 16.34% and 6.60% of total inertia, respectively.Storm activity  in the Adriatic Sea was reconstructed using three defined patterns , with peaks and intermediate periods of low activity . The ampWhen compared with the extreme hydrological events diagnosed in fluvial stratigraphy in southern Italy3840Three main periodicities elucidated in the storm signal are centered on 450-yr, 740-yr and ~2200-yr. These cycles are confirmed by the Lomb periodogram and the scalogram, corrected by the REDFIT spectral analysis . Three e10Be production rates)46The periodicity of storm activity and coastal flooding closely mirrors that of solar activity  reconstragro-pastoral activitiesPdVP was elaborated using anthropogenic indicators  and is also negatively correlated with the freshwater plantsPdVP . This suggests that low storm activity and enhanced freshwater inputs in the delta have favoured arboriculture and agriculture. Inversely, periods of higher storm surges, which generated the intrusion of saline water into the freshwater-fed plains and into the groundwater table, led to severe agricultural losses. This assumption is strengthened by the Kernel density map, which shows that anthropogenic activities are mainly concentrated during periods of low storm activity .To evaluate the agricultural losses that may arise from coastal flooding by storm events, an dicators . We compdicators . The PCAactivity . The cycactivity . The comactivity , shows tDuring the last 4500 years, extremely high-surge events happened during six periods , causinget al.Focusing on long-term trends, the storm activity and coastal flooding shows important similarities with solar periodicities  and seemth centuryOur data, focused on long-term trends of severe storms that led to flooding , suggestth November 1966 and 1st December 2008−1 as the maximum wind speed in each case. The maximum 10-minute wind speed at 35 m above ground level reached 30.1 m/s−1 in 2008−1 offshore) in November 1966 and towards the east (20.3 m/s−1 offshore) in 2008th century CE in the CMS, the strongest events seem to be linked with low solar radiation and low/negative scores of the NAO. The mechanisms behind this process must be further investigated to establish the context for such occurrences and their aftermaths during solar minima.These assumptions are supported by the severe storm surges that led to disastrous floods in Italy and Croatiath century CE59st century, severe storm activity could be one of the dominant contributors to extreme flooding events and increased losses caused by natural disasters in the Mediterranean, contrasting with the scenarios proposed by climate modelsDuring the last five millennia, our data suggest that storm activity in the CMS occurred with various severities, differentially impacting coastal agriculture. For the near future, because urbanization rates and population growth in coastal areas already surpass the hinterland, mainly driven by rapid economic development3 and percentages). Ostracods (Crustacea) were extracted from the same samples as the pollen and dinoflagellate cysts in order to avoid any analytical bias. The ostracofauna was picked from the sand fraction of the washed sediment (≤2 mm to ≥50 μm). On the basis of the species ecology outlined by LachenalSamples were prepared for pollen analysis using the standard procedure for clay samples. Pollen frequencies (percentages) are based on the terrestrial pollen sum, excluding local hygrophytes and spores of non-vascular cryptogams. Aquatic taxa frequencies were calculated by adding the local hygrophytes-hydrophytes to the terrestrial pollen sum. The aquatic taxa scores, which attest to freshwater inputs onto the delta, were calculated by summing the local hygrophytes and hydrophytes. Dinoflagellate cysts (resting stage of marine plankton) were counted on pollen-slides and are displayed as concentrations , shown as boxplots , performed on terrestrial and marine ecosystems , was implemented to generate a storm assemblage , which has been plotted on a linear age-scale. The same process was used for the ostracod time-series and a PCA-Axis1 (term PCA-Axis1ostra) was established . The LDCC assesses the time alignment of two time-series by means of the correlation coefficient. The series have been cross-correlated to ascertain the best temporal match and the potential lag between the two. The correlation coefficient is then plotted as a function of the alignment position . The PCA-Axis1pollen, PCA-Axis1ostra and dinoflagellate cyst time-series have been plotted using a LOESS smoothing (with bootstrap and smooth 0.05) on a linear age-scale  was performed to test the ordination of terrestrial ecosystems by assessing major changes in the PdVP . The “cuablished . The relposition . Positivge-scale .The three defined patterns  were finally used to run a final PCA in order to reconstruct storm activity  in the Adriatic Sea. The resulting PCA-Axis 1 was plotted on a linear age-scale with a polynomial fitting curve and a matrix plot  .10Be, ∆Total Solar Irradiance and sunspot numbers)4243The periodicity of the storm signal  was invevalue, based on an F test, gives the significance of the fit), in combination with spectral analysis. The larger (2200-yr) and the shorter (230-yr) periodicities were selected to highlight the long-term trends in solar activity4243Sinusoidal regressions were finally used in order to model periodicities in the time-series  and a Kernel density map, with Gaussian as the Kernel function (Radius 1.078)  . The pers 1.078) . A reguls 1.078) . A sinusm surges .PdVP shown as LOESS smoothing (with bootstrap and smooth 0.05) plotted on a linear age-scale. The relationship between the PCA-Axis1 and the freshwater plants was analysed using LDCC .


Data on the potential influence of macroeconomic recessions on maternal diseases during pregnancy are scarce. We aimed to assess potential change in prevalence of pregnancy-induced hypertensive disorders  during the first years of the major national economic recession in Iceland, which started abruptly in October 2008.Women whose pregnancies resulted in live singleton births in Iceland in 2005–2012 constituted the study population . Data on pregnancy-induced hypertensive disorders were obtained from the Icelandic Medical Birth Register and use of antihypertensive drugs during pregnancy, including β-blockers and calcium channel blockers, from the Icelandic Medicines Register. With the pre-collapse period as reference, we used logistic regression analysis to assess change in pregnancy-induced hypertensive disorders and use of antihypertensives during the first four years after the economic collapse, adjusting for demographic and pregnancy characteristics, taking aggregate economic indicators into account. Compared with the pre-collapse period, we observed an increased prevalence of gestational hypertension in the first year following the economic collapse  but not in the subsequent years. The association disappeared completely when we adjusted for aggregate unemployment rate . Similarly, there was an increase in prescription fills of β-blockers in the first year following the collapse , which disappeared after adjusting for aggregate unemployment rate . No changes were observed for preeclampsia or use of calcium channel blockers between the pre- and post-collapse periods.Our data suggest a transient increased risk of gestational hypertension and use of β-blockers among pregnant women in Iceland in the first and most severe year of the national economic recession. Pregnancy-induced hypertensive disorders, including preeclampsia and gestational hypertension, are significant sources of maternal, foetal and neonatal morbidity , 2. AnteIn the autumn 2008, Icelanders experienced a sudden national economic collapse. From being one of the richest nations in the world, the country suffered a major economic breakdown, affecting all inhabitants of Iceland in some way . Recent We hypothesized that the 2008 economic collapse in Iceland represented a stressor that might have led to a rise in the incidence of pregnancy-induced hypertensive disorders and corresponding drug use among women. Leveraging the nationwide complete registries of all births and drug utilization, we therefore set out to study whether the prevalence of pregnancy-induced hypertensive disorders and use of antihypertensive drugs during pregnancy changed following the major 2008 economic collapse in Iceland. Further, we aimed to assess whether the potential changes in hypertensive disorders and drug use during pregnancy were due to the aggregate economic conditions.th 2004 and all pregnancies from that time-point, subsequently resulting in live singleton births in Iceland between November 29th 2004 throughout December 31st 2012 . Pregnancy-induced hypertensive disorders are not diagnosed until after 20 gestational weeks and we therefore limited the cohort entry to this time-point in gestation. Information regarding gestational length were lacking from 20 pregnancies which were excluded from the study population.The study was based on individual level data from the National Medical Birth Register and Medicines Register in Iceland, linked by personal identification numbers, as well as aggregate data on economic indicators from Statistics Iceland . The MedPregnancy-induced hypertensive disorders. Medical conditions during pregnancy are registered in the Medical Birth Register according to the International Classification of Disease, 10th revision [ICD-10][ [ICD-10]. The priPrescription fills of antihypertensive drugs. As a secondary study outcome we used prescriptions fills for antihypertensive drugs. For the women included in the study, we extracted all prescriptions of β-blockers  code C07) and calcium channel blockers (ATC code C08), filled after 20 gestational weeks onwards. Substances belonging to abovementioned ATC drug codes are Labetalol and Nifedipine, which are two of the most commonly used drugs for treating hypertensive disorders during pregnancy  and infant’s sex . GestatiIn order to further capture if the potential influence of time on the outcomes was due to macroeconomic changes, we used aggregate economic indicators as the unit of analysis. The economic indicators tested were national unemployment rate and gross domestic product (GDP), as traditional measures of economic conditions. However, as the Icelandic collapse resulted in a debt crisis at the national and individual levels , we alsoWe calculated descriptive statistics for all maternal and pregnancy-related characteristics, contrasting frequencies across exposure groups. Chi-square and one-way ANOVA were used to assess differences in the distribution of maternal and pregnancy-related characteristics.th 2004, was used to address potential time-trends in the aggregate explanatory variables as well as in the prevalence of the outcome variables. The final regression models were adjusted for I) maternal age, gravidity and time-trend, II) maternal age, gravidity, time-trend, diabetes, pre-existing hypertension, relationship status, place of residence, employment status, citizenship and infant sex, III) maternal age, gravidity, time-trend and aggregate economic indicators, if associated with index outcome in a supplementary analysis. We did not adjust for seasonality in our main regression models as the exposure categories were equally balanced with respect to calendar time. However, the effect of seasonality on the outcomes of interest was explored in a supplementary analysis. Similarly, adjusting for seasonality, logistic regression models were created in order to further explore the odds ratio of gestational hypertension and prescription fills for β-blockers in months 1–6 and months 7–12 following the economic collapse, compared with the pre-collapse period.In order to examine the impact of the economic collapse on the outcome variables, we used logistic regression analyses to calculate the crude and adjusted odds ratios (ORs) and corresponding 95% confidence intervals [CIs] for each outcome contrasting the four separate post-collapse years with the pre-collapse period. The total number of calendar weeks during the study period, beginning on September 27Further, in a supplementary analysis we used logistic regression analyses to estimate the crude and adjusted ORs and corresponding 95% CIs to assess the association between each aggregate economic indicator, i.e. unemployment rate, GDP, balance of accounts, rates of either finding it very difficult making ends meet or having defaults on loans or rent, and the study outcomes irrespective of the defined exposure categories. We adjusted for all maternal and pregnancy-related covariates separately to determine which of the covariates affected the measured association. We then constructed three different regression models adjusting for i) time-trend, ii) time-trend, maternal age and gravidity and iii) time-trend, maternal age, gravidity, diabetes, pre-existing hypertension [ICD-10 code O10], relationship status, place of residence, employment status, citizenship and infant sex.All the data analyses were performed using IBM SPSS Statistic 20.The study was approved by the Icelandic National Bioethics committee (VSNb2013010002/03.07), the Data Protection Authority (2012121499HGK/—) and the Directorate of Health (1301064/5.6.1/gkg). An informed consent from women in the study population was not obtained as all personal information was anonymized and de-identified prior to analysis.The overall prevalence of pregnancy-induced hypertensive disorders remained stable during the study period. However, when gestational hypertension and preeclampsia were examined separately, an increase was observed for gestational hypertension from 2.1%  to 2.6% , while the prevalence of preeclampsia decreased from 3.8%  to 3.2%  . During After adjusting for time-trend and other available covariates, we observed increased odds of pregnancy-induced hypertensive disorders (aOR = 1.03 [1.00–1.06]), gestational hypertension  and prescription fills for β-blockers  with each percentage point increase in unemployment . Unemployear 1 = 1.47, 95% CI [1.13–1.91]), as compared with the pre-collapse period  when adding aggregate unemployment rate to the model. We found no association between the economic collapse and gestational hypertension during the subsequent post-collapse years or with overall pregnancy-induced hypertensive disorders or preeclampsia during any of the post-collapse years ; an increase which disappeared when adjusting for aggregate unemployment rate   .In this nationwide study of women with live singleton births in Iceland during a time of severe economic fluctuation, we observed a transient increase in the risk of gestational hypertension and prescription fills for β-blockers during the first year following the economic collapse, but no such increase was detected for preeclampsia. In parallel with the development of the macroeconomic conditions, this initial increase in gestational hypertension seemed to level off with years passing from the severe economic collapse. Indeed, our findings suggest that the increase risk of gestational hypertension at the first year of the crisis may be explained by changing aggregate unemployment rates, reflecting the severity of the economic crisis at this time point.The dramatic economic collapse in Iceland in 2008 affected the whole Icelandic population in one way or another and recent studies suggest considerable influence on mental health –19 and rThe pathways through which stress could affect pregnancy-induced hypertensive disorders are not fully understood. Stress can influence health behaviours of affected individuals to the worse, resulting in higher levels of smoking, less exercise and poorer diet . In addiIt is unclear why we observed an association between the economic collapse and gestational hypertension but not to preeclampsia, yet two explanations seem most plausible. Firstly, if viewed as separate diseases with different aetiologies, it is possible that mechanisms underlying gestational hypertension are more sensitive to stress compared with mechanisms underlying preeclampsia. Secondly, from the perspective that the gestational hypertension is merely a milder form of preeclampsia, it is possible that the economic collapse was not a stressor of sufficient magnitude to cause the more severe form of the disorder.The β-blocking agent Labetalol is the first line of treatment of pregnancy-induced hypertensive disorders in Iceland. In most cases the calcium channel blocker, Nifedipine, is prescribed if treatment with Labetalol has proven insufficient or is not tolerated by the pregnant woman. However, during the last 10 years, Nifedipine has increasingly been used for treatment of contractions during pregnancy, which might explain the time-trend observed for calcium channel blockers in our study.The available data in our study are not informative on potential underlying mechanisms although they suggest that the influence of this societal stressor on pregnancy-induced hypertensive disorders was rapid and transient, although further exploitation of the time during the first year following the collapse did not reveal much difference of the effect between women who were pregnant in the first and second half-year after the collapse. The observed increase in gestational hypertension and in prescription fills for β-blockers in the first year following the economic collapse disappeared entirely when we adjusted for the aggregate unemployment level. This finding is supported by a line of studies linking pregnancy-induced hypertensive disorders, particularly preeclampsia, to socioeconomic difficulties –35. To oThis study leverages the National Medical Birth Register and Medicines Register in Iceland to accomplish a population based cohort study of all pregnancies resulting in live singleton births in Iceland during eight years of follow-up. These registries are a rich source of information regarding health and drug use of pregnant women and their offspring, enabling collection of data independent of the exposure categories, i.e. timing of the economic collapse. The detailed information in the Medical Birth Register allowed us to account for potential confounding factors. In order to enhance internal validity of the study, we restricted the study population to singleton pregnancies as previous studies indicate higher risk of hypertensive disorders in multiple pregnancies. Furthermore, we adjusted for potential time-trend in the study outcomes in the statistical analyses. Thus, the observed increase in gestational hypertension and prescription fills for β-blockers is unlikely to be explained by secular trends in the detection rate of the diseases or prescribing practices among health care professionals in Iceland.A limitation of this study is the lack of accessible data on smoking, body mass index and other behavioral factors that might possibly influence the observed increase in gestational hypertension. Many of these behavioral risk factors are strongly associated with pregnancy-induced hypertensive disorders, although some in opposite direction . A suddeIn summary, the results suggest a transient increase in gestational hypertension and use of β-blockers among pregnant women in Iceland in the first year following the national economic collapse. The severity of the aggregate economic climate at that time with a gradual yet slow recovery during the following years is a likely explanation for the observed pattern.S1 Appendixth 2004 and December 31st 2012.The association between aggregate macroeconomic indicators in Iceland and (A) overall pregnancy-induced hypertensive disorders, (B) gestational hypertension, (C) preeclampsia, (D) prescription fills for β-blockers, (E) prescription fills for calcium channel blockers, among the women in the study population giving birth to live born singletons between November 29(DOCX)Click here for additional data file.S2 AppendixThe odds ratios [OR] and 95% confidence intervals [CI] of (A) overall pregnancy-induced hypertensive disorders, (B) gestational hypertension and (C) preeclampsia in each of the four post-collapse years following the economic collapse in Iceland compared with pre-collapse period, adjusted for seasonality.(DOCX)Click here for additional data file.S3 AppendixThe odds ratios [OR] and 95% confidence intervals [CI] of (A) prescription fills for β-blockers and (B) prescription fills for calcium channel blockers in pregnancies during each of the four post-collapse years following the economic collapse in Iceland compared with pre-collapse period, adjusted for seasonality.(DOCX)Click here for additional data file.S4 AppendixThe odds ratios [OR] and 95% confidence intervals [CI] of (A) gestational hypertension and (B) β-blockers in the first and second half year following the economic collapse in Iceland compared with pre-collapse period(DOCX)Click here for additional data file.


Traditionally, acute undisplaced or minimally-displaced scaphoid fractures are treated by casting in short- or long-arm casts. Although reports have shown that operative treatment is safe, effective and produces satisfactory results, outcomes from current studies comparing these two methods are questionable. The aim of this meta-analysis was to evaluate the effects of operative versus non-operative treatment for acute undisplaced or minimally-displaced scaphoid fractures in adults.Computerized searches were performed without language restrictions and all randomized controlled studies providing information on the effects of operative versus non-operative treatment on the outcomes of acute undisplaced or minimally-displaced scaphoid fractures were included. The weighted and standard mean difference (WMD and SMD) or the relative risk (RR) were calculated for continuous or dichotomous data respectively.A total of six studies reported in seven publications were included, representing data on 340 fractures. Meta-analysis indicated that operative treatment resulted in significantly better functional outcomes in the short term when compared with non-operative treatment. Consistently, patients who accepted surgery had a more rapid return to work. Further, surgery was advantageous in preventing delayed union of the fractures, a finding supported by the results of analysis of the time to fracture union. A number-needed-to-treat analysis revealed that more than 20 patients would have to undergo operative treatment to prevent one delayed union.Acute undisplaced or minimally-displaced scaphoid fractures demonstrate faster recovery with operative treatment; however, the current meta-analysis does not provide evidence supporting the routine use of operative treatment for all acute undisplaced or minimally-displaced scaphoid fractures. Traditionally, undisplaced, stable scaphoid fractures are treated by casting in short- or long-arm casts. Cast immobilization always involves prolonged immobilization of at least 12 weeks. ClearlyRecently, a few randomized controlled trials (RCTs) regarding operative versus non-operative treatment in the management of acute undisplaced or minimally-displaced scaphoid fractures have been published. However, the relatively small sample size n = 25–88) in each published study rendered the results inconclusive and controversial. Recently, a meta-analyses of RCTs compared the effectiveness of surgical versus non-surgical treatment of acute undisplaced or minimally-displaced scaphoid fractures8 in each, which wThe aim of the current meta-analysis was to investigate the outcomes of operative treatment for minimally-displaced and undisplaced scaphoid fractures compared with non-operative treatment; furthermore, we also attempted to illuminate the limitations of current studies and to provide suggestions for further studies to evaluate these therapeutic options for the treatment of acute scaphoid fractures.We performed this meta-analysis following the guidelines of the PRISMA statement. ComputeAll identified studies were reviewed by all of the authors and information was carefully extracted independently by two reviewers (LS and JT); Any disagreements between the authors were resolved by discussion to reach a consensus. The quality of included RCTs was evaluated using the Jadad scale, with a score less than 3 being indicative of low quality. The risP value or confidence interval (CI) using the method described in the Cochrane Handbook for Systematic Reviews of Interventions for conversion [From the selected articles, data extracted comprised: (a) the functional outcome, which was the primary outcome, measured using the Patient Evaluation Measure, a modified Green/O'Brien score and Patient-Related Wrist Evaluation (PRWE), (b) the range of motion (ROM), grip and pinch strength, (c) duration of absence from work and (d) final complications and time to fracture union. We sent an e-mail to each corresponding author of the included studies in an attempt to obtain the original data. In some instances standard deviations (SDs) were not presented; we calculated these from the nversion .a priori, and the random effects model was used in all the analyses. A sensitivity analysis was performed by investigating the effect of each individual study on the pooled effect size. Funnel plots were used to assess possible publication bias. Because of the limited data available from each RCT for the pooled analysis, we did not perform subgroup analysis based on the treatment methods, for example, percutaneous or open screw fixation, short- or long-arm cast. A P-value less than 0.05 was considered statistically significant. Analyses were performed using the Stata/SE 10.0 program (Stata Corporation).The data at the same time points of follow-up were pooled. For the meta-analysis of continuous variables using the same scales, the weighted mean difference (WMD) with a 95% CI was used, while the standardized mean difference (SMD) with a 95% CI was used for continuous variables using different scales, for example, function scores with different measurement scales. For dichotomous variables, the relative treatment effect was expressed as relative risk (RR) with a 95% CI. We anticipated the presence of clinical heterogeneity, based on the facts that fixation methods, surgical approach and cast immobilization varied among the RCTs. Because the test for heterogeneity had low statistical power, the presence of heterogeneity was assumed et al.[The analysis yielded a total of six articles eligible for analysis ,17,18,19et al. providedet al.. The twoThe quality of each study was graded and scored from 2 to 4 according to the Jadad scoring system. Sample Analysis of functional scores from two studies,16 showeOf the six studies, three contained continuous data on ROM. No ROM variables revealed any significant differences in treatment effect at 2, 3, 6, or 12 months or more than 1y .Pooled data across two or three studies at 2, 3, 6, and 12 months’ follow-up demonstrated that those patients who underwent operative treatment had significantly greater grip strength than those who received non-operative treatment. . HoweverP < 0.001)  .P = 0.75) in six studies , with a 74.6% reduction  in risk when compared with non-operative treatment (P < 0.001)  . Meta-an< 0.001) .P = 0.71, Sensitivity analysis and publication bias analysis was performed for the overall populations using the rate of incidence of overall complications. The evaluation regarding the influence of each study on the overall RR revealed that no individual study had a dominant effect on the overall RR, since omission of any single study did not make a large difference . MoreoveThere was a wide range of follow-up term and a great deal of variation in the outcome measurements used across the included RCTs, with three of the six studies regarded as notably poor quality,18,19. TOur results revealed that surgical treatment leads to a significantly better functional score in the early stages (2 and 3 months) after fracture fixation. One possible explanation is that screw fixation is more reliable and therefore achieves adequate stability and allows early wrist mobilization, leading to improved strength. This theory is supported by the grip strength outcomes in our analysis, with the operative treatment group showing significantly better grip strength than the non-operative treatment group from 2 months after fixation, an advantage which continued up to 12 months. Since better functional outcomes can be achieved in the short-term with screw fixation, operative treatment should be considered for patients who require a fast restoration of function. Consistent with these explanations, as shown in our study, patients treated surgically had a more rapid return to work compared with those managed non-surgically, based on the data regarding duration of absence from work.Our meta-analysis demonstrated no statistically-significant difference between operative and non-operative treatment with regard to total complications. However, independent analysis showed that operative treatment had the advantage with regard to delayed union, which is supported by the analysis based on time to fracture union. Our findings contribute to the growing body of evidence that primary surgical treatment is a reliable method of reducing the risk of delayed union after acute undisplaced or minimally-displaced scaphoid fractures. However, a number-needed-to-treat analysis revealed that more than 20 patients would have to undergo operative treatment to prevent a single delayed union. Routine screw fixation would therefore expose an unacceptably high number of patients to the risks of surgery, especially when another meta-analysis as well et al.[et al.[Our meta-analysis has some limitations. The first limitation is that the sample size of each included study is small because of the difficulties of performing clinical trials in surgery, and given the small difference in outcomes such as nonunion and malunion, even the results from our pooled analysis are probably underpowered. The second limitation is that the effects of age on the outcomes of operative and non-operative treatment were not estimated in our analysis, due to the lack of data regarding this aspect in the included RCTs. In contrast to classical teaching, scaphoid fractures do occur even in the elderly population, and eldet al. revealedl.[et al. comparedl.[et al. and reveDespite the limitations, we believe that this meta-analysis offers useful conclusions based on the published RCTs. In the management of acute undisplaced or minimally-displaced scaphoid fractures, patients who were treated surgically recovered more quickly than did patients who were treated non-surgically. Our data also indicate that the literature does not provide evidence supporting the routine use of operative treatment for all acute undisplaced or minimally-displaced scaphoid fractures.In future clinical studies, researchers should design the protocol carefully, compare the effects of operative versus non-operative treatment in large multicenter trials that include both young and old patients with different types of fractures, and perform parallel economic analysis to obtain robust and comprehensive results.S1 File(DOC)Click here for additional data file.S2 File(DOC)Click here for additional data file.


Both young and middle-aged subjects showed increased errors and reaction times while performing under dual-task conditions and both outcome measures increased further under fatiguing conditions. Only under 30%-dual-task demands, an age-effect on dual-task performance was present. Both single- and dual-task conditions showed that already at mid-life response preparation is seriously declined and that subjects implement different strategies to perform a CRT task.Generalized slowing characterizes aging and there is some evidence to suggest that this slowing already starts at midlife. This study aims to assess reaction time changes while performing a concurrent low-force and high-force motor task in young and middle-aged subjects. The high-force motor task is designed to induce muscle fatigue and thereby progressively increase the attentional demands. Twenty-five young  and 16 middle-aged  adults performed an auditory two-choice reaction time task (CRT) with and without a concurrent low- or high-force motor task. The CRT required subjects to respond to two different stimuli that occurred with a probability of 70 or 30%. The motor task consisted of index finger abduction, at either 10%  or 30%  of maximal voluntary force. Cognitive task performance was measured as percentage of correct responses and reaction times. Middle-aged subjects responded slower on the  With increasing age cognitive performance slows down , includiPrevious studies in our group on young subjects showed a decline in performance on a cognitive task during a concurrently performed motor task, and additionally that the decline became stronger when the motor task was fatiguing . In thosIn our cognitive-motor dual-task , we usedPrevious reaction time studies showed that older subjects choose to maintain accuracy over speed in a dual-task condition . It is, Most experiments have been performed on young (<35 years) and older subjects (>65 years). Neuroimaging studies, however, indicate that age-related changes can already appear in late midlife . WhetherTherefore, it was the aim of the present study to investigate differences in response preparation and dual-task costs in young and middle-aged adults. Furthermore, we induced muscle fatigue during the dual-task to further increase the attentional load and to evoke additional dual-task interference in both young and middle-aged adults. We expected less response preparation and more dual task costs in middle-aged subjects. Furthermore, we expected the motor task to be performed adequately in both age groups, with only little dual-task costs on the motor task . Howeverp = 0.20). All participants gave their informed consent before participation. The study was approved by the University Medical Center Groningen medical ethical committee and was in conformance with the standard set out in the We used data obtained in 25 young  and 16 middle-aged  adults. All subjects were right-handed according to the Edinburgh Handedness Questionnaire  or a high (900 Hz) pitched tone at a level of 70 dBA. The tones were of 50 ms duration with an inter-stimulus interval of 1100–1300 ms. The participants were instructed to respond as quickly and as accurately as possible by pressing a button on a serial response box with their left index or middle finger. E-Prime software was used to present the stimuli and record the responses . The expected response (index- or middle finger) to high and low tones was randomized between participants. The probability of one of the tones was more frequent (70%) than the other tone (30%). Which tone was presented more frequent was randomized between participants. Participants were informed that the first stimulus of every block was always the frequent stimulus.Figures 1 and 2. Each session consisted of four tasks:Participants came for three sessions, separated by 1 week. The first session was a practice session. All tasks were practiced in order to familiarize participants with the task and to minimize learning effects in the cognitive task. Some of the tasks were performed with fewer blocks in the practice session compared to the second and third session. In the second and third session, a dual-task at either 10 or 30% of maximal voluntary contraction (MVC) was performed. For an overview of the tasks, see Practice of CRT. Responding to 150 stimuli (Task Ia), followed by three blocks of 50 stimuli, with 5 s between the blocks (Task Ib). The purpose of the practice tasks was to minimize the within-session learning effect.Determination of MVC. Participants were asked to maximally abduct their right index finger three times for 5 s, with 60 s of rest between attempts. The maximal force of the three attempts was taken as the control MVC (cMVC), the mean rectified EMG (100 ms) around the peak force was used as the control EMG (cEMG).Single-task. Twelve blocks of the CRT consisting of 33 stimuli (~40 s blocks). After the first, third, sixth, ninth, and twelfth block, subjects were instructed to perform a 5 s MVC with their right FDI to acquaint subjects with the timing of the MVCs during the dual-task.Dual task. Task consists of a combination of the force and CRT task. Participants were instructed to maintain a stable force level at either 10 or 30% of their cMVC in that session. All subjects were instructed to prioritize the motor task over the cognitive task in order to standardize the dual task performance. Four seconds into the force-task, the cognitive stimuli started and subjects had to respond to the stimuli with their left hand while still abducting their right index finger. Similar to the CRT (single-task), blocks of 33 stimuli were presented. After the CRT task ended, participants were asked to perform an MVC during 5 s, followed by 5 s rest. This task sequence continued for 12 blocks for the 10%-dual-task, and until task failure for the 30%-dual-task . Task failure was defined as a subject being unable to maintain the force at 30% for more than 5 s, or when the MVC did not exceed 30%.The main outcome measures during task II were the MVC and the maximal rectified and smoothed (100 ms) EMG. During the dual-task (task IV), mean submaximal force (% of cMVC), variability (SD) of the submaximal force, mean rectified EMG activity (% of cEMG) and MVCs (% of cMVC) were determined. Cognitive outcome measures consisted of the percentage of incorrect responses and the reaction times. The first two responses of each block were discarded because participants were informed that the first tone was always the frequent tone. Responses faster than 100 ms were counted as incorrect. Only reaction times to correct responses were used in the analyses. In order to minimize the influence of outliers, 20% trimmed means were used to assess mean reaction time values per subject, i.e., the slowest and fastest 10% of reactions on each task per subject were removed from the analysis.In order to investigate within-session training effects, repeated measures ANOVAs were performed with Task  and Probability  as within-subjects effects and Age group as between-subjects effects. To investigate between-session learning effects, we used the cognitive data obtained during the single CRT task. For all sessions only the first six blocks were used since the practice session consisted of six blocks only. Repeated measures ANOVAs were performed with Session and Probability as within-subjects effects and Age group as between-subjects effects. If the assumption of sphericity was not met, degrees of freedom were Greenhouse-Geisser-corrected.The MVCs between groups were tested with a univariate ANOVA with Age group and Sex as factors; Sex was added as a between-subjects variable since it is known that men are stronger than women.For comparison of the single- versus the dual-task performance, we used cognitive data from 12 blocks of both the single- and the 10%-dual-task. To investigate the effect of fatigue we compared the data obtained during the 10- and 30%-dual-task. The data was averaged for two time windows: the first and second half of the task. Both the cognitive and the force-related data obtained during the 10%-dual-task were averaged for the same number of blocks as for the 30%-dual-task. This was not possible for one middle-aged and two young participants, who maintained the 30%-dual-task for 13 and 15 blocks. For these participants, 12 blocks of the 10%-dual-task were used. Four young participants maintained the dual-task for only three blocks. In order to obtain a reliable estimate for the reaction time and accuracy data, the second block of data was used to calculate results for both the first (=average block 1 and 2) and second (=average block 2 and 3) part of the task. Force data was examined with repeated measures ANOVA with Task  and Time  as within-subjects factors and Age group as between-subjects factor.Cognitive data was examined with repeated measures ANOVA with Task and Probability as within-subjects factors, and Age group as a between-subjects factor. For comparison of the 10%-dual-task with the 30%-dual-task, Time  was added as a within-subjects factor. For comparison of the 10%- versus the 30%-dual-task, the percentage of incorrect responses and reaction times of both dual-tasks were represented as the delta of the dual-task minus the single-task. These analyses were performed separately for both outcome measures; that is, percentage of incorrect responses and reaction times.factor/SStotal). If interaction effects were present, main effects were not explicitly described. Post hoc analyses  were performed to break down significant effects where appropriate.Statistical significance was set at alpha is 0.05, effect sizes are reported as η = SQRT. Analysis revealed no training effects within a session for accuracy  or reaction times . Furthermore, no training effects were observed on accuracy between sessions . For reaction times, an interaction effect of Session by Probability was present . Post hoc analyses showed that for frequent stimuli, reactions became faster from Session 1 (315 ms) to Session 2 , and from Session 2 to Session 3 . For infrequent stimuli, reaction times decreased only from Session 1 (351 ms) to Session 2 . The difference in reaction times and number of errors between frequent and infrequent stimuli were present in all sessions with faster reactions and less errors for frequent stimuli . Overall, subjects were responding faster and more accurate to frequent stimuli, suggesting the presence of preparation.We used the data obtained during the cognitive single-task in the three sessions to ascertain possible differences in training effects between the two age groups  and reaction times . Post hoc analysis showed for the infrequent stimuli a higher number of errors for young subjects , but not for the frequent stimuli . In contrast, the reaction times for frequent stimuli were higher for middle-aged subjects , but not for the infrequent stimuli . Both middle-aged and young participants made more errors  and responded slower  on the infrequent stimuli compared to the frequent stimuli . Overall, middle-aged subjects made less errors  but responded slower .Besides main effects, the analysis revealed an interaction effect of Probability by Age group for accuracy  and reaction times . Although an increase in errors was present from the single- to the dual-task for both the frequent  and infrequent stimuli , the increase was larger for the infrequent stimuli. Reaction times were also longer for the infrequent stimuli in the dual- versus the single-task , but not for the frequent stimuli .The data showed an interaction effect of Task by Probability for accuracy  and were slower  on the infrequent stimuli compared to the frequent stimuli . Overall, the single versus dual task data demonstrated that in both tasks, young subjects responded faster to the frequent stimuli but made more errors on the infrequent stimuli than middle-aged participants did, suggesting that young subjects prepared themselves better for the frequent stimuli. The more demanding dual-task resulted in slower responses and more errors for the infrequent stimuli, without changes in reaction times for the frequent stimuli.In both the single- and the dual-task, participants made more errors (p = 0.66). Furthermore, no difference was found in MVCs between young  and middle-aged participants . Men were, however, stronger than women , but no interaction effect of Age group by Sex was present . The number of blocks until fatigue (task failure) did not differ between young and middle-aged participants .The maximal index finger force at the start of the session was not different in the 10- and 30%-dual task session . No differences were found on the 10%-dual-task .Middle-aged participants produced marginally less force during the 30%-dual-task (mean force: 30% of cMVC) than young participants did , but no main effect of Age group was present .During the 30%-dual-task the intermittent MVCs declined more (33%) than during the 10%-dual-task . No main effect of Age group was present .The standard deviation of force during the dual-task showed a stronger increase with time during the 30%-dual task (0.02% of MVC) than during the 10%-dual-task . No main effect of Age group was present .The EMG increased more with time in the 30%-dual-task (with 13.1%) compared to the 10%-dual-task .F1,39 = 3.80, p = 0.06, η = 0.08) and a significant interaction for reaction times . With time, an increase was seen in number of errors and reaction times for the 30%-dual-task , but not in the 10%-dual-task .In the comparison between the 10 and 30%-dual-task, we found a trend toward an interaction effect of Task by Time for accuracy .Slower responses  and more errors  were made in the 30%- compared to the 10%-dual-task . An increase in errors between the 10- and 30%-dual-task was present for both frequent  and infrequent stimuli , the increase being larger for the infrequent stimuli.For accuracy, we found an additional interaction effect of Task by Probability  shows that dual-task demands were greater for the middle-aged than the young participants.A main effect of Age group for reaction times (n = 7130), There are indications that sex has an effect on motor  and dualF1,38 = 0.10, p = 0.75; 10%-dual-task: 3.6 and 3.5%; F1,38 = 0.10, p = 0.76; 30%-dual-task: 3.6 and 2.9%; F1,38 = 0.41, p = 0.52, for men and women, respectively), nor did we find interaction effects with Sex. We did see, however, that women responded slower than men did . For the 30%-dual-task an interaction effect of Task by Sex  was found. Therefore, we decided to run the analyses on the effects of fatigue again, but separately for men and women.On the single- and dual-tasks, no difference on accuracy was found for Sex . The number of errors for the infrequent stimulus in the 30%-dual-task increased with time more for young men, as can be seen in Figure 7. For reaction times in men, an interaction effect of Task by Time was present . At the start, the reaction times for the 10- and 30%-dual-task were similar  but the reaction times increased more during the 30%-dual-task  than during the 10%-dual-task . During the dual-task, reaction times were slower for the infrequent (+15 ms) than the frequent (+7 ms) stimuli .For accuracy in men, we found an interaction effect of Task by Probability by Time by Age group . For both stimuli, the number of errors were larger in the 30%-dual-task . The difference in errors between the stimuli were, however, larger in the 30%-dual-task  than the 10%-dual-task . For reaction times in women, an interaction effect of Task by Age group was present . Middle-aged women showed slower responses than young women in the 30%-dual-task , but not in the 10%-dual-task . However, both Age groups showed an effect of dual-task force on reaction times . Thus, the increase in reaction times from a 10 to 30%-dual-task was present in both young (17 ms) and middle-aged women (46 ms), but stronger in middle-aged women.For accuracy in women, there was an interaction effect of Task by Probability  responded slower but more accurate than young subjects did; (2) were less prepared for frequent stimuli than young subjects were; (3) showed an additional increase in reaction times during the 30%-dual-task. Furthermore, both young and middle-aged subjects showed a decline in cognitive performance under dual-task compared to single-task conditions and during the fatiguing dual-task, cognitive performance showed an additional decline. This decline during fatigue was not different for middle-aged compared to young participants. Pilot analyses, however, in which the data were split for sex, showed differential effects of age for men and women on dual-task performance under fatiguing conditions.With age, cognitive tasks become increasingly more difficult to perform . Our datWe designed the cognitive task such that one stimulus had a higher probability (70%) to be presented than the other stimulus (30%). Consequently, after implicit learning subjects started to prepare for the frequent stimulus , therebyIndeed, during the practice sessions the reaction times, especially on the frequent stimuli, decreased with time, and the difference between reaction times on frequent and infrequent stimuli increased between the sessions. However, despite the training effects middle-aged subjects continued to be slower, but more accurate, than young subjects did. The age difference in reaction times was more evident in the frequent stimuli (larger difference between young and middle-aged participants for the frequent than the infrequent stimuli). On the other hand, the differences in accuracy were more evident in the infrequent stimuli (young adults making more errors than middle-aged adults did). The observed difference in reaction times between frequent and infrequent stimuli  were comparable to prior experiments .Our data confirmed literature showing a better preparation by young subjects compared to older subjects, albeit using a different approach , and extTasks become less automatic with increasing age  and espesmaller attentional reserve. Thus, the observation that middle-aged subjects prepared less for the frequent stimuli may result in a smaller or no difference in attentional reserve capacity between the two age groups. Still, during the dual-task paradigm, additional resources need to be utilized and since task performance deteriorated in both age groups, it is expected that the attentional requirements exceeded the attentional resources for both age groups; albeit for different reasons.Previous studies found mixed results during dual-task performance. Some studies found dual-task performance to decrease with increasing age , whereasThe force measures did not show an effect of age. Previous experiments also demonstrated that force of a hand muscle is relatively stable and only starts to decline at high age . With reThe data clearly showed an increase in muscle fatigue with time during the 30%-dual-task. This was illustrated by the force decline, EMG increase and increased force variability especially during the 30%-dual-task. By inducing muscle fatigue, attention needed to perform the motor task increases, as is shown in previous studies  by the sInterestingly, sex was found to affect our results. The increase in reaction times by the middle-aged women on the 30%-dual-task was the most distinct result in women. This slowness can be a result of the increase in force levels . HoweverFigure 7C). In order to maintain fast reaction times under fatiguing conditions, young men appear to prepare more, leading to more errors on the infrequent stimuli.Men showed an effect of age group on accuracy performance with increasing fatigue, but only in the 30%-dual-task on infrequent stimuli (see In summary, our results showed that age already affects cognitive performance in midlife. Especially the different strategies used by middle-aged and young adults in the reaction time task are of interest. Most of the changes are early markers of age-related changes in cognitive performance, as described by several authors for elderly subjects . With inThe authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.