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Ruben PA van Eijk,1 Marinus JC Eijkemans,2 Dimitris Rizopoulos,3 Leonard H van den Berg,4,* Stavros Nikolakopoulos5,* 1Department of Neurology, University Medical Center Utrecht, Utrecht, the Netherlands; 2Department of Biostatistics, University Medical Center Utrecht, Utrecht, the Netherlands; 3Department of Biostatistics, Erasmus University Medical Center, Rotterdam, the Netherlands; 4Department of Neurology, University Medical Center Utrecht, Utrecht, the Netherlands; 5Department of Biostatistics, University Medical Center Utrecht, Utrecht, the Netherlands *These authors contributed equally to this work Objective: Amyotrophic lateral sclerosis (ALS) clinical trials based on single end points only partially capture the full treatment effect when both function and mortality are affected, and may falsely dismiss efficacious drugs as futile. We aimed to investigate the statistical properties of several strategies for the simultaneous analysis of function and mortality in ALS clinical trials. Methods: Based on the Pooled Resource Open-Access ALS Clinical Trials (PRO-ACT) database, we simulated longitudinal patterns of functional decline, defined by the revised amyotrophic lateral sclerosis functional rating scale (ALSFRS-R) and conditional survival time. Different treatment scenarios with varying effect sizes were simulated with follow-up ranging from 12 to 18 months. We considered the following analytical strategies: 1) Cox model; 2) linear mixed effects (LME) model; 3) omnibus test based on Cox and LME models; 4) composite time-to-6-point decrease or death; 5) combined assessment of function and survival (CAFS); and 6) test based on joint modeling framework. For each analytical strategy, we calculated the empirical power and sample size. Results: Both Cox and LME models have increased false-negative rates when treatment exclusively affects either function or survival. The joint model has superior power compared to other strategies. The composite end point increases false-negative rates among all treatment scenarios. To detect a 15% reduction in ALSFRS-R decline and 34% decline in hazard with 80% power after 18 months, the Cox model requires 524 patients, the LME model 794 patients, the omnibus test 526 patients, the composite end point 1,274 patients, the CAFS 576 patients and the joint model 464 patients. Conclusion: Joint models have superior statistical power to analyze simultaneous effects on survival and function and may circumvent pitfalls encountered by other end points. Optimizing trial end points is essential, as selecting suboptimal outcomes may disguise important treatment clues. Keywords: joint models, CAFS, clinical trials, amyotrophic lateral sclerosis

BACKGROUND Chronic endometritis is associated with abnormal uterine bleeding, recurrent abortion and infertility. It is a subtle condition, and therefore is difficult to diagnose. The diagnosis is ultimately based on the presence of plasma cells in the endometrial stroma on histopathological examination. Literature on the reproducibility of the diagnosis of chronic endometritis is lacking. Therefore, the aim of the current study was to assess the interobserver agreement of two pathologists in diagnosing chronic endometritis in asymptomatic, infertile patients. METHODS In the context of a randomized controlled trial, an endometrial biopsy was taken during a screening hysteroscopy prior to IVF. All endometrial samples were independently examined by two pathologist. The slides diagnosed with chronic endometritis were replenished with a random sample of the remaining slides up to a total of 100, then exchanged between the two pathologists and reassessed. RESULTS Of the 678 patients who underwent hysteroscopy, 19 patients were diagnosed with at least possible chronic endometritis (2.8%). Perfect agreement between the pathologists, before and after inclusion of 13 slides with additional immunohistochemistry staining, was found in 88 and 86% of reviews, respectively. The interobserver agreement was substantial, with kappa-values of 0.55 and 0.66, respectively. CONCLUSIONS The interobserver agreement in diagnosing chronic endometritis in asymptomatic infertile patients was found to be substantial. Although the diagnostic reliability is sufficient with the methods in the present study, the low prevalence and unknown clinical significance of endometritis warrants further study. [ABSTRACT FROM AUTHOR]

BACKGROUND:: Routine predictions made by surgeons or historical mean durations have only limited capacity to predict operating room (OR) time. The authors aimed to devise a prediction model using the surgeon's estimate and characteristics of the surgical team, the operation, and the patient. METHODS:: Seventeen thousand four hundred twelve consecutive, elective operations from the general surgical department in an academic hospital were analyzed. The outcome was OR time, and the potential predictive factors were surgeon's estimate, number of planned procedures, number and experience of surgeons and anesthesiologists, patient's age and sex, number of previous hospital admissions, body mass index, and eight cardiovascular risk factors. Linear mixed modeling on the logarithm of the total OR time was performed. RESULTS:: Characteristics of the operation and the team had the largest predictive performance, whereas patient characteristics had a modest but distinct effect on OR time: operations were shorter for patients older than 60 yr, and higher body mass index was associated with longer OR times. The surgeon's estimate had an independent and substantial contribution to the prediction, and the final model explained 27% of the residual variation in log (OR time). Using the prediction model instead of the surgeon's prediction based on historical averages would reduce shorter-than-predicted and longer-than-predicted OR time by 2.8 and 6.6 min per case (a relative reduction of 12 and 25%, respectively), assessed on independent validation data. CONCLUSIONS:: Detailed information on the operative session, the team, and the patient substantially improves the prediction of OR times, but the surgeon's estimate remains important. The prediction model may be used in OR scheduling. [ABSTRACT FROM AUTHOR]

We aimed to separate the influence of radiologist experience from that of CT quality in the evaluation of CT examinations of patients with esophageal or gastric cardia cancer. Two radiologists from referral centers ('expert radiologists') and six radiologists from regional non-referral centers ('non-expert radiologists') performed 240 evaluations of 72 CT examinations of patients diagnosed with esophageal or gastric cardia cancer between 1994 and 2003. We used conditional logistic regression analysis to calculate odds ratios (OR) for the likelihood of a correct diagnosis. Expert radiologists made a correct diagnosis of the presence or absence of distant metastases according to the gold standard almost three times more frequently (OR 2.9; 95% CI 1.4-6.3) than non-expert radiologists. For the subgroup of CT examinations showing distant metastases, a statistically significant correlation (OR 3.5; 95% CI 1.4-9.1) was found between CT quality as judged by the radiologists and a correct diagnosis. Both radiologist experience and quality of the CT examination play a role in the detection of distant metastases in esophageal or gastric cardia cancer patients. Therefore, we suggest that staging procedures for esophageal and gastric cardia cancer should preferably be performed in centers with technically advanced equipment and experienced radiologists. [ABSTRACT FROM AUTHOR]

Background: Questionnaires are the current hallmark for quantifying social functioning in human clinical research. In this study, we compared self- and proxy-rated (caregiver and researcher) assessments of social functioning in Schizophrenia (SZ) and Alzheimer's disease (AD) patients and evaluated if the discrepancy between the two assessments is mediated by disease-related factors such as symptom severity., Methods: We selected five items from the WHO Disability Assessment Schedule 2.0 (WHODAS) to assess social functioning in 53 AD and 61 SZ patients. Caregiver- and researcher-rated assessments of social functioning were used to calculate the discrepancies between self-rated and proxy-rated assessments. Furthermore, we used the number of communication events via smartphones to compare the questionnaire outcomes with an objective measure of social behaviour., Results: WHODAS results revealed that both AD (p < 0.001) and SZ (p < 0.004) patients significantly overestimate their social functioning relative to the assessment of their caregivers and/or researchers. This overestimation is mediated by the severity of cognitive impairments (MMSE; p = 0.019) in AD, and negative symptoms (PANSS; p = 0.028) in SZ. Subsequently, we showed that the proxy scores correlated more strongly with the smartphone communication events of the patient when compared to the patient-rated questionnaire scores (self; p = 0.076, caregiver; p < 0.001, researcher-rated; p = 0.046)., Conclusion: Here we show that the observed overestimation of WHODAS social functioning scores in AD and SZ patients is partly driven by disease-related biases such as cognitive impairments and negative symptoms, respectively. Therefore, we postulate the development and implementation of objective measures of social functioning that may be less susceptible to such biases., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Study Question: Can we replicate the finding that the benefit of IUI-ovarian stimulation (IUI-OS) compared to expectant management for couples with unexplained subfertility depends on the prognosis of natural conception?, Summary Answer: The estimated benefit of IUI-OS did not depend on the prognosis of natural conception but did depend on when treatment was started after diagnosis, with starting IUI-OS later yielding a larger absolute and relative benefit of treatment., What Is Known Already: IUI-OS is often the first-line treatment for couples with unexplained subfertility. Two randomized controlled trials (RCTs) compared IUI-OS to expectant management using different thresholds for the prognosis of natural conception as inclusion criteria and found different results. In a previous study (a Dutch national cohort), it was found that the benefit of IUI-OS compared to expectant management seemed dependent on the prognosis of natural conception, but this finding warrants replication., Study Design Size Duration: We conducted a secondary analysis of the H2Oil study (n = 1119), a multicentre RCT that evaluated the effect of oil-based contrast versus water-based contrast during hysterosalpingography (HSG). Couples were randomized before HSG and followed up for 3-5 years. We selected couples with unexplained subfertility who received HSG and had follow-up or pregnancy data available. Follow-up was censored at the start of IVF, after the last IUI cycle or at last contact and was truncated at a maximum of 18 months after the fertility workup., Participants/materials Setting Methods: The endpoint was time to conception leading to an ongoing pregnancy. We used the sequential Cox approach comparing in each month the ongoing pregnancy rates over the next 6 months of couples who started IUI-OS to couples who did not. We calculated the prognosis of natural conception for individual couples, updated this over consecutive failed cycles and evaluated whether prognosis modified the effect of starting IUI-OS. We corrected for known predictors of conception using inverse probability weighting., Main Results and the Role of Chance: Data from 975 couples were available. There were 587 couples who received at least one IUI-OS cycle within 18 months after HSG of whom 221 conceived leading to an ongoing pregnancy (rate: 0.74 per couple per year over a median follow-up for IUI of 5 months). The median period between HSG and starting IUI-OS was 4 months. Out of 388 untreated couples, 299 conceived naturally (rate: 0.56 per couple per year over a median follow-up of 4 months). After creating our mimicked trial datasets, starting IUI-OS was associated with a higher chance of ongoing pregnancy by a pooled, overall hazard ratio of 1.50 (95% CI: 1.19-1.89) compared to expectant management. We did not find strong evidence that the effect of treatment was modified by a couple's prognosis of achieving natural conception (Akaike's Information Criterion (AIC) decreased by 1 point). The effect of treatment was dependent on when couples started IUI-OS (AIC decreased by more than 2 points). The patterns of estimated absolute chances over time for couples with increasingly better prognoses were different from the previous study but the finding that starting later yields a larger benefit of treatment was similar. We found IUI-OS increased the absolute chance of pregnancy by at least 5% compared to expectant management. The absolute chance of pregnancy after IUI-OS seems less variable between couples and starting times of treatment than the absolute chance after expectant management., Limitations Reasons for Caution: This is a secondary analysis, as the H2Oil trial was not designed with this research question in mind. Owing to sample size restrictions, it remained difficult to distinguish between the ranges of prognoses in which true benefit was found., Wider Implications of the Findings: We replicated the finding that starting IUI-OS later after diagnosis yields a larger absolute and relative benefit of treatment. We did not replicate the dependency of the effect of IUI-OS on the prognosis of natural conception and could not identify clear thresholds for the prognosis of natural conception when IUI-OS was and/or was not effective. Because many of these couples still have good chances of natural conception at the time of diagnosis, we suggest clinicians should advise couples to delay the start of IUI-OS for several months to avoid unnecessary treatment., Study Funding/competing Interests: The H2Oil study (NTR 3270) was an investigator-initiated study that was funded by the two academic institutions (AMC and VUmc) of the Amsterdam UMC. The follow-up study (NTR 6577) was also an investigator-initiated study with funding by Guerbet, France. The funders had no role in study design, collection, analysis and interpretation of the data. B.W.M. is supported by an Investigator grant (GNT1176437) from the Australian National Health and Medical Research Council (NHMRC). K.D. reports receiving travel and speaker fees from Guerbet. B.W.M. reports consultancy for ObsEva, Merck, Merck KGaA, iGenomix and Guerbet. V.M. reports receiving travel- and speaker fees as well as research grants from Guerbet., (© The Author(s) 2020. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Study Question: Over a time period of 3 years, which order of expectant management (EM), IUI with ovarian stimulation (IUI-OS) and IVF is the most cost-effective for couples with unexplained subfertility with the female age below 38 years?, Summary Answer: If a live birth is considered worth €32 000 or less, 2 years of EM followed by IVF was the most cost-effective, whereas above €32 000 this was 1 year of EM, 1 year of IUI-OS and then 1 year of IVF., What Is Known Already: IUI-OS and IVF are commonly used fertility treatments for unexplained subfertility although many couples can conceive naturally, as no identifiable barrier to conception could be found by definition. Few countries have guidelines on when to proceed with medically assisted reproduction (MAR), mostly based on the expected probability of live birth after treatment, but there is a lack of evidence to support the strategies proposed by these guidelines. The increased uptake of IUI-OS and IVF over the past decades and costs related to reimbursement of these treatments are pressing concerns to health service providers. For MAR to remain affordable, sustainable and a responsible use of public funds, guidance is needed on the cost-effectiveness of treatment strategies for unexplained subfertility, including EM., Study Design, Size, Duration: We developed a decision analytic Markov model that follows couples with unexplained subfertility of which the woman is under 38 years of age for a time period of 3 years from completion of the fertility workup onwards. We divided the time axis of 3 years into three separate periods, each comprising 1 year. The model was based on contemporary evidence, most notably the dynamic prediction model for natural conception, which was combined with MAR treatment effects from a network meta-analysis on randomized controlled trials. We changed the order of options for managing unexplained subfertility for the 1 year periods to yield five different treatment policies in total: IVF-EM-EM (immediate IVF), EM-IVF-EM (delayed IVF), EM-EM-IVF (postponed IVF), IUIOS-IVF-EM (immediate IUI-OS) and EM-IUIOS-IVF (delayed IUI-OS)., Participants/materials, Setting, Methods: The main outcomes per policy over the 3-year period were the probability of live birth, the average treatment and delivery costs, the probability of multiple pregnancy, the incremental cost-effectiveness ratio (ICER) and finally, which policy yields the highest net benefit in which costs for a policy were deducted from the health effects, i.e. live births gained. We chose the Dutch societal perspective, but the model can be easily modified for other locations or other perspectives. The probability of live birth after EM was taken from the dynamic prediction model for natural conception and updated for Years 2 and 3. The relative effects of IUI-OS and IVF in terms of odds ratios, taken from the network meta-analysis, were applied to the probability of live birth after EM. We applied standard discounting procedures for economic analyses for Years 2 and 3. The uncertainty around effectiveness, costs and other parameters was assessed by probabilistic sensitivity analysis in which we drew values from distributions and repeated this procedure 20 000 times. In addition, we changed model assumptions to assess their influence on our results., Main Results and the Role of Chance: From IVF-EM-EM to EM-IUIOS-IVF, the probability of live birth varied from approximately 54-64% and the average costs from approximately €4000 to €9000. The policies IVF-EM-EM and EM-IVF-EM were dominated by EM-EM-IVF as the latter yielded a higher cumulative probability of live birth at a lower cost. The policy IUIOS-IVF-EM was dominated by EM-IUIOS-IVF as the latter yielded a higher cumulative probability of live birth at a lower cost. After removal of policies that were dominated, the ICER for EM-IUIOS-IVF was approximately €31 000 compared to EM-EM-IVF. The range of ICER values between the lowest 25% and highest 75% of simulation replications was broad. The net benefit curve showed that when we assume a live birth to be worth approximately €20 000 or less, the policy EM-EM-IVF had the highest probability to achieve the highest net benefit. Between €20 000 and €50 000 monetary value per live birth, it was uncertain whether EM-EM-IVF was better than EM-IUIOS-IVF, with the turning point of €32 000. When we assume a monetary value per live birth over €50 000, the policy with the highest probability to achieve the highest net benefit was EM-IUIOS-IVF. Results for subgroups with different baseline prognoses showed the same policies dominated and the same two policies that were the most likely to achieve the highest net benefit but at different threshold values for the assumed monetary value per live birth., Limitations, Reasons for Caution: Our model focused on population level and was thus based on average costs for the average number of cycles conducted. We also based the model on a number of key assumptions. We changed model assumptions to assess the influence of these assumptions on our results. The change in relative effectiveness of IVF over time was found to be highly influential on results and their interpretation., Wider Implications of the Findings: EM-EM-IVF and EM-IUIOS-IVF followed by IVF were the most cost-effective policies. The choice depends on the monetary value assigned to a live birth. The results of our study can be used in discussions between clinicians, couples and policy makers to decide on a sustainable treatment protocol based on the probability of live birth, the costs and the limitations of MAR treatment., Study Funding/competing Interest(s): This work was supported by the ZonMw Doelmatigheidsonderzoek (80-85200-98-91072). The funder had no role in the design, conduct or reporting of this work. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck KGaA and Guerbet and travel and research support from ObsEva, Merck and Guerbet., Trial Registration Number: N/A., (© The Author(s) 2020. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

We conducted a simulation study to compare two methods that have been recently used in clinical literature for the dynamic prediction of time to pregnancy. The first is landmarking, a semi-parametric method where predictions are updated as time progresses using the patient subset still at risk at that time point. The second is the beta-geometric model that updates predictions over time from a parametric model estimated on all data and is specific to applications with a discrete time to event outcome. The beta-geometric model introduces unobserved heterogeneity by modelling the chance of an event per discrete time unit according to a beta distribution. Due to selection of patients with lower chances as time progresses, the predicted probability of an event decreases over time. Both methods were recently used to develop models predicting the chance to conceive naturally. The advantages, disadvantages and accuracy of these two methods are unknown. We simulated time-to-pregnancy data according to different scenarios. We then compared the two methods by the following out-of-sample metrics: bias and root mean squared error in the average prediction, root mean squared error in individual predictions, Brier score and c statistic. We consider different scenarios including data-generating mechanisms for which the models are misspecified. We applied the two methods on a clinical dataset comprising 4999 couples. Finally, we discuss the pros and cons of the two methods based on our results and present recommendations for use of either of the methods in different settings and (effective) sample sizes., (© 2019 The Authors. Biometrical Journal Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Clinical management for unexplained infertility includes expectant management as well as active treatments, including ovarian stimulation (OS), intrauterine insemination (IUI), OS-IUI,  and in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI).Existing systematic reviews have conducted head-to-head comparisons of these interventions using pairwise meta-analyses. As this approach allows only the comparison of two interventions at a time and is contingent on the availability of appropriate primary evaluative studies, it is difficult to identify the best intervention in terms of effectiveness and safety. Network meta-analysis compares multiple treatments simultaneously by using both direct and indirect evidence and provides a hierarchy of these treatments, which can potentially better inform clinical decision-making., Objectives: To evaluate the effectiveness and safety of different approaches to clinical management (expectant management, OS, IUI, OS-IUI, and IVF/ICSI) in couples with unexplained infertility., Search Methods: We performed a systematic review and network meta-analysis of relevant randomised controlled trials (RCTs). We searched electronic databases including the Cochrane Gynaecology and Fertility Group Specialised Register of Controlled Trials, the Cochrane Central Register of Studies Online, MEDLINE, Embase, PsycINFO and CINAHL, up to 6 September 2018, as well as reference lists, to identify eligible studies. We also searched trial registers for ongoing trials., Selection Criteria: We included RCTs comparing at least two of the following clinical management options in couples with unexplained infertility: expectant management, OS, IUI, OS-IUI, and IVF (or combined with ICSI)., Data Collection and Analysis: Two review authors independently screened titles and abstracts identified by the search strategy. We obtained the full texts of potentially eligible studies to assess eligibility and extracted data using standardised forms. The primary effectiveness outcome was a composite of cumulative live birth or ongoing pregnancy, and the primary safety outcome was multiple pregnancy. We performed a network meta-analysis within a random-effects multi-variate meta-analysis model. We presented treatment effects by using odds ratios (ORs) and 95% confidence intervals (CIs). For the network meta-analysis, we used Confidence in Network Meta-analysis (CINeMA) to evaluate the overall certainty of evidence., Main Results: We included 27 RCTs (4349 couples) in this systematic review and 24 RCTs (3983 couples) in a subsequent network meta-analysis. Overall, the certainty of evidence was low to moderate: the main limitations were imprecision and/or heterogeneity.Ten RCTs including 2725 couples reported on live birth. Evidence of differences between OS, IUI, OS-IUI, or IVF/ICSI versus expectant management was insufficient (OR 1.01, 95% CI 0.51 to 1.98; low-certainty evidence; OR 1.21, 95% CI 0.61 to 2.43; low-certainty evidence; OR 1.61, 95% CI 0.88 to 2.94; low-certainty evidence; OR 1.88, 95 CI 0.81 to 4.38; low-certainty evidence). This suggests that if the chance of live birth following expectant management is assumed to be 17%, the chance following OS, IUI, OS-IUI, and IVF would be 9% to 28%, 11% to 33%, 15% to 37%, and 14% to 47%, respectively. When only including couples with poor prognosis of natural conception (3 trials, 725 couples) we found OS-IUI and IVF/ICSI increased live birth rate compared to expectant management (OR 4.48, 95% CI 2.00 to 10.1; moderate-certainty evidence; OR 4.99, 95 CI 2.07 to 12.04; moderate-certainty evidence), while there was insufficient evidence of a difference between IVF/ICSI and OS-IUI (OR 1.11, 95% CI 0.78 to 1.60; low-certainty evidence).Eleven RCTs including 2564 couples reported on multiple pregnancy. Compared to expectant management/IUI, OS (OR 3.07, 95% CI 1.00 to 9.41; low-certainty evidence) and OS-IUI (OR 3.34 95% CI 1.09 to 10.29; moderate-certainty evidence) increased the odds of multiple pregnancy, and there was insufficient evidence of a difference between IVF/ICSI and expectant management/IUI (OR 2.66, 95% CI 0.68 to 10.43; low-certainty evidence). These findings suggest that if the chance of multiple pregnancy following expectant management or IUI is assumed to be 0.6%, the chance following OS, OS-IUI, and IVF/ICSI would be 0.6% to 5.0%, 0.6% to 5.4%, and 0.4% to 5.5%, respectively.Trial results show insufficient evidence of a difference between IVF/ICSI and OS-IUI for moderate/severe ovarian hyperstimulation syndrome (OHSS) (OR 2.50, 95% CI 0.92 to 6.76; 5 studies; 985 women; moderate-certainty evidence). This suggests that if the chance of moderate/severe OHSS following OS-IUI is assumed to be 1.1%, the chance following IVF/ICSI would be between 1.0% and 7.2%., Authors' Conclusions: There is insufficient evidence of differences in live birth between expectant management and the other four interventions (OS, IUI, OS-IUI, and IVF/ICSI). Compared to expectant management/IUI, OS may increase the odds of multiple pregnancy, and OS-IUI probably increases the odds of multiple pregnancy. Evidence on differences between IVF/ICSI and expectant management for multiple pregnancy is insufficient, as is evidence of a difference for moderate or severe OHSS between IVF/ICSI and OS-IUI.

Binary logistic regression is one of the most frequently applied statistical approaches for developing clinical prediction models. Developers of such models often rely on an Events Per Variable criterion (EPV), notably EPV ≥10, to determine the minimal sample size required and the maximum number of candidate predictors that can be examined. We present an extensive simulation study in which we studied the influence of EPV, events fraction, number of candidate predictors, the correlations and distributions of candidate predictor variables, area under the ROC curve, and predictor effects on out-of-sample predictive performance of prediction models. The out-of-sample performance (calibration, discrimination and probability prediction error) of developed prediction models was studied before and after regression shrinkage and variable selection. The results indicate that EPV does not have a strong relation with metrics of predictive performance, and is not an appropriate criterion for (binary) prediction model development studies. We show that out-of-sample predictive performance can better be approximated by considering the number of predictors, the total sample size and the events fraction. We propose that the development of new sample size criteria for prediction models should be based on these three parameters, and provide suggestions for improving sample size determination.

Study Question: Which couples with unexplained subfertility can expect increased chances of ongoing pregnancy with IVF compared to expectant management?, Summary Answer: For couples in which the woman is under 40 years of age, IVF is associated with higher chances of conception than expectant management., What Is Known Already: The clinical indications for IVF have expanded over time from bilateral tubal blockage to include unexplained subfertility in which there is no identifiable barrier to conception. Yet, there is little evidence from randomized controlled trials that IVF is effective in these couples., Study Design, Size, Duration: We compared outcomes in British couples with unexplained subfertility undergoing IVF (n = 40 921) from registry data to couples with the same type of subfertility on expectant management. Those couples on expectant management (defined as no intervention aside from the advice to have intercourse) comprised a prospective nation-wide Dutch cohort (n = 4875) and a retrospective regional cohort from Aberdeen, Scotland (n = 975). We excluded couples who had tried for <1 year to conceive and also those with anovulation, uni- or bilateral tubal occlusion, mild or severe endometriosis or male subfertility i.e. impaired semen quality according to World Health Organization criteria., Participants/materials, Setting, Methods: We matched couples who received IVF and couples on expectant management based on their characteristics to control for confounding. We fitted a Cox proportional hazards model including patient characteristics, IVF treatment and their interactions to estimate the individualized chance of conception over 1 year-either following IVF or expectant management for all combinations of patient characteristics. The endpoint was conception leading to ongoing pregnancy, defined as a foetus reaching a gestational age of at least 12 weeks., Main Results and the Role of Chance: The adjusted 1-year chance of conception was 47.9% (95% CI: 45.0-50.9) after IVF and 26.1% (95% CI: 24.2-28.0) after expectant management. The absolute difference in the average adjusted 1-year chances of conception was 21.8% (95%CI: 18.3-25.3) in favour of IVF. The effectiveness of IVF was influenced by female age, duration of subfertility and previous pregnancy. IVF was effective in women under 40 years, but the 1-year chance of an IVF conception declined sharply in women over 34 years. In contrast, in woman over 40 years of age, IVF was less effective, with an absolute difference in chance compared to expectant management of 10% or lower. Regardless of female age, IVF was also less effective in couples with a short period of secondary subfertility (1 year) who had chances of natural conception of 30% or above., Limitations, Reasons for Caution: The 1-year chances of conception were based on three cohorts with different sampling mechanisms. Despite adjustment for the three most important prognostic patient characteristics, namely female age, duration of subfertility and primary or secondary subfertility, our estimates might not be free from residual confounding., Wider Implications of the Findings: IVF should be used selectively based on judgements on gain compared to continuing expectant management for a given couple. Our results can be used by clinicians to counsel couples with unexplained subfertility, to inform their expectations and facilitate evidence-based, shared decision making., Study Funding/competing Interest(s): This work was supported by Tenovus Scotland [grant G17.04]. Travel for RvE was supported by the Amsterdam Reproduction & Development Research Group [grant V.000296]. SB reports acting as editor-in-chief of HROpen. Other authors have no conflicts., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Study Question: Can we develop a prediction model that can estimate the chances of conception leading to live birth with and without treatment at different points in time in couples with unexplained subfertility?, Summary Answer: Yes, a dynamic model was developed that predicted the probability of conceiving under expectant management and following active treatments (in vitro fertilisation (IVF), intrauterine insemination with ovarian stimulation (IUI + SO), clomiphene) at different points in time since diagnosis., What Is Known Already: Couples with no identified cause for their subfertility continue to have a realistic chance of conceiving naturally, which makes it difficult for clinicians to decide when to intervene. Previous fertility prediction models have attempted to address this by separately estimating either the chances of natural conception or the chances of conception following certain treatments. These models only make predictions at a single point in time and are therefore inadequate for informing continued decision-making at subsequent consultations., Study Design, Size, Duration: A population-based study of 1316 couples with unexplained subfertility attending a regional clinic between 1998 and 2011., Participants/materials, Setting, Methods: A dynamic prediction model was developed that estimates the chances of conception within 6 months from the point when a diagnosis of unexplained subfertility was made. These predictions were recomputed each month to provide a dynamic assessment of the individualised chances of conception while taking account of treatment status in each month. Conception must have led to live birth and treatments included clomiphene, IUI + SO, and IVF. Predictions for natural conception were externally validated using a prospective cohort from The Netherlands., Main Results and the Role of Chance: A total of 554 (42%) couples started fertility treatment within 2 years of their first fertility consultation. The natural conception leading to live birth rate was 0.24 natural conceptions per couple per year. Active treatment had a higher chance of conception compared to those who remained under expectant management. This association ranged from weak with clomiphene to strong with IVF [clomiphene, hazard ratio (HR) = 1.42 (95% confidence interval, 1.05 to 1.91); IUI + SO, HR = 2.90 (2.06 to 4.08); IVF, HR = 5.09 (4.04 to 6.40)]. Female age and duration of subfertility were significant predictors, without clear interaction with the relative effect of treatment., Limitations, Reasons for Caution: We were unable to adjust for other potentially important predictors, e.g. measures of ovarian reserve, which were not available in the linked Grampian dataset that may have made predictions more specific. This study was conducted using single centre data meaning that it may not be generalizable to other centres. However, the model performed as well as previous models in reproductive medicine when externally validated using the Dutch cohort., Wider Implications of the Findings: For the first time, it is possible to estimate the chances of conception following expectant management and different fertility treatments over time in couples with unexplained subfertility. This information will help inform couples and their clinicians of their likely chances of success, which may help manage expectations, not only at diagnostic workup completion but also throughout their fertility journey., Study Funding/competing Interest(s): This work was supported by a Chief Scientist Office postdoctoral training fellowship in health services research and health of the public research (ref PDF/12/06). B.W.M. is supported by an NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck, and Guerbet. None of the other authors declare any conflicts of interest., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Study Question: Does starting IUI with ovarian stimulation (IUI-OS) within 1.5 years after completion of the fertility workup increase ongoing pregnancy rates compared to expectant management in couples with unexplained subfertility?, Summary Answer: IUI-OS is associated with higher chances of ongoing pregnancy compared to expectant management in unexplained subfertile couples, specifically those with poor prognoses of natural conception, i.e. <15% over 6 months or <25% over 1 year., What Is Known Already: IUI-OS is often the first-line treatment for couples with unexplained subfertility. Two randomized controlled trials compared IUI-OS to expectant management using different thresholds for the prognosis of natural conception as inclusion criteria and found conflicting results. A cohort of couples with unexplained subfertility exposed to expectant management and IUI-OS offers an opportunity to determine the chances of conception after both strategies and to evaluate whether the effect of IUI-OS depends on a couple's prognosis of natural conception., Study Design, Size, Duration: A prospective cohort study on couples with unexplained or mild male subfertility who could start IUI-OS at any point after completion of the fertility workup, recruited in seven Dutch centres between January 2002 and February 2004. Decisions regarding treatment were subject to local protocols, the judgement of the clinician and the wishes of the couple. Couples with bilateral tubal occlusion, anovulation or a total motile sperm count <1 × 106 were excluded. Follow up was censored at the start of IVF, after the last IUI cycle or at last contact and truncated at a maximum of 1.5 years after the fertility workup., Participants/materials, Setting, Methods: The endpoint was time to conception leading to an ongoing pregnancy. We used the sequential Cox approach comparing in each month ongoing pregnancy rates over the next 6 months of couples who started IUI-OS to couples who did not. We calculated the prognosis of natural conception for individual couples, updated this over consecutive failed cycles and evaluated whether prognosis modified the effect of starting IUI-OS. We corrected for known predictors of conception using inverse probability weighting., Main Results and the Role of Chance: Data from 1896 couples were available. There were 800 couples whom had at least one IUI-OS cycle within 1.5 years post fertility workup of whom 142 couples conceived (rate: 0.50 per couple per year, median follow up 4 months). The median period between fertility workup completion and starting IUI-OS was 6.5 months. Out of 1096 untreated couples, 386 conceived naturally (rate: 0.31 per couple per year, median follow up 7 months). Starting IUI-OS was associated with a higher chance of ongoing pregnancy by a pooled, overall hazard ratio of 1.96 (95% CI: 1.47-2.62) compared to expectant management. The effect of treatment was modified by a couple's prognosis of achieving natural conception (P = 0.01), with poorer prognoses or additional failed natural cycles being associated with a stronger effect of treatment. The predicted 6-month ongoing pregnancy rate for a couple with a prognosis of 25% at completion of the fertility workup over the next six cycles (~40% over 1 year) was 25% (95% CI: 21-28%) for expectant management and 24% (95% CI: 9-36%) when starting IUI-OS directly. For a couple with a prognosis of 15% (25% over 1 year), these predicted rates were 17% (95% CI: 15-19%) for expectant management and 24% (95% CI: 15-32%) for starting IUI-OS., Limitations, Reasons for Caution: The effect estimates are based on a prospective cohort followed up for 1.5 years after completion of the fertility workup. Although we balanced the known predictors of conception between treated and untreated couples using inverse probability weighting, observational data may be subject to residual confounding. The results need to be confirmed in external datasets., Wider Implications of the Findings: These results explain the discrepancies between previous trials that compared IUI-OS to expectant management, but further studies are required to establish the threshold at which IUI-OS is (cost-)effective., Study Funding/competing Interest(s): This study was facilitated by (Grant 945/12/002) from ZonMW, The Netherlands Organization for Health Research and Development, The Hague, The Netherlands. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for ObsEva, Merck and Guerbet. S.B. reports acting as Editor-in-Chief of HROpen. The other authors have no conflicts of interest.

Study Question: How well does a previously developed dynamic prediction model perform in an external, geographical validation in terms of predicting the chances of natural conception at various points in time?, Summary Answer: The dynamic prediction model performs well in an external validation on a Scottish cohort., What Is Known Already: Prediction models provide information that can aid evidence-based management of unexplained subfertile couples. We developed a dynamic prediction model for natural conception (van Eekelen model) that is able to update predictions of natural conception when couples return to their clinician after a period of unsuccessful expectant management. It is not known how well this model performs in an external population., Study Design, Size, Duration: A record-linked registry study including the long-term follow-up of all couples who were considered unexplained subfertile following a fertility workup at a Scottish fertility clinic between 1998 and 2011. Couples with anovulation, uni/bilateral tubal occlusion, mild/severe endometriosis or impaired semen quality according to World Health Organization criteria were excluded., Participants/materials, Setting, Methods: The endpoint was time to natural conception, leading to an ongoing pregnancy (defined as reaching a gestational age of at least 12 weeks). Follow-up was censored at the start of treatment, at the change of partner or at the end of study (31 March 2012). The performance of the van Eekelen model was evaluated in terms of calibration and discrimination at various points in time. Additionally, we assessed the clinical utility of the model in terms of the range of the calculated predictions., Main Results and the Role of Chance: Of a total of 1203 couples with a median follow-up of 1 year and 3 months after the fertility workup, 398 (33%) couples conceived naturally leading to an ongoing pregnancy. Using the dynamic prediction model, the mean probability of natural conception over the course of the first year after the fertility workup was estimated at 25% (observed: 23%). After 0.5, 1 and 1.5 years of expectant management after the completion of the fertility workup, the average probability of conceiving naturally over the next year was estimated at 18% (observed: 15%), 14% (observed: 14%) and 12% (observed: 12%). Calibration plots showed good agreement between predicted chances and the observed fraction of ongoing pregnancy within risk groups. Discrimination was moderate with c statistics similar to those in the internal validation, ranging from 0.60 to 0.64. The range of predicted chances was sufficiently wide to distinguish between couples having a good and poor prognosis with a minimum of zero at all times and a maximum of 55% over the first year after the workup, which decreased to maxima of 43% after 0.5 years, 34% after 1 year and 29% after 1.5 years after the fertility workup., Limitations, Reasons for Caution: The model slightly overestimated the chances of conception by ~2-3% points on group level in the first-year post-fertility workup and after 0.5 years of expectant management, respectively. This is likely attributable to the fact that the exact dates of completion of the fertility workup for couples were missing and had to be estimated., Wider Implications of the Findings: The van Eekelen model is a valid and robust tool that is ready to use in clinical practice to counsel couples with unexplained subfertility on their individualized chances of natural conception at various points in time, notably when couples return to the clinic after a period of unsuccessful expectant management., Study Funding/competing Interest(s): This work was supported by a Chief Scientist Office postdoctoral training fellowship in health services research and health of the public research (ref PDF/12/06). There are no conflicts of interest.

Aim: To define the predictors of long-term mortality in patients with type 2 diabetes mellitus and recent acute coronary syndrome., Methods and Results: A total of 7226 patients from a randomized trial, testing the effect on cardiovascular outcomes of the dual peroxisome proliferator-activated receptor agonist aleglitazar in patients with type 2 diabetes mellitus and recent acute coronary syndrome (AleCardio trial), were analysed. Median follow-up was 2 years. The independent mortality predictors were defined using Cox regression analysis. The predictive information provided by each variable was calculated as percent of total chi-square of the model. All-cause mortality was 4.0%, with cardiovascular death contributing for 73% of mortality. The mortality prediction model included N-terminal proB-type natriuretic peptide (adjusted hazard ratio = 1.68; 95% confidence interval = 1.51-1.88; 27% of prediction), lack of coronary revascularization (hazard ratio = 2.28; 95% confidence interval = 1.77-2.93; 18% of prediction), age (hazard ratio = 1.04; 95% confidence interval = 1.02-1.05; 15% of prediction), heart rate (hazard ratio = 1.02; 95% confidence interval = 1.01-1.03; 10% of prediction), glycated haemoglobin (hazard ratio = 1.11; 95% confidence interval = 1.03-1.19; 8% of prediction), haemoglobin (hazard ratio = 1.01; 95% confidence interval = 1.00-1.02; 8% of prediction), prior coronary artery bypass (hazard ratio = 1.61; 95% confidence interval = 1.11-2.32; 7% of prediction) and prior myocardial infarction (hazard ratio = 1.40; 95% confidence interval = 1.05-1.87; 6% of prediction)., Conclusion: In patients with type 2 diabetes mellitus and recent acute coronary syndrome, mortality prediction is largely dominated by markers of cardiac, rather than metabolic, dysfunction.

Couples in whom the results of an initial fertility workup fail to identify the presence of any obvious barriers to conception are diagnosed with unexplained subfertility. Couples who have tried to conceive for a relatively short time have a good chance of natural conception and thus may not benefit from immediate access to ART. As fertility decreases over time, the main dilemma that clinicians and couples face is when to abandon an expectant approach in favour of active treatment. Several prognostic or predictive models have been used to try to discriminate between couples with high and low chances of conception but have been unable to compare individualized chances of conception associated with ART relative to chances of natural conception at various time points. These models are also unable to recalculate the chances of pregnancy at subsequent time points in those who return after a period of unsuccessful expectant management. In this paper, we discuss currently available models. We conclude that in order to provide accurate, individualized and dynamic fertility prognoses associated with and without treatment at different points in time, we need to develop, validate and update clinical prediction models which are fit for purpose. We suggest several steps to move the field forwards., (© The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Worldwide induction and cesarean delivery rates have increased rapidly, with consequences for subsequent pregnancies. The majority of intrapartum cesarean deliveries are performed for failure to progress, typically in nulliparous women at term. Current uterine registration techniques fail to identify inefficient contractions leading to first-stage labor arrest. An alternative technique, uterine electromyography has been shown to identify inefficient contractions leading to first-stage arrest of labor in nulliparous women with spontaneous onset of labor at term. The objective of this study was to determine whether this finding can be reproduced in induction of labor., Material and Methods: Uterine activity was measured in 141 nulliparous women with singleton term pregnancies and a fetus in cephalic position during induced labor. Electrical activity of the myometrium during contractions was characterized by its power density spectrum., Results: No significant differences were found in contraction characteristics between women with induced labor delivering vaginally with or without oxytocin and women with arrested labor with subsequent cesarean delivery., Conclusion: Uterine electromyography shows no correlation with progression of labor in induced labor, which is in contrast to spontaneous labor., (© 2017 Nordic Federation of Societies of Obstetrics and Gynecology.)

Background: Aggregating gene expression data across experiments via meta-analysis is expected to increase the precision of the effect estimates and to increase the statistical power to detect a certain fold change. This study evaluates the potential benefit of using a meta-analysis approach as a gene selection method prior to predictive modeling in gene expression data., Results: Six raw datasets from different gene expression experiments in acute myeloid leukemia (AML) and 11 different classification methods were used to build classification models to classify samples as either AML or healthy control. First, the classification models were trained on gene expression data from single experiments using conventional supervised variable selection and externally validated with the other five gene expression datasets (referred to as the individual-classification approach). Next, gene selection was performed through meta-analysis on four datasets, and predictive models were trained with the selected genes on the fifth dataset and validated on the sixth dataset. For some datasets, gene selection through meta-analysis helped classification models to achieve higher performance as compared to predictive modeling based on a single dataset; but for others, there was no major improvement. Synthetic datasets were generated from nine simulation scenarios. The effect of sample size, fold change and pairwise correlation between differentially expressed (DE) genes on the difference between MA- and individual-classification model was evaluated. The fold change and pairwise correlation significantly contributed to the difference in performance between the two methods. The gene selection via meta-analysis approach was more effective when it was conducted using a set of data with low fold change and high pairwise correlation on the DE genes., Conclusion: Gene selection through meta-analysis on previously published studies potentially improves the performance of a predictive model on a given gene expression data.

Background: Earlier age at menopause is widely considered to be associated with an increased risk of cardiovascular disease. However, the underlying mechanisms of this relationship remain undetermined. Indications suggest that anti-Müllerian hormone (AMH), an ovarian reserve marker, plays a physiological role outside of the reproductive system. Therefore, we investigated whether longitudinal AMH decline trajectories are associated with an increased risk of cardiovascular disease (CVD) occurrence., Methods: This study included 3108 female participants between 20 and 60 years of age at baseline of the population-based Doetinchem Cohort. Participants completed ≥1 of 5 consecutive quinquennial visits between 1987 and 2010, resulting in a total follow-up time of 20 years. AMH was measured in 8507 stored plasma samples. Information on total CVD, stroke, and coronary heart disease was obtained through a hospital discharge registry linkage. The association of AMH trajectories with CVD was quantified with joint modeling, with adjustment for age, smoking, oral contraceptive use, body mass index, menopausal status, postmenopausal hormone therapy use, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and glucose levels., Results: By the end of follow-up, 8.2% of the women had suffered from CVD, 4.9% had suffered from coronary heart disease, and 2.6% had experienced a stroke. After adjustment, each ng/mL lower log AMH level was associated with a 21% higher risk of CVD (hazard ratio, 1.21; 95% confidence interval, 1.07-1.36) and a 26% higher risk of coronary heart disease (hazard ratio, 1.25; 95% confidence interval, 1.08-1.46). Each additional ng/mL/year decrease of log AMH was associated with a significantly higher risk of CVD (hazard ratio, 1.46; 95% confidence interval, 1.14-1.87) and coronary heart disease (hazard ratio, 1.56; 95% confidence interval, 1.15-2.12). No association between AMH and stroke was found., Conclusions: These results indicate that AMH trajectories in women are independently associated with CVD risk. Therefore, we postulate that the decline of circulating AMH levels may be part of the pathophysiology of the increased cardiovascular risk of earlier menopause. Confirmation of this association and elucidation of its underlying mechanisms are needed to place these results in a clinical perspective., (© 2017 American Heart Association, Inc.)

Study Question: How can we predict chances of natural conception at various time points in couples diagnosed with unexplained subfertility?, Summary Answer: We developed a dynamic prediction model that can make repeated predictions over time for couples with unexplained subfertility that underwent a fertility workup at a fertility clinic., What Is Known Already: The most frequently used prediction model for natural conception (the 'Hunault model') estimates the probability of natural conception only once per couple, that is, after completion of the fertility workup. This model cannot be used for a second or third time for couples who wish to know their renewed chances after a certain period of expectant management., Study Design, Size, Duration: A prospective cohort studying the long-term follow-up of subfertile couples included in 38 centres in the Netherlands between January 2002 and February 2004. Couples with bilateral tubal occlusion, anovulation or a total motile sperm count <1 × 10 6 were excluded., Participants/materials, Setting, Methods: The primary endpoint was time to natural conception, leading to an ongoing pregnancy. Follow-up time was censored at the start of treatment or at the last date of contact. In developing the new dynamic prediction model, we used the same predictors as the Hunault model, i.e. female age, duration of subfertility, female subfertility being primary or secondary, sperm motility and referral status. The performance of the model was evaluated in terms of calibration and discrimination. Additionally, we assessed the utility of the model in terms of the variability of the calculated predictions., Main Results and the Role of Chance: Of the 4999 couples in the cohort, 1053 (21%) women reached a natural conception leading to an ongoing pregnancy within a mean follow-up of 8 months (5th and 95th percentile: 1-21). Our newly developed dynamic prediction model estimated the median probability of conceiving in the first year after the completion of the fertility workup at 27%. For couples not yet pregnant after half a year, after one year and after one and a half years of expectant management, the median probability of conceiving over the next year was estimated at 20, 15 and 13%, respectively. The model performed fair in an internal validation. The prediction ranges were sufficiently broad to aid in counselling couples for at least two years after their fertility workup., Limitations, Reasons for Caution: The dynamic prediction model needs to be validated in an external population., Wider Implications of the Findings: This dynamic prediction model allows reassessment of natural conception chances after various periods of unsuccessful expectant management. This gives valuable information to counsel couples with unexplained subfertility that are seen for a fertility workup., Study Funding/competing Interests: This study was facilitated by grant 945/12/002 from ZonMW, The Netherlands Organization for Health Research and Development, The Hague, The Netherlands. No competing interests., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Although the association between menopause and cardiovascular disease (CVD) risk has been studied extensively, the simultaneous role of chronological aging herein remains underexposed. This study aims to disentangle the relationships of menopausal status and chronological aging with CVD risk factors in the largest study population to date., Methods: In this cross-sectional study, CVD risk factors were compared between women with a different menopausal status within the same yearly age strata. The study population comprised female participants of the baseline visit of the population-based LifeLines Cohort Study. A total of 63,466 women, aged between 18 and 65 years, was included. Of them, 39,379 women were considered to be premenopausal, 8669 were perimenopausal, 14,514 were naturally postmenopausal, and 904 were surgically postmenopausal., Results: Compared to postmenopausal women aged 45 years, average total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) were 0.5 and 0.4 mmol/L higher, respectively, in postmenopausal women aged 50. Systolic and diastolic blood pressure levels were 4 and 1 mmHg higher, respectively. At all ages between 46 and 55 years, and after adjustment for confounders, naturally postmenopausal women had 0.2 to 0.4 mmol/L higher TC and 0.1 to 0.3 mmol/L higher LDL-c levels compared to premenopausal women in the same age range. Systolic blood pressure levels were up to 4 mmHg lower in naturally post- compared to premenopausal women at all ages between 29 and 52 years. Body mass index levels were up to 3.2 kg/m 2 higher in women with surgical menopause compared to all other women between the ages 32 and 52 years. All aforementioned results were statistically significant., Conclusions: Chronological age and menopausal status are both independently associated with CVD risk factors. Based on the comparatively smaller observed differences associated with menopausal status than with chronological aging, the significance of a more unfavorable lipid profile in a later reproductive stage may be less obvious than previously thought.

Objective: To compare the endocrine and cardiometabolic cord blood characteristics of offspring of mothers with polycystic ovary syndrome (PCOS) with those of healthy controls., Design: Cross-sectional case control study., Setting: University medical centers., Patient(s): Offspring from mothers with PCOS (n = 61) and healthy controls (n = 82)., Intervention(s): Cord blood withdrawal from neonates., Main Outcome Measure(s): Cord blood estradiol, androstenedione, dehydroepiandrosterone sulfate (DHEAS), testosterone, sex hormone-binding globulin, free androgen index (FAI), insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, c-reactive protein, adiponectin, and leptin., Result(s): Androstenedione and leptin concentrations were increased in the offspring of women with PCOS compared with the controls: androstenedione median 2.9 (interquartile range [IQR] 2.3-3.9) nmol/L vs. 2.2 [IQR 1.6-2.7] nmol/L; and leptin median 13.6 [IQR 8.3-22.9] μg/L vs. 9.8 [IQR 6.0-16.5] μg/L. After adjusting for maternal and pregnancy-related confounders (such as maternal age, gestational age, birth weight), androstenedione appeared associated with PCOS in both male (relative change 1.36 [1.04; 1.78]) and female offspring (relative change 1.40 [1.08; 1.82]). Similarly, in male offspring the leptin concentrations appeared associated with PCOS after correction for confounders (relative change 1.55 [1.12; 2.14]). After correction for multiple testing, these associations attenuated., Conclusion(s): Observed results suggest that androstenedione concentrations are increased in the cord blood of male and female offspring of women with PCOS, although this requires confirmation. This finding would support the hypothesis that a maternal hyperandrogenic environment during pregnancy in women with PCOS may predispose their offspring to fetal hyperandrogenism. The potential associations between fetal hyperandrogenism and long-term health effects remain to be elucidated., Clinical Trial Registration Number: NCT00821379., (Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: To determine outcome of children born with isolated gastroschisis (no extra-gastrointestinal congenital abnormalities)., Study Design: International cohort study and meta-analysis., Primary Outcome: time to full enteral feeding (TFEF); secondary outcomes: Duration of mechanical ventilation, length of stay (LOS), mortality and differences in outcome between simple and complex gastroschisis (complex; born with bowel atresia, volvulus, perforation or necrosis). To compare the cohort study results with literature three databases were searched. Studies were eligible for inclusion if cases were born in developed countries with isolated gastroschisis after 1990, number of cases >20 and TFEF was reported., Results: The cohort study included 204 liveborn cases of isolated gastroschisis. The TFEF, median duration of ventilation and LOS was, 26days (range 6-515), 2days (range 0-90) and 33days (range 11-515), respectively. Overall mortality was 10.8%. TFEF and LOS were significantly longer (P<0.0001) and mortality was fourfold higher in the complex group. Seventeen studies, amongst the current study, were included for further meta-analysis comprising a total of 1652 patients. Mean TFEF was 35.3±4.4days, length of ventilation was 5.5±2.0days, LOS was 46.4±5.2days and mortality risk was 0.06 [0.04-0.07 95%CI]. Outcome of simple and complex gastroschisis was described in five studies. TFEF, ventilation time, LOS were significant longer and mortality rate was 3.64 [1.95-6.83 95%CI] times higher in complex cases., Conclusions: These results give a good indication of the expected TFEF, ventilation time and LOS and mortality risk in children born with isolated gastroschisis, although ranges remain wide. This study shows the importance of dividing gastroschisis into simple and complex for the prediction of outcome., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Introduction: This systematic review examines whether individualized gonadotropin dosing in in vitro fertilization (IVF) leads to better outcomes with respect to safety, costs, and live birth rates compared with standard dosing., Material and Methods: Electronic databases searched were PubMed, Embase, and Cochrane. The primary outcome was live birth rate. The secondary outcomes included pregnancy rate, costs, and safety. Papers were critically appraised by two reviewers., Results: A total of 7022 articles were retrieved and assessed for eligibility, of which seven randomized controlled trials were selected. All studies used gonadotropin-releasing hormone agonist co-treatment. Clinical and methodological heterogeneity was present, so data could not be pooled for meta-analysis. Only one study, that mainly included women with a good prognosis, revealed an increased chance of ongoing pregnancy in the individualized dosing group compared with standard treatment. With respect to safety, individualized dosing might reduce the occurrence of hyper-response and ovarian hyperstimulation syndrome, without affecting the outcome of pregnancy. In predicted poor responders, higher than standard dosages do not reduce the incidence of poor response. A cost-efficacy analysis was not performed in any of the studies included., Conclusion: It is currently not possible to conclude whether individualized dosing leads to higher pregnancy or live birth rates compared with standard dosing, because evidence from well-designed studies that are adequately powered for one of these outcomes is lacking. So, large well-designed studies that evaluate the impact of individualized dosing on live birth rates are needed to assess whether individualized dosing should become the standard in IVF practice., (© 2016 Nordic Federation of Societies of Obstetrics and Gynecology.)

Background: Ten events per variable (EPV) is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies., Methods: The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth's correction, are compared., Results: The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect ('separation'). We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth's correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation., Conclusions: The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.

Respiratory syncytial virus (RSV) causes infections that range from common cold to severe lower respiratory tract infection requiring high-level medical care. Prediction of the course of disease in individual patients remains challenging at the first visit to the pediatric wards and RSV infections may rapidly progress to severe disease. In this study we investigate whether there exists a genomic signature that can accurately predict the course of RSV. We used early blood microarray transcriptome profiles from 39 hospitalized infants that were followed until recovery and of which the level of disease severity was determined retrospectively. Applying support vector machine learning on age by sex standardized transcriptomic data, an 84 gene signature was identified that discriminated hospitalized infants with eventually less severe RSV infection from infants that suffered from most severe RSV disease. This signature yielded an area under the receiver operating characteristic curve (AUC) of 0.966 using leave-one-out cross-validation on the experimental data and an AUC of 0.858 on an independent validation cohort consisting of 53 infants. A combination of the gene signature with age and sex yielded an AUC of 0.971. Thus, the presented signature may serve as the basis to develop a prognostic test to support clinical management of RSV patients.

Study Question: Do BRCA1/2 mutation carriers have a compromised ovarian reserve compared to proven non-carriers, based on serum anti-Müllerian hormone (AMH) levels?, Summary Answer: BRCA1/2 mutation carriers do not show a lower serum AMH level in comparison to proven non-carriers, after adjustment for potential confounders., What Is Known Already: It has been suggested that the BRCA genes play a role in the process of ovarian reserve depletion, although previous studies have shown inconsistent results regarding the association between serum AMH levels and BRCA mutation status. Hence, it is yet unclear whether BRCA1/2 mutation carriers may indeed be at risk of a reduced reproductive lifespan. STUDY DESIGN, SIZE, DURATION: A multicenter, cross-sectional study was performed between January 2012 and February 2015 in 255 women. We needed to include 120 BRCA1/2 mutation carriers and 120 proven non-carriers to demonstrate a difference in AMH levels of 0.40 µg/l (SD ± 0.12 µg/l, two-sided alpha-error 0.05, power 80%)., Participants/materials, Setting, Method: Healthy women aged 18-45 years who were referred to the Clinical Genetics Department and applied for predictive BRCA1/2 testing because of a familial BRCA1/2 mutation were asked to participate. A cross-sectional assessment was performed by measuring serum AMH levels and filling out a questionnaire. Multivariate linear regression analyses adjusted for age, current smoking and current hormonal contraceptive use were performed on log-transformed serum AMH levels., Main Results and the Role of Chance: Out of 823 potentially eligible women, 421 (51.2%) were willing to participate, and of those, 166 (39%) did not meet our inclusion criteria. Two hundred and fifty-five women were available for analyses; 124 BRCA1/2 mutation carriers and 131 proven non-carriers. The median [range] AMH level in carriers was 1.90 µg/l [0.11-19.00] compared to 1.80 µg/l [0.11-10.00] in non-carriers (P = 0.34). Adjusted linear regression analysis revealed no reduction in AMH level in the carriers (relative change = 0.98 (95%CI, 0.77-1.22); P = 0.76)., Limitations, Reasons for Caution: Participants were relatively young. Power was insufficient to analyze BRCA1 and BRCA2 mutation carriers separately. AMH levels may have been influenced by the use of hormonal contraceptives, though similar proportions of carriers and non-carriers were current users and adjustments were made to correct for potential confounding in our analysis., Wider Implications of the Findings: Limitations of the current analysis and limitations of the existing literature argue for prospective, well-controlled follow-up studies with recurrent AMH measurements to determine whether carriers might be at risk for low ovarian reserve and to definitively guide care., Study Funding/competing Interests: This study was partially financially supported by a personal grant for Inge A.P. Derks-Smeets, kindly provided by the Dutch Cancer Society (Grant Number UM 2011-5249). Theodora C. van Tilborg, Inge A.P. Derks-Smeets, Anna M.E. Bos, Jan C. Oosterwijk, Christine E. de Die-Smulders, Lizet E. van der Kolk, Wendy A.G. van Zelst-Stams, Maria E. Velthuizen, Marinus J.C. Eijkemans and Margreet G.E.M. Ausems have nothing to disclose. Ron J. van Golde has received unrestricted research grants from Ferring and Merck Serono, outside the submitted work. Annemieke Hoek received an unrestricted educational grant from Ferring pharmaceutical BV, The Netherlands and a speaker's fee for post graduate education from MSD pharmaceutical company, outside the submitted work. Joop S.E. Laven has received unrestricted research grants from Ferring, Merck Serono, Merck Sharpe & Dome, Organon, and Schering Plough, outside the submitted work. Frank J.M. Broekmans is a member of the external advisory board for Merck Serono (The Netherlands), outside the submitted work., Trial Registration Number: NTR no. 4324., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Anti-Müllerian hormone (AMH) is currently used as an ovarian reserve marker for individualized fertility counseling, but very little is known of individual AMH decline in women. This study assessed whether the decline trajectory of AMH is uniform for all women, and whether baseline age-specific AMH levels remain consistently high or low during this trajectory., Methods: A total of 3326 female participants from the population-based Doetinchem Cohort Study were followed with five visits over a 20-year period. Baseline age was 40 ± 10 years with a range of 20-59 years. AMH was measured in 12,929 stored plasma samples using the picoAMH assay (AnshLabs). Decline trajectories of AMH were studied with both chronological age and reproductive age, i.e., time to menopause. Multivariable linear mixed effects models characterized the individual AMH decline trajectories., Results: The overall rate of AMH decline accelerated after 40 years of age. Mixed models with varying age-specific AMH levels and decline rates provided the significantly best fit to the data, indicating that the fall in AMH levels over time does not follow a fixed pattern for individual women. AMH levels remained consistent along individual trajectories of age, with an intraclass correlation coefficient (ICC) of 0.87. The ICC of 0.32 for AMH trajectories with time to menopause expressed the large variation in AMH levels at a given time before the menopause. The differences between low and high age-specific AMH levels remained distinguishable, but became increasingly smaller with increasing chronological and reproductive age., Conclusions: This is the first study to characterize individual AMH decline over a long time period and broad age range. The varying AMH decline rates do not support the premise of a uniform AMH decline trajectory. Although age-specific AMH levels remain consistently high or low with increasing age, the converging trajectories and variance of AMH levels at a given time before menopause shed doubt on the added value of AMH to represent individualized reproductive age.

Study Question: Is there a relationship between serum anti-Müllerian hormone (AMH) level and cardiovascular disease (CVD) risk in premenopausal women?, Summary Answer: There are indications that premenopausal women with very low ovarian reserve may have an unfavorable CVD risk profile., What Is Known Already: Age at menopause is frequently linked to CVD occurrence. AMH is produced by ovarian antral follicles and provides a measure of remaining ovarian reserve Literature on whether AMH is related to CVD risk is still scarce and heterogeneous., Study Design, Size, Duration: Cross-sectional study in 2338 women (age range of 20-57 years) from the general population, participating in the Doetinchem Cohort Study between 1993 and 1997., Participants/materials, Setting, Methods: CVD risk was compared between 2338 premenopausal women in different AMH level-categories, with adjustment for confounders. CVD risk was assessed through levels of systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol and glucose, in addition to a summed score of CVD risk factors. Among other factors, analyses were corrected for smoking, oral contraceptive use and BMI., Main Results and the Role of Chance: The relationship of serum AMH levels with CVD risk factor outcomes was nonlinear. Women with AMH levels <0.16 µg/l had 0.11 (95% confidence intervals (CIs) 0.01; 0.21) more metabolic risk factors compared with women with AMH levels ≥0.16 µg/l. There was no association of individual risk factor levels with AMH levels, besides a tendency towards lower total cholesterol levels of 0.11 mmol/l (95% CI -0.23; 0.01) in women with AMH levels <0.002 µg/l compared with women with AMH levels ≥0.16 µg/l. Although not statistically significant, these effect sizes were larger in women below 40 years of age., Limitations, Reasons for Caution: Causality and temporality of the studied association cannot be addressed here. Moreover, the clinical and statistical significance of the results of this exploratory study should be interpreted with caution due to the absence of adjustment for multiple statistical testing., Wider Implications of the Findings: This population-based study supports previous findings that premenopausal women with very low AMH levels may have an increased CVD risk. It lays the groundwork for future research to focus on this group of women. Longitudinal studies with more sensitive AMH assays may furthermore help better understand the implications of these results., Study Funding/competing Interest: No financial support was received for this research or manuscript. The Doetinchem Cohort Study is conducted and funded by the Dutch National Institute for Public Health and the Environment F.J.M.B. has received fees and grant support from Merck Serono, Gedeon Richter, Ferring BV and Roche., Trial Registration Number: N/A., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Variability in operating room (OR) time causes overutilization and underutilization of the available ORs. There is evidence that for a given type of procedure, the surgeon is the major source of variability in OR time. The primary aim was to quantify the variability between surgeons and anesthesiologists. As illustration, the value of modeling the individual surgeons and anesthesiologist for OR time prediction was estimated., Methods: OR data containing 16,480 cases were obtained from a general surgery department. The total amount of variability in OR time accounted for by the type of procedure, first and second surgeon, and the anesthesiologist was determined with the use of linear mixed models. The effect on OR time prediction was evaluated as reduction in overtime and idle time per case., Results: Differences between first surgeons can account for only 2.9% (2.0%-4.2%) of the variability in OR time. Differences between anesthesiologists can account for 0.1% (0.0%-0.3%) of the variability in OR time. Incorporating the individual surgeons and anesthesiologists led to an average reduction of overtime and idle time of 1.8 (95% confidence interval, 1.7-2.0, 10.5% reduction) minutes and 3.0 (95% confidence interval, 2.8%-3.2, 17.0% reduction) minutes, respectively., Conclusions: In comparison with the type of procedure, differences between surgeons account for a small part of OR time variability. The impact of differences between anesthesiologists on OR time is negligible. A prediction model incorporating the individual surgeons and anesthesiologists has an increased precision, but improvements are likely too marginal to have practical consequences for OR scheduling.

Introduction: In this prospective cohort study we aimed to investigate the hypothesis that fluctuations in anti-Müllerian hormone levels stem from fluctuations in the number of antral follicles., Material and Methods: Repeated measurements of anti-Müllerian hormone and antral follicles (follicles 2-8 mm) were performed in 44 women with a regular cycle, during one menstrual cycle. If our hypothesis that anti-Müllerian hormone fluctuations stem from fluctuations in the antral follicles is correct, a fluctuation in the antral follicles would result in an equal and parallel shift in anti-Müllerian hormone. Hence, the difference between antral follicles and anti-Müllerian hormone would remain constant over time. A mixed model analysis, assessing the stability between anti-Müllerian hormone and antral follicles, was performed using the difference between log antral follicles and log anti-Müllerian hormone. Cohen's D was calculated for the largest of fixed effects in order to assess stability in relative distance between antral follicles and anti-Müllerian hormone. To assess if fluctuation in anti-Müllerian hormone or antral follicles originated from between-subject fluctuation, or from within subject fluctuation, the intra-class correlation coefficient was calculated., Results: Mixed model analysis and Cohen's D (0.12) confirmed the stability of the difference between log antral follicles and log anti-Müllerian hormone and so confirmed our hypothesis. The good intra-class correlation coefficient (0.73) indicated a small contribution of within-subject variation to anti-Müllerian hormone fluctuations., Conclusions: Fluctuations in anti-Müllerian hormone levels parallel fluctuations in antral follicles, suggesting that anti-Müllerian hormone levels are closely linked to variation in the antral follicles. This knowledge adds to the basic understanding of the origin of anti-Müllerian hormone and could aid in interpretation of individual anti-Müllerian hormone levels., (© 2016 Nordic Federation of Societies of Obstetrics and Gynecology.)

Study Question: Do ovarian reserve tests (ORTs) predict age at natural menopause (ANM) in a cohort of healthy women with a regular menstrual cycle?, Summary Answer: Of the ORTs researched, anti-Müllerian hormone (AMH) alone predicts age at menopause. However, its predictive value decreased with increasing age of the woman, prediction intervals were broad and extreme ages at menopause could not be predicted., What Is Known Already: A fixed interval is hypothesized to exist between ANM and age at loss of natural fertility. Therefore, if it is possible to predict ANM, one could identify women destined for early menopause and thus at higher risk for age-related subfertility. Of ORTs researched in the prediction of ANM, AMH is the most promising one., Study Design, Study Size and Duration: A long-term, extended follow-up study was conducted, results of the first follow-up round were previously published. Two hundred and sixty-five normo-ovulatory women (21-46 years) were included between 1992 and 2001, 49 women (18.5%) could not be reached in the current follow-up round., Participants, Setting, Methods: Two hundred and sixty-five healthy normo-ovulatory women were included, recruited in an Academic hospital. We measured baseline AMH, follicle-stimulating hormone and the antral follicle count (AFC). At follow-up (2009 and 2013), menopausal status was determined via questionnaires. Cox regression analysis calculated time to menopause (TTM) using age and ORT. A check of (non-) proportionality of the predictive effect of AMH was performed. A Weibull survival model was used in order to predict individual ANM., Main Results and the Role of Chance: In total, 155 women were available for analyses. Eighty-one women (37.5%) had become post-menopausal during follow-up. Univariable Cox regression analysis demonstrated age and ORTs to be significantly correlated with TTM. Multivariable Cox regression analysis, adjusting for baseline age and smoking; however, demonstrated AMH alone to be an independent predictor of TTM (Hazard Ratio 0.70, 95% Confidence Interval 0.56-0.86, P-value <0.001). A (non-)proportionality analysis of AMH over time demonstrated AMH's predictive effect to decline over time., Limitations, Reason for Caution: The observed predictive effect of AMH became less strong with increasing age of the woman. Individual AMH-based age at menopause predictions did not cover the full range of menopausal ages, but did reduce the variation around the predicted ANM from 20 to 10.1 years., Wider Implications of the Findings: Age-specific AMH levels are predictive for ANM. Unlike in our previous publication however, a declining AMH effect with increasing age was observed. This declining AMH effect is in line with recent long-term follow-up data published by others. Moreover, the accompanying predictive inaccuracy observed in individual age at menopause predictions based on AMH, makes this marker currently unsuitable for use in clinical practice., Study Funding/competing Interests: No external funds were used for this study. M.D., M.J.C.E, S.L.B., G.J.S. and I.A.J.R. have nothing to declare. J.S.E.L. has received fees and grant support from the following companies (in alphabetical order): Ferring, Merck-Serono, MSD, Organon, Serono and Schering Plough. F.J.M.B. receives monetary compensation: member of the external advisory board for Merck Serono, the Netherlands; consultancy work for Gedeon Richter, Belgium; educational activities for Ferring BV, the Netherlands; strategic cooperation with Roche on automated AMH assay development., (© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Motivation: Class predicting with gene expression is widely used to generate diagnostic and/or prognostic models. The literature reveals that classification functions perform differently across gene expression datasets. The question, which classification function should be used for a given dataset remains to be answered. In this study, a predictive model for choosing an optimal function for class prediction on a given dataset was devised., Results: To achieve this, gene expression data were simulated for different values of gene-pairs correlations, sample size, genes' variances, deferentially expressed genes and fold changes. For each simulated dataset, ten classifiers were built and evaluated using ten classification functions. The resulting accuracies from 1152 different simulation scenarios by ten classification functions were then modeled using a linear mixed effects regression on the studied data characteristics, yielding a model that predicts the accuracy of the functions on a given data. An application of our model on eight real-life datasets showed positive correlations (0.33-0.82) between the predicted and expected accuracies., Conclusion: The here presented predictive model might serve as a guide to choose an optimal classification function among the 10 studied functions, for any given gene expression data., Availability and Implementation: The R source code for the analysis and an R-package 'SPreFuGED' are available at Bioinformatics online., Contact: v.l.jong@umcutecht.nl, Supplementary Information: Supplementary data are available at Bioinformatics online., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)