Doppler ultrasound in the measurement of pulse wave velocity: agreement with the Complior method

Aortic stiffness is an independent predictor factor for cardiovascular risk. Different methods for determining pulse wave velocity (PWV) are used, among which the most common are mechanical methods such as SphygmoCor or Complior, which require specific devices and are limited by technical difficulty in obtaining measurements. Doppler guided by 2D ultrasound is a good alternative to these methods. We studied 40 patients (29 male, aged 21 to 82 years) comparing the Complior method with Doppler. Agreement of both devices was high (R = 0.91, 0.84-0.95, 95% CI). The reproducibility analysis revealed no intra-nor interobserver differences. Based on these results, we conclude that Doppler ultrasound is a reliable and reproducible alternative to other established methods for themeasurement of aortic PWV

Beyond GDP: Methodological and measurement issues in redefining “wealth”

In the last decades; a growing stock of literature has been devoted to the criticism of GDP as an indicator of societal wealth. A relevant question is: what are the perspectives to build, on the existing knowledge and consensus, alternative measures of prosperity? A starting point may be to connect well-being research agenda with the sustainability one. However, there is no doubt that there is a lot of complexity and fuzziness inherent in multidimensional concepts such as sustainability and well-being. This article analyses the theoretical foundations and the empirical validity of some multidimensional technical tools that can be used for well-being evaluation and assessment. Of course one should not forget that policy conclusions derived through any mathematical model depend also on the conceptual framework used, i.e. which representation of reality (and thus which societal values and interests) has been considered.

The COSMIN checklist for evaluating the methodological quality of studies on measurement properties: a clarification of its content

Background: The COSMIN checklist (COnsensus-based Standards for the selection of health status Measurement INstruments) was developed in an international Delphi study to evaluate the methodological quality of studies on measurement properties of health-related patient reported outcomes (HR-PROs). In this paper, we explain our choices for the design requirements and preferred statistical methods for which no evidence is available in the literature or on which the Delphi panel members had substantial discussion. Methods: The issues described in this paper are a reflection of the Delphi process in which 43 panel members participated. Results: The topics discussed are internal consistency (relevance for reflective and formative models, and distinction with unidimensionality), content validity (judging relevance and comprehensiveness), hypotheses testing as an aspect of construct validity (specificity of hypotheses), criterion validity (relevance for PROs), and responsiveness (concept and relation to validity, and (in) appropriate measures).Conclusions: We expect that this paper will contribute to a better understanding of the rationale behind the items, thereby enhancing the acceptance and use of the COSMIN checklist.

Inter-rater agreement and reliability of the COSMIN (COnsensus-based Standards for the selection of health status Measurement Instruments) Checklist

Background: The COSMIN checklist is a tool for evaluating the methodological quality of studies on measurement properties of health-related patient-reported outcomes. The aim of this study is to determine the inter-rater agreement and reliability of each item score of the COSMIN checklist (n = 114). Methods: 75 articles evaluating measurement properties were randomly selected from the bibliographic database compiled by the Patient-Reported Outcome Measurement Group, Oxford, UK. Raters were asked to assess the methodological quality of three articles, using the COSMIN checklist. In a one-way design, percentage agreement and intraclass kappa coefficients or quadratic-weighted kappa coefficients were calculated for each item. Results: 88 raters participated. Of the 75 selected articles, 26 articles were rated by four to six participants, and 49 by two or three participants. Overall, percentage agreement was appropriate (68% was above 80% agreement), and the kappa coefficients for the COSMIN items were low (61% was below 0.40, 6% was above 0.75). Reasons for low inter-rater agreement were need for subjective judgement, and accustom to different standards, terminology and definitions.Conclusions: Results indicated that raters often choose the same response option, but that it is difficult on item level to distinguish between articles. When using the COSMIN checklist in a systematic review, we recommend getting some training and experience, completing it by two independent raters, and reaching consensus on one final rating. Instructions for using the checklist are improved.

Protocol of the COSMIN study: consensus-based standards for the selection of health measurement instruments

Background: Choosing an adequate measurement instrument depends on the proposed use of the instrument, the concept to be measured, the measurement properties (e.g. internal consistency, reproducibility, content and construct validity, responsiveness, and interpretability), the requirements, the burden for subjects, and costs of the available instruments. As far as measurement properties are concerned, there are no sufficiently specific standards for the evaluation of measurement properties of instruments to measure health status, and also no explicit criteria for what constitutes good measurement properties. In this paper we describe the protocol for the COSMIN study, the objective of which is to develop a checklist that contains COnsensus-based Standards for the selection of health Measurement INstruments, including explicit criteria for satisfying these standards. We will focus on evaluative health related patient-reported outcomes (HR-PROs), i.e. patient-reported health measurement instruments used in a longitudinal design as an outcome measure, excluding health care related PROs, such as satisfaction with care or adherence. The COSMIN standards will be made available in the form of an easily applicable checklist.Method: An international Delphi study will be performed to reach consensus on which and how measurement properties should be assessed, and on criteria for good measurement properties. Two sources of input will be used for the Delphi study: (1) a systematic review of properties, standards and criteria of measurement properties found in systematic reviews of measurement instruments, and (2) an additional literature search of methodological articles presenting a comprehensive checklist of standards and criteria. The Delphi study will consist of four (written) Delphi rounds, with approximately 30 expert panel members with different backgrounds in clinical medicine, biostatistics, psychology, and epidemiology. The final checklist will subsequently be field-tested by assessing the inter-rater reproducibility of the checklist.Discussion: Since the study will mainly be anonymous, problems that are commonly encountered in face-to-face group meetings, such as the dominance of certain persons in the communication process, will be avoided. By performing a Delphi study and involving many experts, the likelihood that the checklist will have sufficient credibility to be accepted and implemented will increase.

Traducción comentada de “Genetically Modified Organisms (GMOs): Transgenic Crops and Recombinant DNA Technology”

The purpose of this paper is to provide a translation into Spanish of a review articleabout genetically modified organisms (GMOs) entitled “Genetically ModifiedOrganisms (GMOs): Transgenic Crops and Recombinant DNA Technology” publishedby the well-known scientific journal Nature. In a world where English has become thelingua franca when it comes to transferring scientific knowledge and information, itmust be taken into account that not everyone—from scientist to the general public—hasa good enough command of English so that they can feel comfortable enough reading inthis language. Translators are consequently needed resulting from a great demand oftranslation activity into, for example, Spanish. This is the reason why the proposedSpanish translation is followed by a detailed analysis emphasizing the difficulties andproblems that characterize scientific—and also general—translation (i.e. terminology,syntax, semantics, pragmatics, and ideology), for which different approaches as how tosolve them are provided. On the basis of the analysis, it can be concluded thatexperience will be of much help to scientific translators, given that specificterminological knowledge and style requirements must always be born in mind whentranslating in this field. Moreover, this paper is intended to serve as a guide forTranslation students specializing in the field of science and the expectation is to helpthem make the right decisions when it comes to translating. However, it is clear that itcan only be thought of as an introduction that should be completed with further researchand documentation tasks in order to offer a complete reference tool: the ultimatehandbook of scientific translation.

The Impact of Trade on Technology and Skill Upgrading Evidence from Argentina

In the last 20 years, wage inequality has increased in many developing countries. Most research on this topic focuses on two alternative causes: trade or skill-biased technical change. Several empirical studies in both developed and developing countries document increases in skill intensity within all sectors, favoring the technological change explanation over trade. Instead, I present and test a model where bilateral trade liberalization increases exporting revenues inducing more firms to enter the export market and to adopt skilled-biased new technologies. I find that the increase in the relative demand of skilled labor does not come from labor reallocation across sectors or firms but from skill upgrading within firms. Firms that upgrade technology faster also upgrade skill faster. Finally, firms entering the export market after liberalization become more skill and technology-intensive than non exporters.

Measurement with Some Theory: a New Approach to Evaluate Business Cycle Models

We propose a method to evaluate cyclical models which does not require knowledge of the DGP and the exact empirical specification of the aggregate decision rules. We derive robust restrictions in a class of models; use some to identify structural shocks and others to evaluate the model or contrast sub-models. The approach has good size and excellent power properties, even in small samples. We show how to examine the validity of a class of models, sort out the relevance of certain frictions, evaluate the importance of an added feature, and indirectly estimate structural parameters.

Productivity Growth during the English Industrial Revolution: A Dual Approach

This paper presents new estimates of total factor productivity growth in Britain for the period 1770-1860. We use a dual technique recently popularized by Hsieh (1999), and argue that the estimates we derive from factor prices are of similar quality to quantity-based calculations. Our results provide further evidence, derived from this independent set of sources, that productivity growth during the British Industrial Revolution was relatively slow. During the years 1770-1800, TFP growth was close to zero, according to our estimates. The period 1800-1830 experienced an acceleration of productivity growth. The Crafts-Harley view of the Industrial Revolution is thus reinforced. We also consider alternative explanations of slow productivity growth, and reject the interpretation that focuses on the introduction of steam as a general purpose technology.

The Labor Market Effects of Technology Shocks

We analyze the labor market effects of neutral and investment-specific technology shocks along the intensive margin (hours worked) and the extensive margin (unemployment). We characterize the dynamic response of unemployment in terms of the job separation and the job finding rate. Labor market adjustments occur along the extensive margin in response to neutral shocks, along the intensive margin in response to investment specific shocks. The job separation rate accounts for a major portion of the impact response of unemployment. Neutral shocks prompt a contemporaneous increase in unemployment because of a sharp rise in the separation rate. This is prolonged by a persistent fall in the job finding rate. Investment specific shocks rise employment and hours worked. Neutral shocks explain a substantial portion of the volatility of unemployment and output; investment specific shocks mainly explain hours worked volatility. This suggests that neutral progress is consistent with Schumpeterian creative destruction, while investment-specific progress operates as in a neoclassical growth model.

Resolving inconsistencies in utility measurement under risk: Tests of generalizations of expected utility

This paper explores biases in the elicitation of utilities under risk and the contribution that generalizations of expected utility can make to the resolution of these biases. We used five methods to measure utilities under risk and found clear violations of expected utility. Of the theories studies, prospect theory was most consistent with our data. The main improvement of prospect theory over expected utility was in comparisons between a riskless and a risky prospect(riskless-risk methods). We observed no improvement over expected utility in comparisons between two risky prospects (risk-risk methods). An explanation why we found no improvement of prospect theory over expected utility in risk-risk methods may be that there was less overweighting of small probabilities in our study than has commonly been observed.

Globalization, technology and inequality

What are the effects of international integration on inequality, both between and within countries? The growing evidence that technology is the main determinant of wage and income differences may seem to imply that the forces of globalization only play a secondary role. Such a conclusion is however premature, in that it neglects the effect of international integration on technology itself. This opuscle summarizes recent and ongoing research studying how two important aspects of globalization, trade in goods and offshoring of production, shape the distribution of income when technological progress is endogenous. It discusses the theoretical foundations and the empirical support for various mechanisms through which international integration may change the incentive to develop and adopt new technologies and how this affects wages and the return to skill around the world.

Business cycle measurement with some theory

A method to evaluate cyclical models not requiring knowledge of the DGP and the exact specificationof the aggregate decision rules is proposed. We derive robust restrictions in a class of models; use someto identify structural shocks in the data and others to evaluate the class or contrast sub-models. Theapproach has good properties, even in small samples, and when the class of models is misspecified. Themethod is used to sort out the relevance of a certain friction (the presence of rule-of-thumb consumers)in a standard class of models.

The ins and outs of unemployment: An analysis conditional on technology shocks

We analyze how unemployment, job finding and job separation rates reactto neutral and investment-specific technology shocks. Neutral shocks increaseunemployment and explain a substantial portion of it volatility; investment-specificshocks expand employment and hours worked and contribute to hoursworked volatility. Movements in the job separation rates are responsible for theimpact response of unemployment while job finding rates for movements alongits adjustment path. The evidence warns against using models with exogenousseparation rates and challenges the conventional way of modelling technologyshocks in search and sticky price models.