1,720,999 research outputs found
Prognosis and cost-effectiveness of IVF in poor responders according to the Bologna criteria
No full textPoor ovarian response (POR) to controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF) is one of the most challenging issue in the field of reproductive medicine. However, even if improving IVF outcome in poor responders (PORs) represents a main priority, the lack of a unique definition of POR has hampered research in this area. In order to overcome this impediment, an ESHRE Campus Workshop was organized in Bologna in 2010 and reached a consensus on the criteria for the diagnosis of POR ('Bologna criteria'). In this review we aimed to estimate the prognostic potential of the ESHRE definition, to elucidate its possible weaknesses and to analyze the economic aspects of IVF in a population of poor responders (PORs). Available evidence confirmed that the Bologna criteria are able to select a population with a poor IVF prognosis thus supporting their validity. Nonetheless, different aspects of the definition have been criticized. The main points of debate concern the homogeneity of the population identified, the cut-off values chosen for the ovarian reserve tests (ORTs) and the risks factors other than age associated with POR. Data concerning the economic profile of IVF in PORs are scanty. The only published study on the argument showed that IVF in these cases is not cost-effective. However, considering the potential substantial impact of cost-effectiveness analyses on public health policies, there is the need for further and independent validations
Reply: The impact of thyroid autoimmunity on IVF/ICSI outcome: re-evaluation of the findings
No full textThe impact of thyroid autoimmunity on IVF/ICSI outcome : a systematic review and meta-analysis
No full textBACKGROUND: Thyroid autoimmunity (TAI) is the most frequent autoimmune condition and the first cause of thyroid dysfunction
among women of reproductive age. Notably, it has been associated with adverse obstetric outcomes during all trimesters of pregnancy.
Furthermore, since most studies show an increased prevalence of TAI among women attending infertility clinics, a detrimental impact of
this condition on natural fertility and on the rate of success of assisted reproductive techniques has been suggested. However, to date, the results have been inconsistent.
OBJECTIVE AND RATIONALE: The objective of this study was to define the relation between TAI per se and the outcome of in vitro
fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles.
SEARCH METHODS: A systematic literature review and meta-analysis were conducted. A Medline search was performed to identify all
the comparative studies published from January 1990 to November 2015 in the English language literature on IVF/ICSI outcome in women with and without TAI, using combinations of the medical subject heading terms ‘thyroid autoimmunity’, ‘thyroid autoantibodies’, ‘IVF’, ‘ICSI’, ‘pregnancy’, ‘miscarriage’ and ‘delivery’. The primary outcome was live birth rate (LBR). Our secondary outcomes were number of oocytes retrieved (NOR), fertilisation rate (FR), implantation rate (IR), clinical pregnancy rate (CPR) and miscarriage rate (MR). We also extracted data on mean age and basal serum concentrations of thyroid stimulating hormone (TSH) and performed a meta-regression analysis to assess the effect of these two covariates on CPR and MR.
OUTCOMES: We selected 12 studies for the meta-analysis. Six of the included studies were prospective cohort studies, and six
were retrospective cohort studies. Compared with women with negative TAI, women with positive TAI had a lower LBR (odds ratio
(OR) 0.73; 95% confidence interval (CI) [0.54–0.99]; P = 0.04; 9 studies; 4396 women; I2 = 41%), a higher MR (OR 1.44; 95%
CI [1.06–1.95]; P = 0.02; 12 studies; 4876 women; I2 = 35%), a similar CPR (OR 0.90; 95% CI [0.77–1.06]; P = 0.22; 12 studies;
4876 women; I2 = 7%), a similar number of oocytes (standardized mean difference [SMD] 0.10; 95% CI [−0.09 to 0.29]; P = 0.28;
5 studies; 1506 women; I2 = 47%), a similar FR (OR 1.11; 95% CI [0.97–1.27]; P = 0.13; 3 studies; 1082 women; I2 = 0%) and a similar
IR (OR 0.98; 95% CI [0.73–1.32]; P = 0.91; 2 studies; 918 women; I2 = 0%). Both mean age (SMD 0.96; 95% CI [0.66–1.27];
P < 0.00001; 9 studies; 3256 women; I2 = 85%) and serum TSH (SMD 0.24; 95% CI [0.15–0.34]; P < 0.00001; 6 studies; 2098
women; I2 = 59%) were higher in women with TAI. However, neither of these two covariates were significantly associated with CPR
or MR.
WIDER IMPLICATIONS: TAI does not impact on IVF/ICSI outcome in terms of NOR and likelihood of fertilisation, implantation and
clinical pregnancy. On the contrary, the presence of thyroid autoantibodies may have a detrimental effect on the course of a pregnancy,
determining an increased risk of miscarriage and a decreased chance of live birth. However, given the possible modifying effects of age and serum TSH, further evidence is warranted prior to drawing inferences on causality
Forever Young:Testosterone replacement therapy: a blockbuster drug despite flabby evidence and broken promises
Full text linkIn the last decade, testosterone replacement therapy (TRT) has been increasingly prescribed to treat a controversial condition known as 'late-onset hypogonadism (LOH)'. This syndrome is diagnosed in men who, for no discernible reason other than older age, obesity or ill health have serum testosterone concentrations below the normal range for healthy young men and report one or more of the following symptoms: muscle weakness or wasting, mood, behaviour and cognition-related symptoms and sexual function or libido impairment. However, recent evidence has demonstrated that testosterone drugs do not substantially ameliorate these symptoms and, more worryingly, that their long-term use may be associated with severe adverse effects (i.e. increased risk of prostate cancer, stroke and myocardial infarction, worsening of benign prostatic hyperplasia symptoms and testicular atrophy). Nonetheless, testosterone drugs have exhibited extraordinary commercial success and their pharmaceutical sales are steadily rising. Behind this apparently unjustifiable trend there are deliberate, well designed direct and indirect pharmaceutical marketing initiatives that exploit the conviction rooted in contemporary society that testosterone can reverse the effects of ageing and ensure social accomplishment. Commercial mechanisms have laid the foundation for disease mongering of LOH and also have resulted a considerable expansion of the indications for treatment. This promotion model deserves particular attention since it is applicable to any drug with a purportedly favourable risk-benefit ratio not supported by evidence
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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