Uses and misuses of the STROBE statement: bibliographic study

Objectives Appropriate reporting is central to the application of findings from research to clinical practice. The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations consist of a checklist of 22 items that provide guidance on the reporting of cohort, case-control and cross-sectional studies, in order to facilitate critical appraisal and interpretation of results. STROBE was published in October 2007 in several journals including The Lancet, BMJ, Annals of Internal Medicine and PLoS Medicine. Within the framework of the revision of the STROBE recommendations, the authors examined the context and circumstances in which the STROBE statement was used in the past. Design The authors searched the Web of Science database in August 2010 for articles which cited STROBE and examined a random sample of 100 articles using a standardised, piloted data extraction form. The use of STROBE in observational studies and systematic reviews (including meta-analyses) was classified as appropriate or inappropriate. The use of STROBE to guide the reporting of observational studies was considered appropriate. Inappropriate uses included the use of STROBE as a tool to assess the methodological quality of studies or as a guideline on how to design and conduct studies. Results The authors identified 640 articles that cited STROBE. In the random sample of 100 articles, about half were observational studies (32%) or systematic reviews (19%). Comments, editorials and letters accounted for 15%, methodological articles for 8%, and recommendations and narrative reviews for 26% of articles. Of the 32 observational studies, 26 (81%) made appropriate use of STROBE, and three uses (10%) were considered inappropriate. Among 19 systematic reviews, 10 (53%) used STROBE inappropriately as a tool to assess study quality. Conclusions The STROBE reporting recommendations are frequently used inappropriately in systematic reviews and meta-analyses as an instrument to assess the methodological quality of observational studies.

Antimicrobial use in Swiss dairy farms: quantification and evaluation of data quality

Data on antimicrobial use play a key role in the development of policies for the containment of antimicrobial resistance. On-farm data could provide a detailed overview of the antimicrobial use, but technical and methodological aspects of data collection and interpretation, as well as data quality need to be further assessed. The aims of this study were (1) to quantify antimicrobial use in the study population using different units of measurement and contrast the results obtained, (2) to evaluate data quality of farm records on antimicrobial use, and (3) to compare data quality of different recording systems. During 1 year, data on antimicrobial use were collected from 97 dairy farms. Antimicrobial consumption was quantified using: (1) the incidence density of antimicrobial treatments; (2) the weight of active substance; (3) the used daily dose and (4) the used course dose for antimicrobials for intestinal, intrauterine and systemic use; and (5) the used unit dose, for antimicrobials for intramammary use. Data quality was evaluated by describing completeness and accuracy of the recorded information, and by comparing farmers' and veterinarians' records. Relative consumption of antimicrobials depended on the unit of measurement: used doses reflected the treatment intensity better than weight of active substance. The use of antimicrobials classified as high priority was low, although under- and overdosing were frequently observed. Electronic recording systems allowed better traceability of the animals treated. Recording drug name or dosage often resulted in incomplete or inaccurate information. Veterinarians tended to record more drugs than farmers. The integration of veterinarian and farm data would improve data quality.

The Lily and the Lotus: Notes on Translation

This critical/creative project considers Stéphane Mallarmé’s critical poems in his 1897 Divagations as an invitation to explore the notion of criticism and the relationship between the conceptual and the nonconceptual aspects of writing and thinking. Informed by Emmanuel Levinas’s ethics of the face, Walter Benjamin’s essay “The Task of theTranslator” and the myth of Orpheus, I consider ways to approach that which may not be said or thought by following Mallarmé’s method of combining poetry and criticism to create a wandering, unclassifiable text where we may imagine the nonconceptual as a remoteness, as the presence of an absence.

Factors influencing subjective quality of life in patients with schizophrenia and other mental disorders: a pooled analysis

Subjective quality of life (SQOL) is an important outcome in the treatment of patients with schizophrenia. However, there is only limited evidence on factors influencing SQOL, and little is known about whether the same factors influence SQOL in patients with schizophrenia and other mental disorders. This study aimed to identify the factors associated with SQOL and test whether these factors are equally important in schizophrenia and other disorders. For this we used a pooled data set obtained from 16 studies that had used either the Lancashire Quality of Life Profile or the Manchester Short Assessment of Quality of Life for assessing SQOL. The sample comprised 3936 patients with schizophrenia, mood disorders, and neurotic disorders. After controlling for confounding factors, within-subject clustering, and heterogeneity of findings across studies in linear mixed models, patients with schizophrenia had more favourable SQOL scores than those with mood and neurotic disorders. In all diagnostic groups, older patients, those in employment, and those with lower symptom scores had higher SQOL scores. Whilst the strength of the association between age and SQOL did not differ across diagnostic groups, symptom levels were more strongly associated with SQOL in neurotic than in mood disorders and schizophrenia. The association of employment and SQOL was stronger in mood and neurotic disorders than in schizophrenia. The findings may inform the use and interpretation of SQOL data for patients with schizophrenia.

Tolerance and Critical Thinking

Post-soviet countries are in the process of transformation from a totalitarian order to a democratic one, a transformation which is impossible without a profound shift in people's way of thinking. The group set themselves the task of determining the essence of this shift. Using a multidisciplinary approach, they looked at concrete ways of overcoming the totalitarian mentality and forming that necessary for an open democratic society. They studied the contemporary conceptions of tolerance and critical thinking and looked for new foundations of criticism, especially in hermeneutics. They then sought to substantiate the complementary relation between tolerance and criticism in the democratic way of thinking and to prepare a a syllabus for teaching on the subject in Ukrainian higher education. In a philosophical exploration of tolerance they began with relgious tolerance as its first and most important form. Political and social interests often lay at the foundations of religious intolerance and this implicitly comprised the transition to religious tolerance when conditions changed. Early polytheism was more or less indifferent to dogmatic deviations but monotheism is intolerant of heresies. The damage wrought by the religious wars of the Reformations transformed tolerance into a value. They did not create religious tolerance but forced its recognition as a positive phenomenon. With the weakening of religious institutions in the modern era, the purely political nature of many conflicts became evident and this stimulated the extrapolation of tolerance into secular life. Each historical era has certain acts and operations which may be interpreted as tolerant and these can be classified as to whether or not they are based on the conscious following of the principle of tolerance. This criterion requires the separation of the phenomenon of tolerance from its concept and from tolerance as a value. Only the conjunction of a concept of tolerance with a recognition of its value can transform it into a principle dictating a norm of conscious behaviour. The analysis of the contemporary conception of tolerance focused on the diversity of the concept and concluded that the notions used cannot be combined in the framework of a single more or less simple classification, as the distinctions between them are stimulated by the complexity of the realty considered and the variety of its manifestations. Notions considered in relation to tolerance included pluralism, respect and particular-universal. The rationale of tolerance was also investigated and the group felt that any substantiation of the principle of tolerance must take into account human beings' desire for knowledge. Before respecting or being tolerant of another person different from myself, I should first know where the difference lies, so knowledge is a necessary condition of tolerance.The traditional division of truth into scientific (objective and unique) and religious, moral, political (subjective and so multiple) intensifies the problem of the relationship between truth and tolerance. Science was long seen as a field of "natural" intolerance whereas the validity of tolerance was accepted in other intellectual fields. As tolerance eemrges when there is difference and opposition, it is essentially linked with rivaly and there is a a growing recognition today that unlimited rivalry is neither able to direct the process of development nor to act as creative matter. Social and economic reality has led to rivalry being regulated by the state and a natural requirement of this is to associate tolerance with a special "purified" form of rivalry, an acceptance of the actiivity of different subjects and a specification of the norms of their competition. Tolerance and rivalry should therefore be subordinate to a degree of discipline and the group point out that discipline, including self-discipline, is a regulator of the balance between them. Two problematic aspects of tolerance were identified: why something traditionally supposed to have no positive content has become a human activity today, and whether tolerance has full-scale cultural significance. The resolution of these questions requires a revision of the phenomenon and conception of tolerance to clarify its immanent positive content. This involved an investigation of the contemporary concept of tolerance and of the epistemological foundations of a negative solution of tolerance in Greek thought. An original soution to the problem of the extrapolation of tolerance to scientific knowledge was proposed based on the Duhem-Quine theses and conceptiion of background knowledge. In this way tolerance as a principle of mutual relations between different scientific positions gains an essential epistemological rationale and so an important argument for its own universal status. The group then went on to consider the ontological foundations for a positive solution of this problem, beginning with the work of Poincare and Reichenbach. The next aspect considered was the conceptual foundations of critical thinking, looking at the ideas of Karl Popper and St. Augustine and at the problem of the demarcation line between reasonable criticism and apologetic reasoning. Dogmatic and critical thinking in a political context were also considered, before an investigation of critical thinking's foundations. As logic is essential to critical thinking, the state of this discipline in Ukrainian and Russian higher education was assessed, together with the limits of formal-logical grounds for criticism, the role of informal logical as a basis for critical thinking today, dialectical logic as a foundation for critical thinking and the universality of the contemporary demand for criticism. The search for new foundations of critical thinking covered deconstructivism and critical hermeneutics, including the problem of the author. The relationship between tolerance and criticism was traced from the ancient world, both eastern and Greek, through the transitional community of the Renaissance to the industrial community (Locke and Mill) and the evolution of this relationship today when these are viewed not as moral virtues but as ordinary norms. Tolerance and criticism were discussed as complementary manifestations of human freedom. If the completeness of freedom were accepted it would be impossible to avoid recognition of the natural and legal nature of these manifestations and the group argue that critical tolerance is able to avoid dismissing such negative phenomena as the degradation of taste and manner, pornography, etc. On the basis of their work, the group drew up the syllabus of a course in "Logic with Elements of Critical Thinking, and of a special course on the "Problem of Tolerance".

Practical sources of error in measuring pulmonary artery occlusion pressure: a study in participants of a special intensivist training program of The Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI)

BACKGROUND: Physiological data obtained with the pulmonary artery catheter (PAC) are susceptible to errors in measurement and interpretation. Little attention has been paid to the relevance of errors in hemodynamic measurements performed in the intensive care unit (ICU). The aim of this study was to assess the errors related to the technical aspects (zeroing and reference level) and actual measurement (curve interpretation) of the pulmonary artery occlusion pressure (PAOP). METHODS: Forty-seven participants in a special ICU training program and 22 ICU nurses were tested without pre-announcement. All participants had previously been exposed to the clinical use of the method. The first task was to set up a pressure measurement system for PAC (zeroing and reference level) and the second to measure the PAOP. RESULTS: The median difference from the reference mid-axillary zero level was - 3 cm (-8 to + 9 cm) for physicians and -1 cm (-5 to + 1 cm) for nurses. The median difference from the reference PAOP was 0 mmHg (-3 to 5 mmHg) for physicians and 1 mmHg (-1 to 15 mmHg) for nurses. When PAOP values were adjusted for the differences from the reference transducer level, the median differences from the reference PAOP values were 2 mmHg (-6 to 9 mmHg) for physicians and 2 mmHg (-6 to 16 mmHg) for nurses. CONCLUSIONS: Measurement of the PAOP is susceptible to substantial error as a result of practical mistakes. Comparison of results between ICUs or practitioners is therefore not possible.

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalizability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies.The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers.This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated web site (http://www.strobe-statement.org) should be helpful resources to improve reporting of observational research.

Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research.

Visual and quantitative electroencephalographic analysis of healthy young and adult cats under medetomidine sedation

A study was designed to investigate the effect of medetomidine sedation on quantitative electroencephalography (q-EEG) in healthy young and adult cats to determine objective guidelines for diagnostic EEG recordings and interpretation. Preliminary visual examination of EEG recordings revealed high-voltage low-frequency background activity. Spindles, k-complexes and vertex sharp transients characteristic of sleep or sedation were superimposed on a low background activity. Neither paroxysmal activity nor EEG burst-suppression were observed. The spectral analysis of q-EEG included four parameters, namely, relative power (%), and mean, median and peak frequency (Hz) of all four frequency bands (delta, theta, alpha and beta). The findings showed a prevalence of slow delta and theta rhythms as opposed to fast alpha and beta rhythms in both young (group A) and adult (group B) cats. A posterior gradient was reported for the theta band and an anterior gradient for the alpha and beta bands in both groups, respectively. The relative power value in group B compared to group A was significantly higher for theta, alpha and beta bands, and lower for the delta band. The mean and median frequency values in group B was significantly higher for delta, theta and beta bands and lower for the alpha band. The study has shown that a medetomidine sedation protocol for feline EEG may offer a method for investigating bio-electrical cortical activity. The use of q-EEG analysis showed a decrease in high frequency bands and increased activity of the low frequency band in healthy cats under medetomidine sedation.

[Strengthening the reporting of observational studies in epidemiology (STROBE): explanation and elaboration]

Much medical research is observational. The reporting of observational studies is often of insufficient quality. Poor reporting hampers the assessment of the strengths and weaknesses of a study and the generalisability of its results. Taking into account empirical evidence and theoretical considerations, a group of methodologists, researchers, and editors developed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) recommendations to improve the quality of reporting of observational studies. The STROBE Statement consists of a checklist of 22 items, which relate to the title, abstract, introduction, methods, results and discussion sections of articles. Eighteen items are common to cohort studies, case-control studies and cross-sectional studies and four are specific to each of the three study designs. The STROBE Statement provides guidance to authors about how to improve the reporting of observational studies and facilitates critical appraisal and interpretation of studies by reviewers, journal editors and readers. This explanatory and elaboration document is intended to enhance the use, understanding, and dissemination of the STROBE Statement. The meaning and rationale for each checklist item are presented. For each item, one or several published examples and, where possible, references to relevant empirical studies and methodological literature are provided. Examples of useful flow diagrams are also included. The STROBE Statement, this document, and the associated Web site (http://www.strobe-statement.org/) should be helpful resources to improve reporting of observational research.

Market, Management and Profession. Social Business in the Polder

In a recent policy document of the organized employers in the care and welfare sector in The Netherlands (the MO Group), directors and board members of care and welfare institutions present themselves as "social entrepreneurs", managing their institutions as look-a like commercial companies. They are hardly criticized and there is not any countervailing power of significance. The workers are focusing on their own specialized professional fields and divided as a whole. Many government officials are in favour or do not bother. The relatively small number of intellectual workers in Dutch care and welfare are fragmented and pragmatic. From a democratic point of view this is a worrying situation. From a professional point of view the purpose and functions of professional care and welfare work are at stake. The penetration of market mechanisms and the take-over by commercially orientated managers result from unquestioned adaptation of Anglo-Saxon policy in The Netherlands in the 1990's, following the crisis of the Welfare State in the late 1980's. The polder country is now confronted fully with the pressure and negative effects of unbalanced powers in the institutions, i.e. Managerialism. After years of silence, the two principal authentic critics of Dutch care and welfare, Harry Kunneman and Andries Baart, are no longer voices crying in the wilderness, but are getting a response from a growing number of worried workers and intellectuals. Kunneman and Baart warn against the restriction of professional space and the loss of normative values and standards in the profession. They are right. It is high time to make room for criticism and to start a debate about the future of the social professions in The Netherlands, better: in Europe. Research, discussion and action have to prove how worrying the everyday situation of professional workers is, what goals have to be set and what strategy to be chosen.

Legal Translation and the Bilingual Publication of Roman Imperial Constitutions

The present paper aims at investigating translation techniques and publication methods of Roman imperial constitutions published in Greek in the eastern provinces of the empire, where the official Latin was not well-established. Language, being a tool for normative communication must be comprehensible to the addressees of the norm, therefore publication of a normative text in a multilingual society brings along difficulties related in particular to the translatability of legal terminology. Language problems appear, however, not only in the level of communication, but also in those of implementation and interpretation of norms. Linguistic diversity, which currently afflicts legislators in the EU, has already been a challenge for the legislators in the Roman Empire. Major difficulty was the necessity of expressing Roman legal concepts in Greek language. Centralized translation system and consequent use of terminology helped to adapt Greek for the purposes of Roman legislator creating new technical vocabulary.

Vancomycin: Predictive risk factors for nephrotoxicity and implication for monitoring

The increased use of vancomycin in hospitals has resulted in a standard practice to monitor serum vancomycin levels because of possible nephrotoxicity. However, the routine monitoring of vancomycin serum concentration is under criticism and the cost effectiveness of such routine monitoring is in question because frequent monitoring neither results in increase efficacy nor decrease nephrotoxicity. The purpose of the present study is to determine factors that may place patients at increased risk of developing vancomycin induced nephrotoxicity and for whom monitoring may be most beneficial.^ From September to December 1992, 752 consecutive in patients at The University of Texas M. D. Anderson Cancer Center, Houston, were prospectively evaluated for nephrotoxicity in order to describe predictive risk factors for developing vancomycin related nephrotoxicity. Ninety-five patients (13 percent) developed nephrotoxicity. A total of 299 patients (40 percent) were considered monitored (vancomycin serum levels determined during the course of therapy), and 346 patients (46 percent) were receiving concurrent moderate to highly nephrotoxic drugs.^ Factors that were found to be significantly associated with nephrotoxicity in univariate analysis were: gender, base serum creatinine greater than 1.5mg/dl, monitor, leukemia, concurrent moderate to highly nephrotoxic drugs, and APACHE III scores of 40 or more. Significant factors in the univariate analysis were then entered into a stepwise logistic regression analysis to determine independent predictive risk factors for vancomycin induced nephrotoxicity.^ Factors, with their corresponding odds ratios and 95% confidence limits, selected by stepwise logistic regression analysis to be predictive of vancomycin induced nephrotoxicity were: Concurrent therapy with moderate to highly nephrotoxic drugs (2.89; 1.76-4.74), APACHE III scores of 40 or more (1.98; 1.16-3.38), and male gender (1.98; 1.04-2.71).^ Subgroup (monitor and non-monitor) analysis showed that male (OR = 1.87; 95% CI = 1.01, 3.45) and moderate to highly nephrotoxic drugs (OR = 4.58; 95% CI = 2.11, 9.94) were significant for nephrotoxicity in monitored patients. However, only APACHE III score (OR = 2.67; 95% CI = 1.13,6.29) was significant for nephrotoxicity in non-monitored patients.^ The conclusion drawn from this study is that not every patient receiving vancomycin therapy needs frequent monitoring of vancomycin serum levels. Such routine monitoring may be appropriate in patients with one or more of the identified risk factors and low risk patients do not need to be subjected to the discomfort and added cost of multiple blood sampling. Such prudent selection of patients to monitor may decrease cost to patients and hospital. ^

The missing link between clinical states and biomarkers in mental disorders

Current diagnostic definitions of psychiatric disorders based on collections of symptoms encompass very heterogeneous populations and are thus likely to yield spurious results when exploring biological correlates of mental disturbances. It has been suggested that large studies of biomarkers across diagnostic entities may yield improved clinical information. Such a view is based on the concept of assessment as a collection of symptoms devoid of any clinical judgment and interpretation. Yet, important advances have been made in recent years in clinimetrics, the science of clinical judgment. The current clinical taxonomy in psychiatry, which emphasizes reliability at the cost of clinical validity, does not include effects of comorbid conditions, timing of phenomena, rate of progression of an illness, responses to previous treatments, and other clinical distinctions that demarcate major prognostic and therapeutic differences among patients who otherwise seem to be deceptively similar since they share the same psychiatric diagnosis. Clinimetrics may provide the missing link between clinical states and biomarkers in psychiatry, building pathophysiological bridges from clinical manifestations to their neurobiological counterparts.

The significant effect of endometriosis on physical, mental and social wellbeing: results from an international cross-sectional survey.

STUDY QUESTION To what extent do the management of endometriosis and the symptoms that remain after treatment affect the quality of life in women with the disease? SUMMARY ANSWER Many women with endometriosis had impaired quality of life and continued to suffer from endometriosis-associated symptoms even though their endometriosis has been managed in tertiary care centres. WHAT IS KNOWN ALREADY The existing literature indicates that quality of life and work productivity is reduced in women with endometriosis. However, most studies have small sample sizes, are treatment related or examine newly diagnosed patients only. STUDY DESIGN, SIZE, DURATION A cross-sectional questionnaire-based survey among 931 women with endometriosis treated in 12 tertiary care centres in 10 countries. PARTICIPANTS/MATERIALS, SETTING, METHODS Women diagnosed with endometriosis who had at least one contact related to endometriosis-associated symptoms during 2008 with a participating centre were enrolled into the study. The study investigated the effect of endometriosis on education, work and social wellbeing, endometriosis-associated symptoms and health-related quality of life, by using questions obtained from the World Endometriosis Research Foundation (WERF) GSWH instrument (designed and validated for the WERF Global Study on Women's Health) and the Short Form 36 version 2 (SF-36v2). MAIN RESULTS AND THE ROLE OF CHANCE Of 3216 women invited to participate in the study, 1450 (45%) provided informed consent and out of these, 931 (931/3216 = 29%) returned the questionnaires. Endometriosis had affected work in 51% of the women and affected relationships in 50% of the women at some time during their life. Dysmenorrhoea was reported by 59%, dyspareunia by 56% and chronic pelvic pain by 60% of women. Quality of life was decreased in all eight dimensions of the SF-36v2 compared with norm-based scores from a general US population (all P < 0.01). Multivariate regression analysis showed that number of co-morbidities, chronic pain and dyspareunia had an independent negative effect on both the physical and mental component of the SF-36v2. LIMITATIONS, REASONS FOR CAUTION The fact that women were enrolled in tertiary care centres could lead to a possible over-representation of women with moderate-to-severe endometriosis, because the participating centres typically treat more complex and referred cases of endometriosis. The response rate was relatively low. Since there was no Institute Review Board approval to do a non-responder investigation on basic characteristics, some uncertainty remains regarding the representativeness of the investigated population. WIDER IMPLICATIONS OF THE FINDINGS This international multicentre survey represents a large group of women with endometriosis, in all phases of the disease, which increases the generalizability of the data. Women still suffer from frequent symptoms, despite tertiary care management, in particular chronic pain and dyspareunia. As a result their quality of life is significantly decreased. A patient-centred approach with extensive collaboration across disciplines, such as pain specialists, psychologists, sexologists and social workers, may be a valuable strategy to improve the long-term care of women with endometriosis. STUDY FUNDING/COMPETING INTEREST(S) The WERF EndoCost study is funded by the World Endometriosis Research Foundation (WERF) through grants received from Bayer Schering Pharma AG, Takeda Italia Farmaceutici SpA, Pfizer Ltd and the European Society of Human Reproduction and Embryology. The sponsors did not have a role in the design and conduct of the study; collection, management, analysis and interpretation of the data; and preparation, review or approval of the manuscript. L.H. is the chief executive and T.D. was a board member of WERF at the time of funding. T.D. holds the Merck-Serono Chair in Reproductive Medicine and Surgery, and the Ferring Chair in Reproductive Medicine at the Katholieke Universiteit Leuven in Belgium and has served as consultant/research collaborator for Merck-Serono, Schering-Plough, Astellas and Arresto.