Number needed to treat based on real-world evidence for non-vitamin K antagonist oral anticoagulants versus vitamin K antagonist oral anticoagulants in stroke prevention in patients with non-valvular atrial fibrillation

Aims: Non-vitamin K antagonist oral anticoagulants (NOACs) and vitamin K antagonists (VKAs) are used to prevent stroke in patients with atrial fibrillation (AF). This paper aimed to evaluate the clinical efficacy and safety of NOACs when compared to VKAs by calculating the number needed to treat (NNT) at 2 years using incidence rates and hazard ratios (HRs) derived from a meta-analysis of studies conducted in real-world settings.

Materials and methods: HRs were sourced from a published systematic literature review and a meta-analysis of real-world evidence on the use of NOACs vs VKAs. Rivaroxaban, dabigatran, and apixaban vs VKAs were investigated. The efficacy outcomes included: a composite of ischaemic stroke and systemic embolism (IS/SE), ischaemic stroke (IS), and all-cause mortality. The safety analysis assessed major bleeding and intracranial haemorrhage (ICH).

Results: Superiority of NOACs vs VKAs was observed in 10/15 comparisons. Treating patients with rivaroxaban and dabigatran was associated with a reduced risk of IS and all-cause mortality compared to VKAs, with one death prevented every 22 and 32 patients, respectively, and one IS prevented every 206 and 166 patients, respectively. Rivaroxaban was significantly associated with a reduced risk of IS/SE compared to VKA (NNT: 107). No significant differences were observed between apixaban and VKAs. Dabigatran and apixaban were associated with a reduced risk of major bleeding compared to VKA (NNT: 59 and 38, respectively). No significant difference was observed between rivaroxaban and VKAs regarding major bleeding. Rivaroxaban, dabigatran, and apixaban were significantly associated with a reduced risk of ICH (NNT: 205, 115, and 108, respectively).

Limitations: Heterogeneity in definitions of major bleeding across studies.

Conclusions: The NNT calculation, when approached and interpreted properly, is a practical measure of the effectiveness of a treatment. The calculation based on HRs showed that NOACs are safe and effective alternatives to VKAs in real life.     

Soil and cropping system research in semi-arid West Africa as related to the potential for conservation agriculture

Semi-arid West Africa faces challenges to increase sorghum and pearl millet production to meet food needs for a growing human population while increasing soil carbon (C), nutrient levels, and water holding capacity that are documented benefits of conservation agriculture. This review focuses on the wealth of research on cropping systems, tillage, crop residue, nutrient, and weed management as related to conservation agriculture. It also identifies needs for multidisciplinary, integrative research to assist the transition from current production systems to conservation agriculture. Crop residue use as livestock feed, or fuel are major constraints to adoption of conservation agriculture, which could be reduced by wood production in agroforestry systems, alternate energy sources, and increased forage supply. Crop residue and grain yields are related, thus improved crop, soil, water, nutrient, and weed management to increase grain yield would also increase the supply of crop residue with potential for ‘left over’ crop residue being available for soil mulching. Incorporating indigenous shrubs and/or cover crops could also increase crop residue supply. Species diversity can be increased through crop rotation, agroforestry, cover crops, and intercrops. Higher grain and stover yields and increased profit potential for resource-poor farmers in West Africa will be required before wide-scale adoption of conservation agriculture will be possible.     

The efficiencies of Chinese coal-fired power plants: a stochastic-frontier approach

We apply the stochastic frontier of translog production function to estimate the efficiencies of Chinese coal-fired power plants, using a survey sample of 300 power plants over 5 years from 2004 to 2008 for estimation. By taking into account, the ages of generators and a technological factor reflected by a dummy for supercritical generators, we identified the improvement of efficiencies in the Chinese power industry over the period, and the coal-fired power plants that still run inefficiently by approximate 9% on average when compared with the best practice of cost efficiency in the power industry.     

A paradigm shift in African agricultural research for development: the role of innovation platforms

To demonstrate the development impact of their outputs, agricultural research and development (R&D) organizations used to focus on the efficiency and effectiveness of technologies. In recent years, innovation systems thinking has started to address institutional and organizational barriers to technological change in African agriculture. The main approach used has been the multi-stakeholder innovation platform (IP). This paper analyses the requirements for improving the competence and skills of IPs actors in agricultural value chains, food systems, and natural resource management. As case studies, it uses IPs in the maize and cassava value chains that were initiated in the dissemination of new agricultural technologies in Africa (DONATA), in both West and Central Africa, and made reference to the rice IPs facilitated by AfricaRice. Yields and incomes in maize and cassava IPs significantly increased and inter-actor relationships and behavioural change among the diverse social and economic operators were enhanced. This achievement built on three capacity development interventions: (i) learning workshops that sensitized and informed technocrats and policy-makers and nurtured their involvement and ownership, (ii) competence and skill training of IP facilitators and practitioners, and (iii) coaching and mentoring of these facilitators and practitioners. To better facilitate IPs, facilitators and practitioners need to learn to observe, recreate, test, and perfect the IP process and value chain approach. Practicable tools that can be visualized and put into practice by the IP actors are essential. The DONATA on which the paper is based has been invaluable in terms of experiential learning.     

Cost-effectiveness analyses using real-world data: an overview of the literature

Abstract

Objectives: Real-world evidence (RWE) may provide good estimates of absolute event probabilities and costs in patients in actual clinical practice, but their use in decision-analytic models poses many challenges. A literature review based on a systematic search was conducted to summarize the limitations of using RWE in decision-analytic modeling reported in the literature, but also to identify existing recommendations about real-world modeling.

Methods: A literature search was performed on Medline and Embase databases, as well as relevant websites. No restrictions in language or geographical scope were imposed.

Results: A total of 14 references were included. RWE is recognized as a valuable source of data for market access and reimbursement, and as a complement to clinical trial evidence for treatment pathways, resource use, long-term natural history, and effectiveness. The main limitations identified in the literature were: confounding bias, missing data, lack of accurate data related to drug exposure and outcomes, errors during the record-keeping process, protection of private data, and insufficient numbers of patients. Although most submission guidelines recognized the potential biases associated with RWE, guidance on the appropriate methods to deal with these biases, and approaches to review different relevant evidence to inform model development, were scarce. Several initiatives have attempted to provide guidance on the use of RWE in decision-modeling.

Conclusions: RWE is likely to be particularly valuable for informing healthcare policy-makers when formulating appropriate treatment pathways, encouraging the optimal allocation of scarce resources, and improving aggregate patient outcomes. However, little guidance is available on the relative merits of using efficacy and/or effectiveness evidence in Health Technology Appraisal submissions. Further research is needed to better understand these methods and their potential applications in a broader range of scenarios and simulation studies, and their impact on economic modeling.     

Beyond Paternalism: Cross-cultural Perspectives on the Functioning of a Mexican Production Plant

Expatriate managers of international businesses in emerging countries often struggle to mobilize their workforces. They sometimes perceive profound cultural differences as a barrier to the progress of their organizations. Some international businesses may adopt a paternalistic attitude toward their employees; but this questionable strategy brings mixed results. Are there ways out of paternalism for international businesses in emerging areas? This paper examines the diverging views held by foreign managers and local personnel of a foreign-owned production plant in Mexico, which managed to mobilize its workforce by building a strong sense of community, allowing a certain form of collective control to replace the paternalistic model, with its bonds of personal allegiance. Contrasting perspectives between Mexican and foreign employees show that intercultural misunderstandings, rather than the peculiarities of the local culture, are the greatest challenge to cooperation.     

Creative destruction with on-the-job search

This paper studies the consequences of creative destruction on unemployment in a frictional labor market with on-the-job search. For a benchmark calibration, a 1% increase in growth raises the unemployment rate by 1.72 percentage points in the economy without on-the-job search and by only 0.07 percentage points with on-the-job search. Rather than contributing to unemployment through more frequent job separations, in the presence of on-the-job search, creative destruction induces a direct reallocation of workers from low to high productivity jobs.     

Use of real-world evidence in meta-analyses and cost-effectiveness models

Abstract

Real-world evidence (RWE) provides external validity, supplementing and enhancing the randomized controlled trial data with valuable information on patient behaviors and outcomes, turning efficacy and safety results into real-world effectiveness and risks, but the use of RWE is associated with challenges. The objectives of this communication were to (1) summarize all guidance on how to conduct an RWE meta-analysis (MA) and how to develop an RWE cost-effectiveness model, (2) to describe our experience, challenges faced and solutions identified, (3) to provide recommendations on how to conduct such analyses. No formal guidelines on how to conduct an RWE MA or to develop an RWE cost-effectiveness model were identified. Using the context of non-vitamin K antagonist oral anticoagulants in stroke prevention in atrial fibrillation, we conducted an RWE MA, after having identified sources of uncertainty. We then implemented the results in an RWE cost-effectiveness model, defined as a model where all inputs come from RWE, including all parameters related to treatment effect. Based on challenges faced, our first recommendation relates to the necessity of conducting sensitivity analyses, either based on clinical or methodological considerations. Our second recommendation is the need for extensive collaboration with a wide range of experts, during the development of the analyses protocols, the implementation of the analyses and the interpretation of the results. RWE may address a number of gaps related to the treatment effect, and RWE economic evaluations for the treatment effect can provide extremely valuable insights into real-world economic value of interventions. As the increased recognition of the value of RWE could influence health technology assessment decision, and current practices, this communication supports the urgent need of more formal guidelines.     

Farm resources,transaction costs and forward integration in agriculture: Evidence from French wine producers

This research aims to understand why French wine producers venture into direct sale to customers instead of selling bulk wine to wine companies. The empirical tests on the French Farm Census confirm the value of both Resource-Based Perspective and Transaction Cost Economics in understanding organizational choices in agriculture and food markets. Because asset specificity in wine trade is low on average, large wine producers have an advantage over smaller ones and so are more likely to venture into direct sale of generic wines. By contrast smaller wine producers are more likely to rely on the bulk wine market, which is less risky for them. In addition our model helps us to understand the effect of the State-sponsored certification of grape and wine quality, the Protected Designation of Origin system. All other things being equal, producers with vineyards of high reputation (PDO) are also more likely to bottle and sell their wines; we guess this is because they wish to capture the value of the PDO reputation, the collective brand name capital owned by the farmers. Finally, saving on transaction cost is only one side of the coin: the most educated wine producers can profitably reinvest their knowledge and capabilities into new activities. These choices have important consequence on the French Wine Supply Chain governance.     

A counterfactual experiment about the eradication of cattle diseases on beef trade

In response to disease outbreak alerts in exporting countries, importing countries usually impose trade bans that vary in terms of product coverage and in terms of duration. We rely on a unique balanced panel dataset that covers four-digit disaggregated beef products over the 1996–2013 period, to estimate the effect of a hypothetical removal of animal diseases outbreaks on trade flows. More specifically, we investigate how bovine spongiform encephalopathy (BSE) and the foot and mouth diseases (FMDs) affect beef trade flows. We use a sectoral structural gravity approach to measure direct, conditional, and full effects, allowing inward and outward multilateral resistance indices, expenditures, and factory-gate prices to adjust to the eradication of animal diseases. The indirect channels through which BSE and FMD impact trade are important. Our counterfactual experiment suggests that Canada would secure substantial gains from BSE and FMD eradication.