Statistical Editor Research Articles

Standardizing definitions and reporting guidelines for the infertility core outcome set: an international consensus development study† ‡.

STUDY QUESTIONCan consensus definitions for the core outcome set for infertility be identified in order to recommend a standardized approach to reporting?SUMMARY ANSWERConsensus definitions for individual core outcomes, contextual statements and a standardized reporting table have been developed.WHAT IS KNOWN ALREADYDifferent definitions exist for individual core outcomes for infertility. This variation increases the opportunities for researchers to engage with selective outcome reporting, which undermines secondary research and compromises clinical practice guideline development.STUDY DESIGN, SIZE, DURATIONPotential definitions were identified by a systematic review of definition development initiatives and clinical practice guidelines and by reviewing Cochrane Gynaecology and Fertility Group guidelines. These definitions were discussed in a face-to-face consensus development meeting, which agreed consensus definitions. A standardized approach to reporting was also developed as part of the process.PARTICIPANTS/MATERIALS, SETTING, METHODSHealthcare professionals, researchers and people with fertility problems were brought together in an open and transparent process using formal consensus development methods.MAIN RESULTS AND THE ROLE OF CHANCEForty-four potential definitions were inventoried across four definition development initiatives, including the Harbin Consensus Conference Workshop Group and International Committee for Monitoring Assisted Reproductive Technologies, 12 clinical practice guidelines and Cochrane Gynaecology and Fertility Group guidelines. Twenty-seven participants, from 11 countries, contributed to the consensus development meeting. Consensus definitions were successfully developed for all core outcomes. Specific recommendations were made to improve reporting.LIMITATIONS, REASONS FOR CAUTIONWe used consensus development methods, which have inherent limitations. There was limited representation from low- and middle-income countries.WIDER IMPLICATIONS OF THE FINDINGSA minimum data set should assist researchers in populating protocols, case report forms and other data collection tools. The generic reporting table should provide clear guidance to researchers and improve the reporting of their results within journal publications and conference presentations. Research funding bodies, the Standard Protocol Items: Recommendations for Interventional Trials statement, and over 80 specialty journals have committed to implementing this core outcome set.STUDY FUNDING/COMPETING INTEREST(S)This research was funded by the Catalyst Fund, Royal Society of New Zealand, Auckland Medical Research Fund and Maurice and Phyllis Paykel Trust. Siladitya Bhattacharya reports being the Editor-in-Chief of Human Reproduction Open and an editor of the Cochrane Gynaecology and Fertility Group. J.L.H.E. reports being the Editor Emeritus of Human Reproduction. R.S.L. reports consultancy fees from Abbvie, Bayer, Ferring, Fractyl, Insud Pharma and Kindex and research sponsorship from Guerbet and Hass Avocado Board. B.W.M. reports consultancy fees from Guerbet, iGenomix, Merck, Merck KGaA and ObsEva. C.N. reports being the Editor-in-Chief of Fertility and Sterility and Section Editor of the Journal of Urology, research sponsorship from Ferring, and a financial interest in NexHand. E.H.Y.N. reports research sponsorship from Merck. A.S. reports consultancy fees from Guerbet. J.W. reports being a statistical editor for the Cochrane Gynaecology and Fertility Group. A.V. reports that he is a Statistical Editor of the Cochrane Gynaecology & Fertility Review Group and of the journal Reproduction. His employing institution has received payment from Human Fertilisation and Embryology Authority for his advice on review of research evidence to inform their ‘traffic light’ system for infertility treatment ‘add-ons’. N.L.V. reports consultancy and conference fees from Ferring, Merck and Merck Sharp and Dohme. The remaining authors declare no competing interests in relation to the work presented. All authors have completed the disclosure form.TRIAL REGISTRATION NUMBERCore Outcome Measures in Effectiveness Trials Initiative: 1023.

Urinary Phosphate Excretion and Microvascular Function in a Population-Based Cohort

Urinary Phosphate Excretion and Microvascular Function in a Population-Based Cohort

Statistical Guideline #6. Indicate magnitude and precision in your estimation and use "new statistics".

This is one in a series of statistical guidelines designed to highlight common statistical considerations in behavioral medicine research. The goal is to briefly discuss appropriate ways to analyze and present data in the International Journal of Behavioral Medicine (IJBM). Collectively, the series will culminate in a set of basic statistical guidelines to be adopted by IJBM and integrated into the journal's official Instructions for Authors, and also to serve as an independent resource. If you have ideas for a future topic, please email the Statistical Editor, Suzanne Segerstrom at segerstrom@uky.edu.

Pathways to health: conceptual clarification and appropriate statistical treatment of mediator, moderator, and indirect effects using examples from burnout research

In my role as consulting statistical editor for the South African Journal of Psychology, I have witnessed a steady increase in articles that focused on the presumed role of mediator and moderator variables. While straightforward cause–effect studies have an important explanatory role, our task in the helping profession is to identify those factors that ‘intervene’ and make individuals differentially vulnerable in the cause–effect relationship. However, in a significant number of papers I have reviewed, there appeared to be considerable conceptual confusion about these variables with moderator and mediator often used interchangeably. In addition, no single paper I have reviewed considered indirect effects. This article attempts to differentiate between the various roles that a third variable can play in the adverse condition–wellbeing relationship (e.g., the stress–depression relationship). In addition, the appropriate statistical procedures for testing these roles are demonstrated using burnout research data. In this particular research project, 207 secondary school teachers completed a range of research questionnaires designed to assess among others burnout, work environment, social support, personal competence, coping, and problem-solving appraisal. Using this data, the various roles that third variables can play are demonstrated using hierarchical regression analyses.

Reviewer Blinding in Peer Review

Reviewer Blinding in Peer Review

Statistical Guideline No. 5. Include Results of a Power Analysis; if a Power Analysis Was Not Performed, Describe the Stopping Rule for Recruitment.

This is one in a series of statistical guidelines designed to highlight common statistical considerations in behavioral medicine research. The goal is to briefly discuss appropriate ways to analyze and present data in the International Journal of Behavioral Medicine (IJBM). Collectively the series will culminate in a set of basic statistical guidelines to be adopted by IJBM and integrated into the journal's official Instructions for Authors, and also to serve as an independent resource. If you have ideas for a future topic, please email the Statistical Editor, Suzanne Segerstrom at segerstrom@uky.edu.

Statistical Guideline #4. Describe the Nature and Extent of Missing Data and Impute Where Possible and Prudent.

From the Editors: This is one in a series of statistical guidelines designed to highlight common statistical considerations in behavioral medicine research. The goal is to briefly discuss appropriate ways to analyze and present data in the International Journal of Behavioral Medicine (IJBM). Collectively the series will culminate in a set of basic statistical guidelines to be adopted by IJBM and integrated into the journal's official Instructions for Authors, but also to serve as an independent resource. If you have ideas for a future topic, please email the Statistical Editor Suzanne Segerstrom at segerstrom@uky.edu.

Statistical Guideline #3: Designate and Justify Covariates A Priori, and Report Results With and Without Covariates.

From the Editors: This is one in a series of statistical guidelines designed to highlight common statistical considerations in behavioral medicine research. The goal was to briefly discuss appropriate ways to analyze and present data in the International Journal of Behavioral Medicine (IJBM). Collectively, the series will culminate in a set of basic statistical guidelines to be adopted by IJBM and integrated into the journal's official Instructions for Authors and also to serve as an independent resource. If you have ideas for a future topic, please email the Statistical Editor, Suzanne Segerstrom at segerstrom@uky.edu.

Statistical Guideline #2: Report Appropriate Reliability for your Sample, Measure, and Design.

From the Editors: This is the second column from the Statistics Guru. The Statistics Guru will appear in every issue. In these columns, we briefly discuss appropriate ways to analyze and present data in the journal. As such, the Statistics Guru can be seen both as an editorial amuse bouche and a set of guidelines for reporting data in the International Journal of Behavioral Medicine. If you have ideas for a column, please email the Statistical Editor, Suzanne Segerstrom at segerstrom@uky.edu.

A Cognitive Linguistic Study of the English Preposition 'in'

The present study aims at analyzing the polysemy of the English preposition in from the cognitive linguistic (CL) point of view using Evans' and Tyler's approach (2003). The perplexity faced by Iraqi second language learners (L2) due to the multi-usages of this preposition has motivated the researcher to conduct this study. Seventy-six second year university students participated in this experimental study. The data of the pre-test and post-test were analyzed by SPSS statistical editor. The results have shown the following: First, a progress of more than (0.05≤) has been detected as far as students' understanding of the multiple usages of the preposition in is concerned. Second, the results of the questionnaire have shown a prominent positive change in the students' attitude toward CL approach. Third, the main source of difficulty has been shown to be attributed to the diversity in the semantics of the preposition in. Fourth, CL as an approach has proven its effectiveness in accurately comprehending the semantics of the English preposition in.

A Cognitive Linguistic Study of the English Preposition 'in'

The present study aims at analyzing the polysemy of the English preposition in from the cognitive linguistic (CL) point of view using Evans' and Tyler's approach (2003). The perplexity faced by Iraqi second language learners (L2) due to the multi-usages of this preposition has motivated the researcher to conduct this study. Seventy-six second year university students participated in this experimental study. The data of the pre-test and post-test were analyzed by SPSS statistical editor. The results have shown the following: First, a progress of more than (0.05≤) has been detected as far as students' understanding of the multiple usages of the preposition in is concerned. Second, the results of the questionnaire have shown a prominent positive change in the students' attitude toward CL approach. Third, the main source of difficulty has been shown to be attributed to the diversity in the semantics of the preposition in. Fourth, CL as an approach has proven its effectiveness in accurately comprehending the semantics of the English preposition in.

Are interventions in reproductive medicine assessed for plausible and clinically relevant effects? A systematic review of power and precision in trials and meta-analyses.

STUDY QUESTIONHow much statistical power do randomised controlled trials (RCTs) and meta-analyses have to investigate the effectiveness of interventions in reproductive medicine?SUMMARY ANSWERThe largest trials in reproductive medicine are unlikely to detect plausible improvements in live birth rate (LBR), and meta-analyses do not make up for this shortcoming.WHAT IS KNOWN ALREADYEffectiveness of interventions is best evaluated using RCTs. In order to be informative, these trials should be designed to have sufficient power to detect the smallest clinically relevant effect. Similar trials can subsequently be pooled in meta-analyses to more precisely estimate treatment effects.STUDY DESIGN, SIZE, DURATIONA review of power and precision in 199 RCTs and meta-analyses from 107 Cochrane Reviews was conducted.PARTICIPANTS/MATERIALS, SETTING, METHODSSystematic reviews published by Cochrane Gynaecology and Fertility with the primary outcome live birth were identified. For each live birth (or ongoing pregnancy) meta-analysis and for the largest RCT in each, we calculated the power to detect absolute improvements in LBR of varying sizes. Additionally, the 95% CIs of estimated treatment effects from each meta-analysis and RCT were recorded, as these indicate the precision of the result.MAIN RESULTS AND THE ROLE OF CHANCEMedian (interquartile range) power to detect an improvement in LBR of 5 percentage points (pp) (e.g. 25–30%) was 13% (8–21%) for RCTs and 16% (9–33%) for meta-analyses. No RCTs and only 2% of meta-analyses achieved 80% power to detect an improvement of 5 pp. Median power was high (85% for trials and 93% for meta-analyses) only in relation to 20 pp absolute LBR improvement, although substantial numbers of trials and meta-analyses did not achieve 80% power even for this improbably large effect size. Median width of 95% CIs was 25 pp and 21 pp for RCTs and meta-analyses, respectively. We found that 28% of Cochrane Reviews with LBR as the primary outcome contain no live birth (or ongoing pregnancy) data.LARGE-SCALE DATAThe data used in this study may be accessed at https://osf.io/852tn/?view_only=90f1579ce72747ccbe572992573197bd.LIMITATIONS, REASONS FOR CAUTIONThe design and analysis decisions used in this study are predicted to overestimate the power of trials and meta-analyses, and the size of the problem is therefore likely understated. For some interventions, it is possible that larger trials not reporting live birth or ongoing pregnancy have been conducted, which were not included in our sample. In relation to meta-analyses, we calculated power as though all participants were included in a single trial. This ignores heterogeneity between trials in a meta-analysis, and will cause us to overestimate power.WIDER IMPLICATIONS OF THE FINDINGSTrials capable of detecting realistic improvements in LBR are lacking in reproductive medicine, and meta-analyses are not large enough to overcome this deficiency. This situation will lead to unwarranted pessimism as well as unjustified enthusiasm regarding reproductive interventions, neither of which are consistent with the practice of evidence-based medicine or the idea of informed patient choice. However, RCTs and meta-analyses remain vital to establish the effectiveness of fertility interventions. We discuss strategies to improve the evidence base and call for collaborative studies focusing on the most important research questions.STUDY FUNDING/COMPETING INTEREST(S)There was no specific funding for this study. KS and SL declare no conflict of interest. AV consults for the Human Fertilisation and Embryology Authority (HFEA): all fees are paid directly to AV’s employer. JW declares that publishing research benefits his career. SR is a Statistical Editor for Human Reproduction. JW and AV are Statistical Editors for Cochrane Gynaecology and Fertility. DRB is funded by the NHS as Scientific Director of a clinical IVF service.PROSPERO REGISTRATION NUMBERNone.

Cognitive Comprehension of “Beyond & Behind”: An Experimental Study of Baghdad University

The present study analyzes two locative English prepositions behind and beyond from the cognitive semantic point of view. These prepositions pose a problem experienced by Iraqi undergraduates. The complexity of these two prepositions encourages the researcher to use the cognitive linguistics (CL) approach and its insights as developed by Evans and Tyler 2003 to test its validity and help the Iraqi students. The data analysis is quantitatively-based. Seventy second-year university students participate in this experimental study. The pre-test and post-test data are analyzed through SPSS statistical editor and the results show a progress of more than (0.05≤). The results of the questionnaire show a noticeable positive change in the students’ attitude toward CL approach and display the main source of difficulty that is related to perplexity in the usage of these prepositions. The effectiveness of CL approach in getting accurate comprehension of the English prepositions behind and beyond is proved by the results of this experiment.

In Reply.

We appreciate the message from Drs. Klein, Yentis, and Clyburn in response to our Editorial in Anesthesiology1 and our Letter to the Editor in Anaesthesia.2 Clearly all correspondents are dedicated to scientific integrity in research.Dr. Kharasch is Editor-in-Chief and Dr. Houle is Statistical Editor for Anesthesiology.

New Statistical Editor—February 2018

New Statistical Editor—February 2018

Tips for Analyzing Large Data Sets From the JAMA Surgery Statistical Editors

Tips for Analyzing Large Data Sets From the JAMA Surgery Statistical Editors

New Statistical Editor—January 2018

New Statistical Editor—January 2018

How much variation in oocyte yield after controlled ovarian stimulation can be explained? A multilevel modelling study.

STUDY QUESTIONHow much variation in oocyte yield after controlled ovarian stimulation (COS) can be accounted for by known patient and treatment characteristics?SUMMARY ANSWERThere is substantial variation in the COS responses of similar women and in repeated COS episodes undertaken by the same woman, which cannot be accounted for at present.WHAT IS ALREADY KNOWNThe goal of individualized COS is to safely collect enough oocytes to maximize the chance of success in an ART cycle. Personalization of treatment rests on the ability to reduce variation in response through modifiable factors.STUDY DESIGN, SIZE, DURATIONMultilevel modelling of a routine ART database covering the period 1 October 2008–8 August 2012 was employed to estimate the amount of variation in COS response and the extent to which this could be explained by immutable patient characteristics and by manipulable treatment variables. A total of 1851 treatment cycles undertaken by 1430 patients were included. The study was not subject to attrition, as cancelled cycles were included in the analysis.PARTICIPANTS/MATERIALS, SETTING, METHODSWomen aged 21–43 years undergoing ovarian stimulation for IVF (possibly with ICSI) using their own eggs at a tertiary care centre.MAIN RESULTS AND THE ROLE OF CHANCESubstantial unexplained variation in COS response (oocyte yield): was observed (3.4-fold (95% CI: 3.12 to 3.61)). Only a relatively small amount of this variation (around 19%) can be explained by modifiable factors. A significant, previously undescribed predictor of response was the practitioner performing oocyte retrieval, with 1.5-fold variation between surgeons with the highest and lowest yields.LIMITATIONS REASONS FOR CAUTIONAlthough a large number of covariables were adjusted for in the analysis, including those that were used for dosing and determination of the stimulation regimen, this study is subject to confounding due to unmeasured variables and measurement error.WIDER IMPLICATIONS OF THE FINDINGSThe present study suggests that there are limits to the extent that COS response can be predicted on the basis of known factors, or controlled by manipulation of treatment factors. Moreover, modifiable variation in response appears to be partially attributable to differences between surgeons performing oocyte retrieval. Consequently, consistent prevention of ineffective or unsafe responses to COS is not likely to be possible at present. Our results highlight the importance of blinding surgeons in RCTs. The data also suggest that there is likely to be limited scope for personalized treatment unless additional predictors of ovarian response can be identified.STUDY FUNDING/COMPETING INTERESTSJ.W. is funded by a Doctoral Research Fellowship from the National Institute for Health Research (DRF-2014-07-050) supervised by S.A.R. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health. J.W. is a statistical editor of the Cochrane Gynaecology and Fertility Group. S.A.R. is a statistical editor for Human Reproduction. J.W. also declares that publishing peer-reviewed articles benefits his career. A.L.M. has received consultation fees from MSD, Merck Serono, Ferring, TEVA, Roche, Beckman Coulter.

Quantitative Assessment of Statistical Reviews of Patient Safety Research Articles.

For 8.5 consecutive years, all patient safety articles of a journal underwent statistical review before publication. We sought to establish the prevalence of statistical themes in the statistical reviews, consideration of contemporary statistical methods, and their associations with time to journal receipt of authors' revision. An initial set of statistical themes was created using the statistical editor's notes. For example, for the statistical theme of "CONSORT checklist," the search term needed was "CONSORT." A complete (exhaustive) list of additional themes was obtained inductively. Among the 273 subsequent reviews for manuscripts that were ultimately accepted, the number of paragraphs that included a theme of a statistical method was only weakly associated with longer revision times (Kendall τ = 0.139 ± 0.039, P = 0.0004). Among the total 3274 paragraphs of statistical reviews, 72.2% did not include a theme of a statistical method (e.g., the editor instead asked the authors to clarify what statistical method had been used) (95% confidence interval [CI] = 70.6%-73.7%, P < 0.0001 versus 50%).Among the 207 manuscripts with a review that included a statistical method, 47.3% included a contemporary topic (e.g., generalized pivotal methods) (95% CI = 40.4%-54.4%). However, among the 911 corresponding paragraphs of statistical review comments, only 16.0% included a contemporary theme (95% CI = 13.7%-18.6%). The revised versions of patient safety articles, which are eventually to be accepted for publication, have many statistical limitations especially in the reporting (writing) of basic statistical methods and results. The results suggest a need for education of patient safety investigators to include statistical writing.

Examination of published articles with respect to statistical errors in veterinary sciences

Abstract The aim of this present work was to examine statistical errors in published veterinary science articles. A total of 204 published articles (SCI or SCI-Exp) were used in this study. The articles were chosen from among those indexed in PubMed database between the years 2010 and 2014, inclusive. A total of 199 articles had at least one statistical error. The most frequently encountered statistical error among the articles published in journals indexed in SCI and in SCI-E was “errors in summarizing data”. No statistical error was found in 2.45% (n=5) of 204 (SCI: 0.98% (1/102), SCI-E: 3.92% (4/102)) articles. To reduce and prevent statistical errors in publications, the researchers must have a basic knowledge of statistics and during the study process they must consult field experts. While reviewing, the reviewers have to redirect the publications to statistical editors when needed and most importantly during the process of editing, the editors have to direct the publications to a statistics reviewer.