ArchiveSpark: Efficient Web Archive Access, Extraction and Derivation

Web archives are a valuable resource for researchers of various disciplines. However, to use them as a scholarly source, researchers require a tool that provides efficient access to Web archive data for extraction and derivation of smaller datasets. Besides efficient access we identify five other objectives based on practical researcher needs such as ease of use, extensibility and reusability. Towards these objectives we propose ArchiveSpark, a framework for efficient, distributed Web archive processing that builds a research corpus by working on existing and standardized data formats commonly held by Web archiving institutions. Performance optimizations in ArchiveSpark, facilitated by the use of a widely available metadata index, result in significant speed-ups of data processing. Our benchmarks show that ArchiveSpark is faster than alternative approaches without depending on any additional data stores while improving usability by seamlessly integrating queries and derivations with external tools.Comment: JCDL 2016, Newark, NJ, US

Analysing applicant's attraction with social networks on both sides of the table : those who recruit and those who are recruited have a compatible performance?

Applicant’s attraction in recruitment is perhaps one of the best known areas that integrate knowledge from different fields of research, such as the Hrm, Communication and Work and Organizational Psychology. Under this thematic, the social networks (SN) began to be understood as useful for recruitment purposes. The main objective of this research is to describe and understand the compatibility between the practices of recruiters regarding applicant’s attraction using SN and the expectations of the latter ones when looking for jobs via SN. This work has allowed us to generate a set of considerations regarding the theoretical, empirical and practical levels.info:eu-repo/semantics/publishedVersio

Clinical pharmacology of oral anticoagulants : pharmacoepidemiology, safety and pharmacoeconomics

Tese de doutoramento, Medicina (Farmacologia Clínica), Universidade de Lisboa, Faculdade de Medicina, 2017INTRODUCTION Oral anticoagulant drugs are essential in the treatment and prevention of thromboembolic events in certain prothrombotic conditions. Atrial fibrillation is the most prevalent arrhythmia, and is the main indication for chronic oral anticoagulation due to its thrombotic complications. Vitamin K antagonists (VKA) were until recently the only therapeutic options of this class in Portugal, namely in the form of warfarin and acenocoumarol. Despite proven efficacy, VKAs have a large pharmacodynamic variability owing to multiple potential interactions with food and other drugs. The development of the non-vitamin K antagonist oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban, and rivaroxaban) increased the therapeutic armamentarium for anticoagulation. NOACs act directly by blocking thrombin or factor Xa, and exhibit an antithrombotic effect at least as effective as VKAs. Since the myriad of interactions found with VKAs are absent in NOACs, the anticoagulant effect is predictable, and does not require serial evaluations of hemostasis, making NOACs more convenient for patients and clinicians. Thus, it is reasonable to expect that NOACs may be prescribed often than VKAs. However, the approval of NOACs was based on phase III randomized controlled trials (RCTs), which are seldom planned to evaluate the safety of interventions. Additionally, NOACs are costlier than VKAs, raising the question of whether these new anticoagulants promote health gains at a sustainable cost to the Portuguese society. Therefore, it is important to better characterize the oral anticoagulants with a focus on NOACs in the population-level clinical pharmacology, namely pharmacoepidemiology, safety aspects of the oral anticoagulants (comparative safety and pharmacovigilance) and pharmacoeconomics. OBJECTIVES The aim of this dissertation was to improve the knowledge related to the oral anticoagulants in the four main fields population-level clinical pharmacology: pharmacoepidemiology, comparative effectiveness/safety, pharmacovigilance, and pharmacoeconomics. Specific objectives: 1) Pharmacoepidemiology: To assess the state of oral anticoagulation in Portugal, in terms of proportion of non-anticoagulated patients, the quality of anticoagulation, and evolution of the prescription pattern since the licensing of NOACs. 2) Comparative effectiveness/safety research: To evaluate the safety of NOACs, based on clinical trials’ data, in terms of bleeding and non-bleeding adverse events, as well as the overall tolerability and acceptability of the drugs. 3) Pharmacovigilance: To identify adverse events related to oral anticoagulants most frequently reported to Pharmacovigilance Units in Portugal. 4) Pharmacoeconomics: To assess the cost and burden of AF in Portugal, and the relative cost-effectiveness of oral anticoagulants in Portugal. METHODS To achieve the objectives, the following research projects were conducted: 1) Pharmacoepidemiology: A systematic review and meta-analysis of all published studies in Portugal assessing the prescription/use of oral anticoagulant therapy in patients with AF; A retrospective observational study of a cohort of patients treated with VKAs for assessment of anticoagulation control quality through the Rosendaal Time in Therapeutic Range (TTR); A retrospective observational study of national outpatient prescribing oral anticoagulants, with characterization of the number of boxes sold and Defined Daily Dose (DDD, a standardized measure of the World Health Organization) prescribed for each group of drugs. 2) Comparative effectiveness/safety research: Systematic review and meta-analyses based on aggregated data of phase III RCTs of NOACs compared to VKAs, for bleeding events, overall tolerability, and acceptability; and NOACs compared to all available comparators for non-bleeding adverse events. The data were pooled using a randomeffects model, and expressed as relative risk (RR) with a confidence interval of 95% (95%CI). 3) Pharmacovigilance: A retrospective observational study of spontaneous reports related to oral anticoagulants, received by the National Pharmacovigilance System in Portugal. 4) Pharmacoeconomics: A study concerning the cost of illness and burden of AF, and a cost-effectiveness study of oral anticoagulants in Portugal for AF were performed. To the burden of disease assessment, disability-adjusted life years (DALYs) related to the AF were estimated, as well as both the direct (inpatient and outpatient) and indirect (lost productivity) associated costs. To evaluate the cost-effectiveness, a Markov model was used, with characteristics adjusted to Portugal. The relative costs and health gains associated with NOACs were estimated and weighed through the Incremental Cost Effectiveness Ratio (ICER), which evaluates the cost of each Quality-Adjusted Life Years (QALY) gained for a given intervention in relation to the control intervention (VKAs and all NOACs). RESULTS 1) About 60% of patients with AF in Portugal were not treated with oral anticoagulants, and oral anticoagulation with VKAs had a suboptimal control with a mean TTR of 61%, according with the single-centre retrospective study. Since the introduction of NOACs in the Portuguese market, the number of pack and DDD of oral anticoagulants prescribed increased significantly, this rise being due to NOACs. Currently the NOACs as pharmacological group have most of the market share of oral anticoagulants. 2) In the pooled safety data from phase III RCTs, NOACs were associated with a decreased risk of major bleeding (RR 0.72; 95% CI: 0.61 to 0.84; 12 RCTs), fatal bleeding (RR 0.52; 95% CI: 0.65 to 0.41; 12 RCTs) and ICH (RR 0.43; 95% CI: 12.36 to 12.51; 11 RCTs) compared to the VKA. Regarding major gastrointestinal, intraocular, and pericardial bleeding, there was no increase in the risk of these events. The NOACs are not associated with liver injury (RR 0.93; 95% CI: 0.75 to 1.15; 26 RCTs) or severe renal impairment (RR 0.93; 95% CI: 0.82 to 1.05; 7 RCTs). Similarly, there was no increased risk of infections or insomnia. The overall risk of serious adverse events was significantly decreased by NOACs compared to VKAs (RR 0.96; 95% CI: 0.94 to 0.98; 5 RCTs). The results for acceptability (drug discontinuation) were heterogeneous. However, for most NOACs the risk of treatment discontinuation due to drug-related or patient-related reasons were not increased compared to the VKAs in AF patients. 3) The Pharmacovigilance study data showed that most the reported adverse events were related to NOACs (78%). About 25% of these events were related to bleeding and 10% related thromboembolic events. The annual number of notifications has been increasing, but when adjusted to the degree of drugs exposure, the peak incidence was in 2012, with a subsequent decrease. 4) AF has an important burden in Portugal contributing to the yearly loss of 23084 DALYs and expenses of 141 million € (57% in direct costs and 43% in indirect costs). NOACs were shown to be cost-effective compared with VKAs for the prevention of thromboembolic events in non-valvular atrial fibrillation. In the presented model, apixaban was shown to be cost-effective compared to warfarin (ICER €5529/ QALY) and dabigatran (ICER €9163/QALY), and dominant compared to rivaroxaban. CONCLUSIONS The proportion of patients receiving oral anticoagulant treatment is increasing in Portugal, mostly due to NOACs. These drugs have an acceptable safety profile, with an improvement of the risk of fatal and serious bleeding events, particularly intracranial hemorrhage, without substantial increase in other non-bleeding events, including hepatic, renal, or infectious. The risk of adverse events is generally lower, and most NOACs do not show an increased risk of discontinuation. Although most adverse events reported to the National Pharmacovigilance system are associated with the NOACs, the number of events since the increase in drug exposure has declined. Atrial fibrillation, the main indication for oral anticoagulation, has an important burden, with costs related to the disease that account for about 0.1% of gross domestic product of Portugal. The NOACs use for stroke prevention in AF is cost-effective compared with VKAs