349 research outputs found
Dynamic nitrogen deposition thresholds during forest stand development in a Douglas fir forest analysed with two nitrogen models SMART2 and MERLIN
In contrast to the classical critical load (CL) concept, based on long-term steady-state conditions, a dynamic deposition threshold (DDT) is introduced. This DDT takes into account all relevant dynamic aspects of vegetation development/forest growth, mineralisation, immobilisation and denitrification, depending on the successional stage of the forest. DDT values for nitrogen were determined for a Douglas fir rotation by two process-based nitrogen models SMART2 and MERLIN using three different criteria for critical nitrogen leaching. During most of the rotation time, the predicted DDT values were higher than the corresponding traditional CL. SMART2 and MERLIN predicted a maximum DDT of 4.9 and 4.6 kmol N per ha per year (69 and 64 kg N per ha per year, respectively), when accepting a critical N leaching level of 1.73 kmol N per ha per year related to impacts on ground water quality. This is due mainly to relatively high tree uptake during the first 50 years of a forest rotation, compared to a long-term estim
Drug Safety Issues Covered by Lay Media:A Cohort Study of Direct Healthcare Provider Communications Sent between 2001 and 2015 in The Netherlands
Background: Some drug safety issues communicated through direct healthcare professional communications (DHPCs) receive substantial media coverage, while others do not. Objectives: The objective of this study was to assess the extent of coverage of drug safety issues that have been communicated through DHPCs in newspapers and social media. A secondary aim was to explore which determinants may be associated with media coverage. Methods: Newspaper articles covering drug safety issues communicated through 387 DHPCs published between 2001 and 2015 were retrieved from LexisNexis Academic™. Social media postings were retrieved from Coosto™ for drugs included in 220 DHPCs published between 2010 and 2015. Coverage of DHPCs by newspapers and social media was assessed during the 2-month and 14-day time periods following issuance of the DHPC, respectively. Multivariate logistic regression was used to assess potential DHPC- and drug-related determinants of media coverage. Results: 41 (10.6%) DHPC safety issues were covered in newspaper articles. Newspaper coverage was associated with drugs without a specialist indication [adjusted odds ratio 5.32; 95% confidence interval (2.64–10.73)]. Negative associations were seen for time since market approval [3–5 years 0.30; (0.11–0.82), 6–11 years 0.18; (0.06–0.58)] and year of the DHPC [0.88; (0.81–0.96)]. In the social media, 180 (81.8%) drugs mentioned in 220 DHPCs were covered. Social media coverage was associated with drugs without a specialist indication [6.92; (1.56–30.64)], and for DHPCs communicating clinical safety issues [5.46; (2.03–14.66)]. Conclusions: Newspapers covered a small proportion of DHPC safety issues only. Most drugs mentioned in DHPCs were covered in social media. Coverage in both media were higher for drugs without a specialist indication
Comparison of model concepts for nutrient availability and soil acidity in terrestrial ecosystems
STOWA heeft het initiatief genomen om samen met een aantal partijen een klimaatrobuuste Waterwijzer Natuur (WWN) te ontwikkelen. Een instrument dat de effecten van klimaatverandering en het waterbeheer op de terrestrische vegetatie van natuurgebieden dient te kunnen berekenen. Klimaatverandering zal vooral gevolgen voor natuurlijke vegetaties hebben via veranderingen in de waterbalans. Die veranderingen werken namelijk door op de bodemtemperatuur en de hoeveelheid vocht, zuurstof en nutriënten die voor de planten in het wortelmilieu beschikbaar zijn. Klimaatverandering noopt dan ook tot het stellen van enkele essentiële vragen, zoals: Welke maatregelen zijn er nodig om natuurdoelen in de toekomst zeker te stellen? Welke alternatieve doelen kunnen we overwegen als in het verleden vastgestelde natuurdoelen niet meer haalbaar blijken te zijn onder een veranderend klimaat? Waar liggen straks, in het klimaat van de toekomst, de beste kansen voor het creëren van hotspots van biodiversiteit? Dit rapport geeft een overzicht van de overeenkomsten en verschillen van de wijze waarop PROBE (KWR) en VSD+ (WEnR) de nutriëntenbeschikbaarheid en zuurgraad in (half)natuurlijke terrestrische ecosystemen voorspellen in afhankelijkheid van milieu, (vnl. atmosferische depositie), klimaat (vnl. temperatuur en neerslag) en waterbeheerscenario’s
Factors Influencing Preferences and Responses Towards Drug Safety Communications:A Conjoint Experiment Among Hospital-Based Healthcare Professionals in the Netherlands
Introduction Healthcare professionals (HCPs) are informed about new drug safety issues through Direct Healthcare Professional Communications (DHPCs). The influence of DHPC content on the impact of the communication is unclear. Objectives The aim of this study was to assess the effect of content elements 'frequency of the safety issue', 'seriousness of the safety issue', 'need to take action', 'life span of drug involved' and 'type of evidence supporting the safety issue' on hospital-based HCPs' preferences and responses towards DHPCs. Methods A survey study including a conjoint experiment was performed among hospital-based HCPs in the Netherlands. Hypothetical DHPCs varying on the five content elements were constructed. Each respondent received eight out of 16 hypothetical DHPCs and was asked about (1) importance to be informed (fixed-point scale), (2) preferred communication timing (multiple options) and (3) their stated actions (multiple options). Associations were tested using generalized linear mixed models. Results In total, 178 HCPs participated. DHPCs concerning more frequent or serious safety issues, or requiring action, were associated with a higher perceived importance to be informed and a preference for immediate communication. Periodic communication was preferred for DPHCs concerning less frequent or serious safety issues. The most commonly stated action was to discuss the DHPC with colleagues. Monitoring was common when this was recommended. High frequency and seriousness were associated with more prescribing-related actions. Conclusion Frequency and seriousness of the safety issue and the recommended action are likely to influence the impact of DHPCs. The timing of communication could be tailored depending on the content, where less urgent safety issues might be communicated periodically
Sex Differences in Adverse Drug Reactions of Metformin:A Longitudinal Survey Study
Introduction: In general, women more often experience metformin-associated adverse drug reactions (ADRs) than men. Objectives: We aimed to assess whether sex differences in reported ADRs for metformin are observed at different times after initiation, and to explore their concurrence with sex differences in the dose of metformin over time. This may guide future studies in assessing the involved mechanisms of sex differences in metformin-associated ADRs and may guide sex-specific management of ADRs in clinical practice. Methods: This study has a longitudinal design using data about patients initiating metformin collected by the Dutch National Pharmacovigilance Center Lareb through their Intensive Monitoring program. Patients were asked to complete a web-based questionnaire six times after initiation (i.e., at 2Â weeks, 6Â weeks and at 3, 6, 9, and 12Â months). The outcome variables were the proportion of patients reporting any ADR (primary) and the dose of metformin (secondary). Sex differences in the proportions of ADRs and in the dose were tested at each assessment using Pearson Chi-Squared tests and Wilcoxon rank-sum tests, respectively. Using Bonferroni adjustment for multiple testing, a p value < 0.01 was considered statistically significant. Results: The number of included patients was 1712 (40.9% women). Women reported an ADR more often than men, which was statistically significant at the assessment at 2Â weeks (34% vs 25%, p < 0.001), and 6Â weeks (37% vs 28%, p = 0.001) after initiation. In general, women were reported to be prescribed a lower dose than men, which became statistically significant at the 9-month assessment (p < 0.01). Conclusions: Sex differences in reported ADRs were seen in the first weeks after metformin initiation, whereas statistically significant differences in self-reported prescribed dosing were observed after several months. Patients, in particular women, might benefit from being prescribed lower metformin doses at treatment initiation
Handling of New Drug Safety Information in the Dutch Hospital Setting:A Mixed Methods Approach
INTRODUCTION: The implementation of new drug safety information and Direct Healthcare Professional Communications (DHPCs) in hospitals is important for patient safety. OBJECTIVES: The aim of this study was to gain insight into which procedures and practices are in place to handle new drug safety information and particularly DHPCs in the Dutch hospital setting. METHODS: We first conducted focus groups including medical specialists and hospital pharmacists, focusing on handling of drug safety information at the individual and organisational level. A survey was then developed and distributed among hospital pharmacists in all Dutch hospitals to quantify the existence of specific procedures and committees to handle drug safety information and DHPCs. RESULTS: Eleven specialists and 14 pharmacists from six hospitals participated in focus groups. Drug safety information was usually considered before drugs were included in formularies or treatment protocols. Furthermore, drug safety information was consulted in response to patients experiencing adverse events. DHPCs were mostly dealt with by individual professionals. DHPCs could lead to actions but this was very uncommon. Completed surveys were received from 40 (53%) of the hospitals. In 32 (80%), the hospital pharmacy had procedures to deal with new drug safety information, whereas in 11 (28%) a hospital-wide procedure was in place. Drug safety was considered in committees concerning drug formulary decisions (69%) and antibiotic policies (63%). DHPCs were assessed by a hospital pharmacist in 50% of the hospitals. CONCLUSIONS: Drug safety information was used for evaluation of new treatments and in response to adverse events. Assessment of whether a DHPC requires action was primarily an individual task
Prediction of plant species occurrence as affected by nitrogen deposition and climate change on a European scale
Plant species occurrence in Europe is affected by changes in nitrogen deposition and climate. Insight into potential future effects of those changes can be derived by a model approach based on field-based empirical evidence on a continental scale. In this paper, we present a newly developed empirical model PROPS, predicting the occurrence probabilities of plant species in response to a combination of climatic factors, nitrogen deposition and soil properties. Parameters included were temperature, precipitation, nitrogen deposition, soil pH and soil C/N ratio. The PROPS model was fitted to plant species occurrence data of about 800,000 European relevés with estimated values for pH and soil C/N ratio and interpolated climate and modelled N deposition data obtained from the Ensemble meteo data set and EMEP model results, respectively. The model was validated on an independent data set. The test of ten species against field data gave an average Pearson's r-value of 0.79.
PROPS was applied to a grassland and a heathland site to evaluate the effect of scenarios for nitrogen deposition and climate change on the Habitat Suitability Index (HSI), being the average of the relative probabilities, compared to the maximum probability, of all target species in a habitat. Results for the period 1930–2050 showed that an initial increase and later decrease in nitrogen deposition led to a pronounced decrease in HSI, and with dropping nitrogen deposition to an increase of the HSI. The effect of climate change appeared to be limited, resulting in a slight increase in HSI
Factors Influencing the Use of a Mobile App for Reporting Adverse Drug Reactions and Receiving Safety Information:A Qualitative Study
Introduction A mobile app may increase the reporting of adverse drug reactions (ADRs) and improve the communication of new drug safety information. Factors that influence the use of an app for such two-way risk communication need to be considered at the development stage. Objective Our aim was to reveal the factors that may influence healthcare professionals (HCPs) and patients to use an app for two-way risk communication. Methods Focus group discussions and face-to-face interviews were conducted in the Netherlands, Spain and the UK. Patients with type 2 diabetes mellitus, patients with a rare disease or their caregivers and adolescents with health conditions were eligible to participate. HCPs included pharmacists, paediatricians, general practitioners, internists, practice nurses and professionals caring for patients with a rare disease. Patients and HCPs were recruited through various channels. The recorded discussions and interviews were transcribed verbatim. The dataset was analysed using thematic analysis and arranged according to the Unified Theory of Acceptance and Use of Technology. Results Seven focus group discussions and 13 interviews were conducted. In total, 21 HCPs and 50 patients participated. Identified factors that may influence the use of the app were the type of feedback given on reported ADRs, how ADR reports are stored and the type of drug news. Also mentioned were other functions of the app, ease of use, type of language, the source of safety information provided through the app, security of the app, layout, the operating systems on which the app can be used and the costs. Conclusions Further research is needed to assess associations between user characteristics and the direction (positive or negative) of the factors potentially influencing app use
Simulation of critical loads for nitrogen for terrestrial plant communities in the Netherlands
An iterative search procedure was used to 'invert' the soil chemical model SMART2. This 'inverted' form of SMART2 was used to estimate atmospheric nitrogen deposition at the critical conditions for 139 terrestrial vegetation associations. The critical conditions are the lower end of the pH range, and the upper end of the nitrogen availability range for each association, estimated on the basis of Ellenberg values of vegetation relevees. The resulting critical load values were subjected to an uncertainty analysis. The estimation of nitrogen availability on the basis of Ellenberg's indicator for N has the largest contribution to the uncertainty. The critical load over all vegetation types and soil types is estimated to be 22 + 8 kg N ha-1.y-1. This is a rather 'hard' value, however critical loads per vegetation type are less 'hard', and it is not possible to determine critical load values per site. The uncertainties can only be reduced if more data become available on the abiotic response per species under field conditions. The critical loads found in this study were compared to the 'herijking' and 'SMB' critical loads and to empirically derived values. The 'SMB' critical loads appeared to be far lower than all other critical loads, which were in the same order of magnitud
- …