Stratified Groups Research Articles

Abstract Su1204: Impact of Hypothermia vs. Normothermia Temperature Management Based on Body Temperature at Hospital Arrival on 30-Day Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients: A Nationwide, Retrospective Study in Japan

Introduction: Temperature management (TM) to prevent fever is crucial to mitigate neurological deterioration post-cardiac arrest. Whether hypothermic TM (h-TM) is superior or equal to normothermic TM (n-TM) after out-of-hospital cardiac arrest (OHCA) is debatable, prompting ongoing effects to identify patients who might benefit more from h-TM. We hypothesized that effect of TM would differ based on body temperature at hospital arrival. Aim: Explore which post-cardiac arrest patient subsets might benefit from h-TM by stratifying them based on body temperature at hospital arrival. Methods: This retrospective, observational study used data from the OHCA registry in Japan. Patients 18 years and older who experienced OHCA due to medical cause and received TM in the intensive care unit were included. Primary outcome measure was 30-day favorable neurological outcomes, defined as a Cerebral Performance Category score of 1 or 2. Patients were stratified into groups based on body temperature at hospital arrival: normothermia (36.0-38.0°C), hypothermia (<36.0°C), and hyperthermia (>38.0°C). Effect of TM post-cardiac arrest (h-TM [32-34°C] or n-TM [35-36°C]) was evaluated in each stratified group. Univariable and multivariable logistic regression analysis was used for comparison. Adjusted odds ratio (OR) for favorable neurological outcome with h-TM was calculated using n-TM as a reference. Hyperthermia was excluded from multivariable analyses due to small sample size. Results: We analyzed 3,044 patients, 1,273 in the normothermia group, 1,747 in the hypothermia group, and 24 in the hyperthermia group. Numbers of patients with favorable neurological outcomes were as follows: 530/1,273 (41.6%) in the normothermia group, 584/1,747 (33.4%) in the hypothermia group, and 4/24 (16.7%) in the hyperthermia group. There were no differences in favorable 30-day neurological outcomes between h-TM and n-TM in any stratified group in the univariable analysis: normothermia (h-TM 323/785 [41.2%] vs. n-TM 207/488 [42.4%], p=0.66); hypothermia (411/1,185 [34.7%] vs. 173/562 [30.8%], p=0.11); hyperthermia (3/13 [23.1%] vs. 1/11 [9.1%], p=0.59). Multivariable analysis also showed no differences: normothermia (OR: 0.96, 95% CI: 0.72-1.26), hypothermia (OR: 1.10, 95% CI: 0.85-1.42). Conclusion: TM (h-TM vs. n-TM) did not significantly affect 30-day neurological outcomes, regardless of initial temperature at hospital arrival.

Abstract 4144577: Temporal Trends in Attainment of LDL-c Goals Post Coronary Artery Bypass Grafting (CABG): Data From a Large Integrated Healthcare System

Introduction: Multisociety guidelines in secondary atherosclerotic cardiovascular disease (ASCVD) cholesterol goals have evolved over time. We aim to identify temporal trends in low density lipoprotein cholesterol (LDL-c) and statin use in a post coronary artery bypass grafting (CABG) population. Methods: This is a retrospective study of Kaiser Permanente Northern California members who underwent CABG from 2008 to 2019. Patients were stratified according to three time frames (2008-2013, 2014-2018, 2019) based on the release of multisociety guidelines in 1999, 2013 and 2018. LDL-c goal was defined as a last available value less than 70 mg/dL at 1 year follow up. Lipid lowering therapies were identified through pharmacy records. Cox proportional hazard modeling was used to identify major adverse cardiovascular event (MACE) free survival at up to 12 years follow up. Results: The cohort included 6422 patients, mean age 64.9 years, 83% male, with baseline LDL-c 95.9 mg/dL. Of the cohort, 47% of patients achieved an LDL-c < 70 mg/dL at 1-year follow up. Of the stratified groups, the 2019 cohort demonstrated the highest attainment of LDL-c goal (65%, N=392) compared to 2008-2013 cohort (41%, N=1197) and 2014-2018 cohort (57%, N=1406) (Table 1). A relative increase in high dose statin monotherapy and a decrease in low/moderate dose statin monotherapy was temporally demonstrated in recent cohorts. There was a positive correlation between increasing year and attainment of LDL-c goal (R2=0.916) (Figure 1). Attainment of LDL-c <70 at 1 year post CABG was associated with higher MACE free survival (log-rank p=0.057). Conclusions: Recent cholesterol guidelines post ASCVD have a stronger emphasis on specified LDL-c goals which is associated with increased attainment of LDL-c <70 and improved MACE free survival in our post CABG patients.

Global well‐posedness of space‐time fractional diffusion equation with Rockland operator on graded lie group

In this article, we examine the general space‐time fractional diffusion equation for left‐invariant hypoelliptic homogeneous operators on graded Lie groups. Our study covers important examples such as the time fractional diffusion equation, the space‐time fractional diffusion equation when diffusion is under the influence of sub‐Laplacian on the Heisenberg group, or general stratified Lie groups. We establish the global well‐posedness of the Cauchy problem for the general space‐time fractional diffusion equation of the Rockland operator on a graded Lie group in the associated Sobolev spaces and also develop some regularity estimates for it.

Differential Analysis of Surgical Treatment Modalities in T2N0M0 Bladder Cancer Patients: A Novel Propensity Score-Based Cohort Study

ObjectiveThis study explored prognostic differences between radical cystectomy (RC), tri-modality treatment (TURBt combined with radiotherapy and chemotherapy, TMT) and electrocautery (EC) and partial cystectomy (PC) for T2N0M0 MIBC. Materials and MethodsIn the SEER database (2004-2015, 2018-2020), we identified patients with T2N0M0 bladder cancer receiving RC, TMT, EC or PC treatment. To minimize confounding factors, 1:1 propensity score matching (PSM) with a 0.1 caliper was conducted. Kaplan-Meier analysis and log-rank tests were used to compare survival rates. Cox analysis identified independent prognostic factors, tumor size, and age, stratified treatment groups, and further Kaplan-Meier analysis of CSS was performed in matched cohorts. ResultThis study included 6526 patients with T2N0M0 MIBC. Among them, 348 (5.33%) were in the PC group, 309 (4.73%) were in the EC group, 1833 (28.09%) were in the TMT group, and 4036 (61.84%) were in the RC group. After 1:1 propensity score matching, RC showed improved CSS (HR=0.67, 95%CI 0.47-0.95, and PC also benefited (HR=0.97, 95%CI 0.69-1.36) compared to EC. While TMT showed a worse end (HR=1.41, 95%Cl 1.03-1.92) compared to EC. Cox analysis was used to stratify tumor size and age for subgroup analysis. Results for tumor size subgroups were aligned with PSM findings. In the age-stratified subgroups, patients aged <67 years, both RC (HR=0.54, P=0.107) and TMT(HR=0.91, P=0.785) showed better prognoses compared to EC treatment, while PC treatment showed worse prognoses compared to EC treatment (HR=1.23, P=0.542).; for 68-77 years, RC (0.64, P=0.1436) and PC (HR=0.46, P=0.0283)had advantages, and PC is more recommended. For >78 years, RC had superior CSS over EC and PC, whereas TMT had the poorest prognosis. ConclusionIn clinical T2N0M0 MIBC, overall, RC outperformed focal-tumor therapy and PC, irrespective of tumor size. However, considering age, we recommend PC treatment for patients aged 68-77 and EC for those aged >78 years. Micro-AbstractThis study compared radical cystectomy (RC), focal-tumor therapy combined with radiotherapy and chemotherapy (TMT and EC), and partial cystectomy (PC) for non-metastatic muscle-invasive bladder cancer. Using SEER data and a series of statistical analyses, overall, RC outperformed focal-tumor therapy and PC, irrespective of tumor size. However, considering age, we recommend PC treatment for patients aged 68-77 and EC for those aged >78 years. In contrast, for patients younger than 67 years of age, we recommend RC for those who can tolerate surgical treatment and TMT for those who can't.

Short versus conventional DAPT in patients undergoing PCI with ultra-thin DES by renal function: an analysis from the HOST-IDEA trial

Abstract Background Patients with impaired renal function are known to have an elevated risk of both ischemic and bleeding events following percutaneous coronary intervention (PCI). However, there is insufficient data available on the optimal duration of dual antiplatelet therapy (DAPT), especially with the latest generation of drug-eluting stent (DES)s. Objective We investigated to assess the efficacy and safety of abbreviated duration of DAPT in patients undergoing PCI with 3rd generation DESs based on their renal function. Methods In this prespecified subgroup analysis of the HOST-IDEA trial, a total of randomized 1997 patients with available baseline estimated glomerular filtration rate (eGFR) were categorized into three groups: high eGFR (&amp;gt;90 mL/min), intermediate eGFR (60 to 90 mL/min), and low eGFR (&amp;lt;60 mL/min). The primary outcome assessed during the 1-year follow-up period was net adverse clinical events (NACE). Ischemic and bleeding endpoints were also evaluated. Results Compared to intermediate or high eGFR groups, the low eGFR group resulted in significantly worse outcomes (P &amp;lt; 0.001). 3-6 month DAPT was associated with similar risk of NACE across all eGFR groups (High eGFR: HR: 0.91; 95% CI: 0.38-2.20; Intermediate eGFR: HR: 0.76; CI: 0.33-1.73; Low eGFR: HR: 0.99; CI: 0.51-1.92). There was also no significant difference in target lesion failure (HR: 0.95; CI: 0.32-2.83, HR: 0.77; CI: 0.29-2.06, and HR: 1.14; CI: 0.47-2.75) and major bleeding (HR: 0.84; CI: 0.19-3.74, HR: 0.59 CI: 0.14-2.48; and HR 0.83 CI: 0.34-2.05) among all stratified eGFR groups. This effect was also consistent in patients of end stage of renal disease (eGFR &amp;lt;15 mL/min). Conclusions In patients undergoing PCI with third generation DESs, short DAPT was comparable to conventional DAPT regardless of their baseline renal function.

Influencing factors of antibody response after 2 doses of inactivated COVID-19 vaccine among adults aged ≥18 years in Chongqing, China: A cross-sectional serological study.

The study aimed to explore the influencing factors after 2 doses of inactivated COVID-19 vaccines (Sinopharm/BBIBP-CorV) in the real world. We conducted a cross-sectional serological study involving 316 volunteers aged ≧ 18 years from 7 vaccination hospitals in the Yubei districts, Yuzhong districts, and Jiulongpo districts of Chongqing. Serum samples were obtained about 1 month after 2 dose vaccination, and Nabs were tested using the pseudovirus-based neutralizing assay. Chi-square or Fisher exact tests were used to analyze the seropositive rates, while the Kruskal-Wallis H or Mann-Whitney U tests were used to analyze differences in Nabs level among stratified groups. Logistic regression analyses were conducted to identify the influencing factors. The results showed that seropositive rates was 76.27% and the GMT was 26.13 (95% CI: 23.03-29.66) after 2 doses of COVID-19 inactivated vaccination. The risk of being seropositive in 18 to 29, 30 to 39, 40 to 49, 50 to 59, and 60 to 69 years were 12.808-fold, 8.041-fold, 7.818-fold, 6.275-fold, 1.429-fold compared with the people aged ≥ 70 years (P < .05), and the risk of being seropositive of intervals 15 to 21 and 22 to 28 days were 0.273-fold and 0.286-fold compared with >28 days (P < .05), respectively. In conclusion, age may be a risk factor for reduced antibody production, and longer vaccination intervals-may be a protective factor that increases antibody production. These findings contribute to informing future vaccination strategies.

Monodromy of stratified braid groups, II

The space of monic squarefree polynomials has a stratification according to the multiplicities of the critical points, called the equicritical stratification. Tracking the positions of roots and critical points, there is a map from the fundamental group of a stratum into a braid group. We give a complete determination of this map. It turns out to be characterized by the geometry of the translation surface structure on CP1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathbb{C}\\mathbb{P}^1$$\\end{document} induced by the logarithmic derivative df/f\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{d}f/f$$\\end{document} of a polynomial in the stratum.

On subelliptic equations on stratified Lie groups driven by singular nonlinearity and weak L 1 data

On subelliptic equations on stratified Lie groups driven by singular nonlinearity and weak L 1 data

Weighted Rellich and Hardy inequalities in L p(·) spaces

Abstract In this note we prove weighted Rellich–Sobolev and Hardy–Sobolev inequalities in variable exponent Lebesgue spaces L p ⁢ ( ⋅ ) ⁢ ( 𝔾 ) {L^{p(\,\cdot\,)}(\mathbb{G})} defined on stratified homogeneous groups 𝔾 {\mathbb{G}} . To derive the main results, we rely on weighted estimates for the Riesz potential operators in L p ⁢ ( ⋅ ) ⁢ ( 𝔾 ) {L^{p(\,\cdot\,)}(\mathbb{G})} , where 𝔾 {{\mathbb{G}}} is a general homogeneous group. The results are new even for the Abelian (Euclidean) case 𝔾 = ( ℝ d , + ) {\mathbb{G}=(\mathbb{R}^{d},+)} and the Heisenberg groups 𝔾 = ℍ n {\mathbb{G}={\mathbb{H}}^{n}} . The main statements are obtained for variable exponents satisfying the condition that the Hardy–Littlewood maximal operator is bounded in appropriate variable exponent Lebesgue spaces. We also give some quantitative estimates for the norms of integral operators involved in derived estimates.

Difference in Cardiac Response after Transcatheter Aortic Valve Implantation according to Flow and Gradient Pattern.

In patients undergoing transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS), data on the differences in subsequent cardiac structure and function among stratified groups with flow gradient patterns through the aortic valve are insufficient. In this large multicenter study, 4,523 patients undergoing TAVI for severe AS between 2013 and 2019 were divided into 3 groups according to the following criteria: (1) high-gradient AS (HG-AS) (mean pressure gradient [MPG] ≥40 mmHg), (2) classical low-flow low-gradient AS (cLFLG-AS) (MPG <40 mmHg, left ventricular [LV] ejection fraction [LVEF] <50%), and (3) paradoxical low-flow low-gradient AS (pLFLG-AS) (MPG <40 mmHg, LVEF ≥50% but stroke volume index [SVi] <35 mL/m2). Echocardiography was performed at baseline, post-procedure, and 1 year post-TAVI. 3,697, 507, and 319 patients had HG-AS, cLFLG-AS, and pLFLG-AS, respectively. After adjusting for clinical factors, cLFLG-AS and pLFLG-AS had an approximately 1.5-fold higher 2-year all-cause mortality compared with HG-AS. During 1 year following TAVI, compared with HG-AS, cLFLG-AS showed greater reduction of LV systolic diameter (LVDs) and LV diastolic diameter (LVDd) and greater increase of LVEF (p<0.001 for all), and changes in LV mass index (LVMi) and SVi were comparable (p=0.915 and p=0.821, respectively). However, pLFLG-AS demonstrated less reduction of LVDs and LVDd (p=0.039 and p=0.001, respectively), less improvement of LVEF and LVMi (p=0.045 and p<0.001, respectively), and comparable change in SVi (p=0.364). During 1 year post-TAVI, compared with HG-AS, cLFLG-AS achieves smaller LV diameters, greater increase in LVEF, and comparable regression of LVMi, whereas pLFLG-AS does not.

Integrative radiopathomics model for predicting progression-free survival in patients with nonmetastatic nasopharyngeal carcinoma

PurposeTo construct an integrative radiopathomics model for predicting progression-free survival (PFS) in nonmetastatic nasopharyngeal carcinoma (NPC) patients.Methods357 NPC patients who underwent pretreatment MRI and pathological whole-slide imaging (WSI) were included in this study and randomly divided into two groups: a training set (n = 250) and validation set (n = 107). Radiomic features extracted from MRI were selected using the minimum redundancy maximum relevance and least absolute shrinkage and selection operator methods. The pathomics signature based on WSI was constructed using a deep learning architecture, the Swin Transformer. The radiopathomics model was constructed by incorporating three feature sets: the radiomics signature, pathomics signature, and independent clinical factors. The prognostic efficacy of the model was assessed using the concordance index (C-index). Kaplan-Meier curves for the stratified risk groups were tested by the log-rank test.ResultsThe radiopathomics model exhibited superior predictive performance with C-indexes of 0.791 (95% confidence interval [CI]: 0.724–0.871) in the training set and 0.785 (95% CI: 0.716–0.875) in the validation set compared to any single-modality model (radiomics: 0.619, 95% CI: 0.553–0.706; pathomics: 0.732, 95% CI: 0.662–0.802; clinical model: 0.655, 95% CI: 0.581–0.728) (all, P < 0.05). The radiopathomics model effectively stratified patients into high- and low-risk groups in both the training and validation sets (P < 0.001).ConclusionThe developed radiopathomics model demonstrated its reliability in predicting PFS for NPC patients. It effectively stratified individual patients into distinct risk groups, providing valuable insights for prognostic assessment.

Latent Class Analysis of Sexual Partnerships and Substance Use Across Generations.

Sexually transmitted infections (STIs) remain an important public health concern for people of all age groups, with older age groups experiencing a notable increase in STI burden. Historically, most research into STI risk behaviors has focused on adolescents and young adults, leaving a paucity of research on the ways STI risk factors change over the life course. Additionally, age and cohort trends in STI risk factors can be challenging to investigate with standard statistical tools as they can be collinear and are subject to sociocultural and generational influences. To help address these issues, we used multi-group latent class analysis to identify and compare risk behavior profiles defined by responses to three sexual activity and three substance use variables, across and within four age groups. We identified six behavior profiles in the unstratified dataset and five behavior profiles in each of the four age stratified groups. The five behavior profiles identified in each of the age categories appear to reflect a similar set of five underlying profile "archetypes," with the exact composition of each age category's five profiles varying in the magnitude that specific behaviors are endorsed. Interestingly, despite the similarity of profiles across the four age groups, analyses indicate that the experience of belonging to any one of these five archetypes differs by age group. This variance is likely due group specific age, period, and cohort effects, and may indicate that, when estimating one's STI risk, it is better to compare them to their peers than to the population as a whole.

Exploring perceptions of anti-vaping message themes: A qualitative study of Australian adolescents and adults.

Minimising electronic cigarette (e-cigarette) uptake and encouraging vaping cessation have become important components of public health agendas. Given the success of well-designed anti-smoking campaigns, attention has turned to developing health communications that target vaping. Although prior work has identified a range of potentially effective campaign messages, several gaps in the literature remain. We aimed to (i) identify message themes perceived to be effective at minimising e-cigarette use and (ii) elicit opinion on how these message themes could be optimised in terms of message execution and delivery. Focus groups (n = 16) were conducted with adolescents (14-15 and 16-17 year olds), young adults (18-24 year olds), and adults (25-39 year olds). The groups reported on message themes they believed would assist with minimising e-cigarette use. They then provided feedback on 14 message themes developed by the research team. Data were analysed using reflexive thematic analysis. Groups discussed a range of message themes they believed would be effective. These included themes focused on the health harms associated with vaping, the chemical ingredients in e-cigarettes, use dependence, and social attitudes to use. Groups discussed the importance of using evidence-based personal testimonies, and reported that messages would be most effectively communicated via social media, in public places, and at point of sale. Results build on existing research by identifying message themes perceived to be most effective, and how these would best be executed. Results have the potential to inform the development of co-designed health communication campaigns addressing youth vaping. Using a stratified focus group methodology, we collected rich and detailed qualitative data on Australians' perceptions of anti-vaping message themes. Themes considered most effective were those that addressed the health harms of vaping, the chemical ingredients in e-cigarettes, social consequences of use and the impacts of dependence. We recommend further work to develop and trial a range of specific anti-vaping messages based on the themes identified as having the most potential. This process should include iterative co-design with the target audience to optimise future health communication campaigns.

Results of existence and uniqueness for the Cauchy problem of semilinear heat equations on stratified Lie groups

The aim of this paper is to give existence and uniqueness results for solutions of the Cauchy problem for semilinear heat equations on stratified Lie groups G with the homogeneous dimension N. We consider the nonlinear function behaves like |u|α or |u|α−1u(α>1) and the initial data u0 belongs to the Sobolev spaces Lsp(G) for 1<p<∞ and 0<s<N/p. Since stratified Lie groups G include the Euclidean space Rn as an example, our results are an extension of the existence and uniqueness results obtained by F. Ribaud on Rn to G. It should be noted that our proof is very different from it given by Ribaud on Rn. We adopt the generalized fractional chain rule on G to obtain the estimate for the nonlinear term, which is very different from the paracomposition technique adopted by Ribaud on Rn. By using the generalized fractional chain rule on G, we can avoid the discussion of Fourier analysis on G and make the proof more simple.

Sparse bounds for oscillating multipliers on stratified groups

Sparse bounds for oscillating multipliers on stratified groups

Socioeconomic Factors Determining Multidimensional Child Poverty Groups in Central America: A Measurement Proposal from the Wellbeing Approach Using a Comprehensive Set of Children’s Rights

This article aims to show that multidimensional child poverty (MCP) is determined by several socioeconomic factors that influence the formation of stratified groups of poor children under five years of age living in Central America. This study advocates for a comprehensive set of children's rights with the purpose of addressing the different facets of child poverty from the perspective of child well-being, in order to estimate the incidence of MCP, by including multiple childhood deprivations and socioeconomic determinants. Child-specific indicators and household deprivation indicators are considered in the estimation of MCP. The study also states that child poverty is a complex concept, which includes the various types of deprivations experienced by children in the Central American societies and their deprivations are considered as the denial of children’s rights. Therefore, the MCP is estimated based on a conditional latent class analysis that includes not only manifest deprivation variables, but also socioeconomic determinants that help to better predict the incidence and probabilities of children being multidimensionally poor according to different poverty strata. The socioeconomic factors that show high risks of MCP are rural areas, indigenous children, young mothers and low levels of education attained by the head of the household, among others. One of the reasons to investigate the MCP for Belize and El Salvador is because there are few studies that address this problem for these countries and this research sheds light on the characteristics of early childhood poverty. The results indicate that the incidence of MCP is 49% in Belize and 76% in El Salvador. The research work concludes that the International Rights of the Child provide the opportunity to implement comprehensive social policies in Central America to eradicate child poverty.

Association between number of confidants and adolescent anxiety/depression: a school-based study

BackgroundHaving no or few confidants is found to be associated with more severe mental health problems and a higher prevalence of depression in adults, but research examining this association in adolescents is scarce. Social relationships may be particularly critical during adolescence, as it is an important developmental period during which vulnerability to mental health problems increases. The present study examined the relationship between having no or few confidants and anxiety/depressive symptoms in adolescents.MethodsCross-sectional self-report survey targeting 7–12th grade students (age range: 12–18) was conducted in public junior and senior high schools in Mie and Kochi, Japan. Data from 17,829 students (49.7% boys) were analyzed. Associations between anxiety/depressive symptoms (12-item General Health Questionnaire; score range: 0–12) and the number of confidants (None, 1–3, or ≥ 4) were examined using multilevel regression analyses. The analyses were stratified by gender and school level (junior/senior high), and adjusted for experiences of being physically abused and bullied and the interactions of these experiences with the number of confidants.ResultsHaving no or 1–3 confidants was associated with more anxiety/depressive symptoms, compared to having ≥ 4 confidants (p < 0.001) in all stratified groups. Having no confidants was associated with more anxiety/depressive symptoms than having 1–3 confidants (p < 0.001); in senior high boys, no difference was observed between having no confidants and having 1–3 confidants. In addition, in senior high boys, victims of bullying who have confidants reported significantly less anxiety/depressive symptoms than the victims who have no confidants (p < 0.01).ConclusionsAdolescents who had no or few confidants had more anxiety/depressive symptoms. Attention needs to be paid to better identify these adolescents, and avenues to support them need to be established.

Prevalence analysis of Chagas disease by age group in an endemic region of Brazil: possible scenario of active vectorial transmission

ObjectivesChagas disease (CD) is an infectious disease that predominantly affects poor and vulnerable populations. The last estimate conducted by the World Health Organization in Latin America regarding the prevalence of CD occurred more than 10 years ago. However, there is a scarcity of data assessing the magnitude of CD in populations residing in considered high-risk regions. Therefore, this study aimed to assess the seroprevalence of CD in an endemic region in Northern Minas Gerais through serologic screening. MethodsThis is a prevalence study conducted in the municipalities of Catuti, Mato Verde, Mirabela, Montes Azul, and São Francisco, Minas Gerais, Brazil. Data collection occurred between December 2021 and December 2022, involving a questionnaire with closed-ended questions. The variables analyzed included serologic test results, stratified age groups, health indicators, and housing conditions. ResultsOf the 2978 participants, 272 individuals (9.1%) tested positive for CD serology. In the age group of 4 to 14 years, 15 to 49 years, and 50 years or older, the prevalence of positive serology was 0.8% (95% confidence interval [CI] 0.16-1.43), 5.5% (95% CI 4.20-6.83), and 18.8% (95% CI 16.48-21.11), respectively. Among the participating municipalities, Mato Verde had the highest prevalence of positive serology for CD (17%). For participants aged 4 to 14 years with positive serology for CD, first-degree relatives were invited to undergo serologic testing. It was possible to collect samples from relatives of all participants in this age group. However, none of the relatives tested positive. ConclusionThis study identified a 9.1% prevalence of individuals affected by CD who were unaware of their condition. In addition, having infected children in the 4 to 14 age group with mothers with negative serology would rule out congenital transmission of the disease.

P-148 Humid versus dry culture: impact on euploidy, live birth sex ratio and clinical outcomes

Abstract Study question Does humidity have an impact on top-quality blastocyst rate, ploidy, live birth sex ratio and clinical outcomes? Summary answer Humid culture conditions in time-lapse incubators may enhance clinical outcomes, particularly in autologous cycles, without biasing euploidy or newborn sex. What is known already Recent advances in assisted reproductive technology have focused on improving embryo culture conditions and incubators are becoming more sophisticated. Although culture conditions such as oxygen and temperature are well-studied, the optimal humidity level remains uncertain. Dry atmospheres favour higher evaporation of culture media compared to humid conditions, increasing its osmolality. This appears to be detrimental to several animal model embryos: developmental arrest, changes in gene expression and epigenetic alterations in the embryos. Previous studies have shown than incubator humidification improves clinical outcomes and embryonic development. However, other studies showed no significant improvements. Study design, size, duration A single center retrospective study was performed. Data included a total of 793 cycles of IVF/ICSI between January 2019 and May 2023. Participants/materials, setting, methods 793 cycles of IVF/ICSI from 734 patients were studied. Study population was categorized in autologous (n = 544) and egg-donation (n = 249) cycles. A total of 5909 embryos were included in the study. Patients were randomly distributed in two distinct cohorts at the moment of their treatment: dry condition (DC) and humid condition (HC). Blastocyst quality (BR), biochemical pregnancy (BPR), implantation rate (IR), live birth rate (LBR) were studied. Ploidy rate and LB sex ratio was also studied. Main results and the role of chance In egg donation cycles, no differences were observed between HC and DC groups in the rates of top-quality blastocysts (61.5 HC vs 64.4% DC), BPR, (71.1% HC vs 71.2% DC), IR (53.8% HC vs. 59.2% DC) or LBR (51.9% HC vs. 44.8% DC). However, autologous cycles showed an improvement when humid conditions were used. BR and IR were higher in humid conditions (BR: 58.8% HC vs. 55,6% DC, p-value 0.03; IR:57.1% HC vs. 39.7% DC, p-value 0.011)). Humid and dry culture conditions yielded similar rates of BPR (65.0% HC vs 53.0% DC, p-value: 0.11) and live birth rate (44.3% HC vs 34.5% DC, p-value: 0.16). Although there is a tendency towards a 20% of benefit in presence of humidity in both rates, no significance was reached. No differences were found in euploidy between dry and humid groups. When stratifying patients by age, all age groups met the ploidy expected rates in both culture conditions. Humid culture conditions enhance clinical outcomes, particularly in autologous cycles. Donated oocytes may take advantage of their better quality to compensate the detrimental effect of dry ambients. Our study, moreover, demonstrates that humidity does not introduce any bias towards chromosomal alterations or newborn sex. Limitations, reasons for caution This is a retrospective study and should be further confirmed with a prospective randomized study. Sample size should be increased, especially for ploidy Specific humidity values could also be tested. Wider implications of the findings Humid culture conditions may highly improve ART outcomes for particular groups of patients. If tested with stratified groups by age, a specific age group might be especially benefited of humidity, without any bias in sex ratios when best embryo is transferred in fresh cycles. Trial registration number not applicable

P-236 Simulated cohort ranking analysis estimates the number of IVF cycles needed to reach fetal heartbeat with and without artificial intelligence (AI) embryo triage

Abstract Study question What is the impact of AI-based embryo triage on the number of IVF cycles needed to reach fetal heartbeat (FH)? Summary answer Simulated cohort ranking via the AIVF Day-5 AI model demonstrates a 27.5% reduction in the number of IVF cycles needed to achieve FH. What is known already Published reports show FH rates per first-time IVF/single euploid embryo transfer ranging from 26-43% (age &amp;lt;38 yrs). Likewise, the average number of autologous retrieval cycles required for FH is 2.25±0.8, depending on oocyte age and demographic. While conventional embryo morphology ranking is used as a proxy indicator for IVF success, its use is associated with observer variability and manual workflow. This leads to a non-efficient cycle number-per-FH ratio, preventing the clinic’s ability to service more patients. Study design, size, duration A single center database (N = 10,000 embryos) was used to generate 1,288 simulated cohorts reflecting known maternal age/cohort size distributions. Only cohorts containing ≥1 FH+ embryo(s) were included. The model ranked embryos within each cohort by scalar output (1-9.9). The position of the first FH+ embryo within each AI-ranked cohort was calculated and averaged across cohorts to compute number of cycles required to reach FH. Participants/materials, setting, methods Data was stratified into 5 age categories; the prevalence of top/good/fair graded embryos per cohort were included according to their known (%) prevalences per stratified age group. Data was randomized into 1,288 cohorts; positions of the first FH+ embryo in each cohort was calculated (for example, if the 2nd AI-ranked embryo was FH+, a value of 2 was assigned, respectively). Values were averaged and compared to conventional IVF. Main results and the role of chance A mean ± SD of 1.63 ±1.06 cycles was needed to reach the first FH+ embryo with AI cohort ranking (pooled mean across all age groups &amp;lt;38 years) with a mean cohort size N = 7.8 embryos. The relative percent reduction in cycles needed to reach FH when compared to conventional IVF without AI ranking (2.25±0.8; age &amp;lt;38 yrs) was 27.5%. Ranking and electronic recording time for ranking per embryo with/without AI implementation was 186.0 versus 30.9 seconds per embryo, respectively. Relative ranking time reduction was 83%. Limitations, reasons for caution Results were pooled across age groups and not stratified per age. Prospective validation is ongoing to show the influence of demographics/clinical characteristics on AI utility. Wider implications of the findings This study demonstrates the potential of shortening the time to pregnancy by using AI-based quantitative embryo assessment for cohort ranking. Trial registration number Not applicable