Multivariable Mixed-effects Models Research Articles

O79 DAILY URINARY POTASSIUM EXCRETION IS NOT A FIXED PERCENTAGE OF DAILY POTASSIUM INTAKE

Background and Objective: High potassium intake is associated with a lower blood pressure and lower incidence of cardiovascular events. For estimation of potassium intake, the World Health Organization advices to multiply the 24-hour renal potassium excretion by 1.3, considering the substantial fecal potassium loss. We examined the variation in the required conversion factor in healthy volunteers and evaluated the effect of factors associated with tissue cation storage on the renal potassium excretion. Methods: We performed a post-hoc analysis of the Mars long-term sodium balance studies. Healthy male participants consumed a fixed amount of salt (6, 9 and 12 grams/day for >29 days) and potassium (4 grams/day) for 105 (n=4) and 205 days (n=6). All urine was collected in 24-hour aliquots. We calculated the percentage of potassium intake that was excreted in the corresponding 24-hour urine collection during steady-state. A multivariable mixed-effects model was used to assess associations of this percentage with sodium intake, potassium intake, urinary aldosterone, urinary cortisol and urine volume. Results: The median renal potassium excretion was 80% of potassium intake (IQR 65-97%, range 24-304%), corresponding to a conversion factor of 1.25 (IQR 1.03-1.54). Within individual subjects we also observed a marked day-to-day variation in the percentage of renal potassium excretion: the average intraperson width of the IQR was 25%. Sodium intake (figure A), urinary aldosterone (figure B), urinary cortisol (figure C) and urine volume (figure D) were positively associated with the percentage of renal potassium excretion, whereas potassium intake showed a negative association (figure A). A significant positive interaction between the effects of sodium and potassium intake was present (P<0.001). Conclusions: The percentage of dietary potassium that is excreted via urine varies considerably. During steady-state, this percentage is independently affected by sodium intake, potassium intake, urinary aldosterone, urinary cortisol, and urine volume. Our results suggest that the WHO's fixed 1.3 conversion factor may lead to inaccurate estimations of potassium intake.

Characterization of postintensive care syndrome in a prospective cohort of survivors of COVID-19 critical illness: a 12-month follow-up study

PurposeStudies integrating an exhaustive longitudinal long-term follow-up of postintensive care syndrome (PICS) in critically ill COVID-19 survivors are scarce. We aimed to 1) describe PICS-related sequelae over a 12-month period after intensive care unit (ICU) discharge, 2) identify relevant demographic and clinical factors related to PICS, and 3) explore how PICS-related sequelae may influence health-related quality of life (HRQoL) in critically ill COVID-19 survivors.MethodsWe conducted a prospective cohort study in adult critically ill survivors of SARS-CoV-2 infection that did or did not need invasive mechanical ventilation (IMV) during the COVID-19 pandemic in Spain (March 2020 to January 2021). We performed a telemedicine follow-up of PICS-related sequelae (physical/functional, cognitive, and mental health) and HRQoL with five data collection points. We retrospectively collected demographic and clinical data. We used multivariable mixed-effects models for data analysis.ResultsWe included 142 study participants in the final analysis, with a median [interquartile range] age of 61 [53–68] yr; 35% were female and 59% needed IMV. Fatigue/dyspnea, pain, impaired muscle function, psychiatric symptomatology and reduced physical HRQoL were prominent sequelae early after ICU discharge. Over the 12-month follow-up, functionality and fatigue/dyspnea improved progressively, while pain remained stable. We observed slight fluctuations in anxiety symptoms and perception of cognitive deficit, whereas posttraumatic stress disorder (PTSD) and depressive symptoms improved, with a mild rebound at the end of the follow-up. Female sex, younger age, and the need for IMV were risk factors for PICS, while having higher cognitive reserve was a potential protective factor. Physical HRQoL scores showed a general improvement over time, whereas mental HRQoL remained stable. Shorter ICU stay, better functionality, and lower scores for fatigue/dyspnea and pain were associated with better physical HRQoL, while lower scores for anxiety, depression, and PTSD were associated with better mental HRQoL.ConclusionsPostintensive care syndrome was common in COVID-19 critical illness survivors and persisted in a significant proportion of patients one year after ICU discharge, impacting HRQoL. The presence of risk factors for PICS may identify patients who are more likely to develop the condition and who would benefit from more specific and closer follow-up after ICU admission.Study registrationClinicalTrials.gov (NCT04422444); first submitted 9 June 2020.

Evaluating changes in the well-being of older adults during the COVID-19 pandemic: a longitudinal cohort study.

The COVID-19 pandemic affected the lives of older adults. Yet, little is known about changes in well-being among older adults during the pandemic, especially when COVID-19 measures were relaxed. Therefore, we aimed to assess changes in the well-being of older adults during multiple turning points of the pandemic. This longitudinal study included data from Dutch older adults (≥65 years old) participating in the Lifelines COVID-19 cohort. Data consisted of seven questionnaires, administered every 2-4 months between May 2020 and October 2021. The outcomes were quality of life (n = 14682), physical fitness (n = 14761), and feelings of isolation (n = 14611), all graded on a scale from 0 to 10. Changes in well-being were analysed by multivariable linear mixed-effects models. The context of measures was described using the Government Stringency Index. Quality of life and feelings of isolation decreased when measures were tightened and increased when measures were relaxed. For example, when measures relaxed after the first lockdown in May 2020, quality of life increased by 0.23 [95% confidence interval (CI): 0.16-0.29] towards July 2020. Physical fitness decreased by 0.26 [95% CI: 0.15-0.37] during the study period. Differences between subsamples were not found, except for sex in feelings of isolation, which differences diminished after a period of relaxed measures. Changes in quality of life and feelings of isolation improved after periods of stringent COVID-19 measures. Physical fitness did not improve after measures were relaxed, suggesting a possible negative effect of the pandemic on the physical fitness of older adults.

Association of Race and Ethnicity with Prescriptions for Continuous Glucose Monitoring Systems Among a National Sample of Veterans with Diabetes on Insulin Therapy.

Introduction and Objective: Continuous glucose monitoring (CGM) can improve glycemic control in people with diabetes on insulin therapy. We assessed rates of prescriptions for CGM in a national sample of Veterans across subgroups defined by race and ethnicity. Methods: This cross-sectional analysis of data from the U.S. Veterans Health Administration included adults with type 1 or type 2 diabetes on insulin therapy. Main exposures included self-reported race and ethnicity, and primary outcome was the percentage of patients with at least one CGM prescription between January 1, 2020, and December 31, 2021. Association of race and ethnicity categories with CGM prescription was examined using multilevel, multivariable mixed-effects models. Results: Among 368,794 patients on insulin (mean age, 68.5 years; 96% male; 96.8% type 2 diabetes; 0.8% American Indian or Alaska Native, 0.7% Asian, 18.9% Black or African American, 0.9% Native Hawaiian or other Pacific Islander, 70.2% White, 2.8% multiracial, 5.7% with unknown race, and 7.0% Hispanic or Latino ethnicity), 11.2% were prescribed CGM. CGM was prescribed for 10.4% American Indian or Alaska Native, 9.7% Asian, 9.2% Black or African American, 9.3% Native Hawaiian or other Pacific Islander, 11.8% White, 11.8% multiracial, and 10.1% patients with unknown race. CGM was prescribed for 8.3% Hispanic or Latino, 11.4% non-Hispanic, and 11.5% of patients with unknown ethnicity. After accounting for patient-, clinical-, and system-level factors, Black or African American patients had significantly lower odds of CGM prescription compared with White patients (adjusted odds ratio [aOR] 0.62, 95% confidence interval [CI] 0.59-0.64), whereas Hispanic or Latino patients had significantly lower odds compared with non-Hispanic patients (aOR 0.79, 95% CI 0.74-0.84). Findings were consistent across subgroups with clinical indications for CGM use. Conclusions: Among Veterans with diabetes on insulin therapy, there were significant disparities in prescribing of CGM technology by race and ethnicity, which require further study and intervention.

Disease activity of rheumatoid arthritis and kidney function decline: a large prospective registry study

IntroductionChronic kidney disease (CKD) is a common comorbidity of rheumatoid arthritis (RA). The association of longitudinal RA disease activity with long-term kidney function has remained uncertain.MethodWe analysed a multicentre prospective...

Longitudinal analysis of serum urate in prediabetic phase.

Despite the well-established association between prediabetes and hyperuricaemia, knowledge about serum urate (SU) trends during the prediabetic phase is limited. Therefore, we aimed to assess the longitudinal changes of SU in individuals with prediabetes. Individuals with prediabetes, defined by initial haemoglobin A1c (HbA1c) levels between 5.7% and 6.4%, were identified using electronic health records from an academic health system (2007-2022). We required at least one SU test before and after the prediabetes diagnosis. The primary outcome was the longitudinal SU trends during the follow-up period, estimated with a multivariable mixed-effects model. Patients were censored at diabetes onset. Marginal effects of covariates on SU changes were estimated. Subsequent analyses examined SU variations in subgroups stratified by age, sex, body mass index (BMI), HbA1c, estimated glomerular filtration rate (eGFR) and metformin use. Out of 25 526 individuals with prediabetes, 1,521 met the SU cohort requirements, contributing to 6,832 SU observations. At baseline, median age was 63 years and 40% were female. Median values were SU 6.3 mg/dl, HbA1c 5.9% and BMI 30 kg/m2. Median follow-up was 7.4 years. Older age, male sex, greater BMI, and higher HbA1c were significant predictors of increased longitudinal SU levels. Individuals with a BMI ≥30 kg/m2 exhibited higher SU levels compared with those with lower BMI values. Among individuals with prediabetes, several baseline variables were significant predictors of increased SU levels over time. These longitudinal trends in SU, support the potential for early intervention during the prediabetic phase, possibly reducing the risk of gout.

Urinary polycyclic aromatic hydrocarbon metabolites in Chinese pregnant women: Concentrations, variability, predictors, and association with oxidative stress biomarkers

Polycyclic aromatic hydrocarbons (PAHs) are a class of pervasive contaminants having adverse health effects. Urinary monohydroxylated PAHs (OH-PAHs) are commonly employed as biomarkers to estimate PAH exposure levels in humans. However, little is understood about the variability in OH-PAHs among pregnant women across trimesters and their relationship with oxidative stress biomarkers (OSBs). Based on a prospective birth cohort study conducted in Wuhan, China, we selected 644 women who donated (spot) urine samples across different trimesters and measured the urinary concentrations of eight OH-PAHs and three selected OSBs (8-OHG, 8-OHdG, and HNEMA) to explore the relationship between the OH-PAHs and OSBs. Pregnant women were found to be ubiquitously exposed to the PAHs, with detection rates of the OH-PAHs ranging from 86.3% to 100%. 2-Hydroxynaphthalene (2-OH-Nap) had the highest urinary concentrations among the OH-PAHs during the three trimesters (specific gravity-adjusted median values for the first, second, and third trimesters: 1.86, 2.39, and 2.20 ng/mL, respectively). However, low reproducibility of the OH-PAHs was observed across the three trimesters with intraclass correlation coefficients ranged between 0.02 and 0.22. Most urinary OH-PAHs had the highest concentrations at the first trimester and the lowest at the third trimester. Some OH-PAH concentrations were higher in pregnant women with lower educational level [2-hydroxyphenanthrene (2-OH-Phen) and 3-hydroxyphenanthrene (3-OH-Phen)], those who were overweight [2-OH-Nap, 2/3-hydroxyfluorene (2/3-OH-Fluo), 2-OH-Phen, and 4-hydroxyphenanthrene (4-OH-Phen)], those who were unemployed during pregnancy [1-hydroxynaphthalene, 1/9-hydroxyphenanthrene, and 4-OH-Phen], and the samples donated in summer (most OH-PAHs, except for 2-OH-Nap). In multivariable linear mixed-effects model analyses, every OH-PAH was found to be significantly associated with increased levels of the three OSBs. For example, each interquartile range-fold increase in 2/3-OH-Fluo concentration was associated with the largest increase in 8-OHdG (65.4%) and 8-OHG (49.1%), while each interquartile range-fold increase in 3-OH-Phen concentration was associated with the largest increase in HNEMA (76.3%). Weighted quantile sum regression models, which were used to examine the joint effect of OH-PAH mixture on the OSBs, revealed positive associations between the OH-PAH mixture exposure and the OSBs. Specifically, 2/3-OH-Fluo and 2-OH-Nap were the major contributors in the association with oxidative damage of nucleic acids (8-OHdG and 8-OHG), while hydroxyphenanthrenes and 1-hydroxypyrene were the major contributors in the association with oxidative damage of lipid (HNEMA). Further work is required to examine the potential mediating role of oxidative stress in the relationship of adverse health outcomes with elevated PAH exposure among pregnant women.

The Impact of Gardening on Dietary Inflammation: Mixed-Effect Models and Propensity Score Analyses

Gardening has been found to increase vegetable intake and reduce BMI; this suggests that it may improve diets by lowering inflammatory content. The goal of this study goal was to evaluate the effect of gardening on Dietary Inflammatory Index scores. Longitudinal data were collected annually between 2015 and 2018 from adults in low-income, urban neighborhoods of Cleveland and Columbus, Ohio. The authors measured the association between gardening and Dietary Inflammatory Index in the full data set using multivariable mixed-effect models with a random intercept for participant (Model 1; n=409). To further explore potential causation, the author used propensity score analyses in a subset of the data by building a 1-to-1 matched model (Model 2; n=339). Of 409 adults, 30.3% were gardeners with Dietary Inflammatory Index scores ranging from -6.228 to +6.225. Participating in gardening was associated with lower Dietary Inflammatory Index scores in the mixed-effects model (-0.45; 95% CI= -0.85, -0.04; Model 1) and the 1-to-1 matched model (-0.77; 95% CI= -1.40, -0.14; Model 2). The analyses indicate that gardeners had lower Dietary Inflammatory Index scores than nongardeners, implying lower diet-driven inflammation. These findings highlight the potential for a causal relationship between gardening and Dietary Inflammatory Index, which should be confirmed in future studies. If this relationship is validated, strategies to increase gardening may be worth testing as primary prevention tools for diet-driven chronic disease.

Contrasting topologies of synchronous and asynchronous functional brain networks.

We generated asynchronous functional networks (aFNs) using a novel method called optimal causation entropy (oCSE) and compared aFN topology to the correlation-based synchronous functional networks (sFNs) which are commonly used in network neuroscience studies. Functional magnetic resonance imaging (fMRI) time series from 212 participants of the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) study were used to generate aFNs and sFNs. As a demonstration of how aFNs and sFNs can be used in tandem, we used multivariate mixed effects models to determine whether age interacted with node efficiency to influence connection probabilities in the two networks. After adjusting for differences in network density, aFNs had higher global efficiency but lower local efficiency than the sFNs. In the aFNs, nodes with the highest outgoing global efficiency tended to be in the brainstem and orbitofrontal cortex. aFN nodes with the highest incoming global efficiency tended to be members of the Default Mode Network (DMN) in sFNs. Age interacted with node global efficiency in aFNs and node local efficiency in sFNs to influence connection probability. We conclude that the sFN and aFN both offer information about functional brain connectivity which the other type of network does not.

Predictors of long-term memory and network connectivity 10 years after anterior temporal lobe resection.

Anterior temporal lobe resection (ATLR) effectively controls seizures in medically refractory temporal lobe epilepsy but risks significant episodic memory decline. Beyond 1 year postoperatively, the influence of preoperative clinical factors on episodic memory and long-term network plasticity remain underexplored. Ten years post-ATLR, we aimed to determine biomarkers of successful memory network reorganization and establish presurgical features' lasting impact on memory function. Twenty-five ATLR patients (12 left-sided) and 10 healthy controls underwent a memory-encoding functional magnetic resonance imaging paradigm alongside neuropsychometry 10 years postsurgery. Generalized psychophysiological interaction analyses modeled network functional connectivity of words/faces remembered, seeding from the medial temporal lobes (MTLs). Differences in successful memory connectivity were assessed between controls and left/right ATLR. Multivariate regressions and mixed-effect models probed preoperative phenotypes' effects on long-term memory outcomes. Ten years post-ATLR, lower baseline functioning (verbal and performance intelligence quotient) and a focal memory impairment preoperatively predicted worse long-term memory outcomes. Poorer verbal memory was significantly associated with longer epilepsy duration and earlier onset age. Relative to controls, successful word and face encoding involved increased functional connectivity from both or remnant MTL seeds and contralesional parahippocampus/hippocampus after left/right ATLR. Irrespective of surgical laterality, successful memory encoding correlated with increased MTL-seeded connectivity to frontal (bilateral insula, right anterior cingulate), right parahippocampal, and bilateral fusiform gyri. Ten years postsurgery, better memory performance was correlated with contralateral frontal plasticity, which was disrupted with longer epilepsy duration. Our findings underscore the enduring nature of functional network reorganizations to provide long-term cognitive support. Ten years post-ATLR, successful memory formation featured stronger connections near resected areas and contralateral regions. Preoperative network disruption possibly influenced effectiveness of postoperative plasticity. These findings are crucial for enhancing long-term memory prediction and strategies for lasting memory rehabilitation.

Variance due to the examination conditions and factors associated with success in objective structured clinical examinations (OSCEs): first experiences at Paris-Saclay medical school

BackgroundWe aimed to measure the variance due to examination conditions during the first sessions of objective structured clinical examinations (OSCEs) performed at a French medical school and identify factors associated with student success.MethodsWe conducted a retrospective, observational study using data from the first three OSCEs sessions performed at Paris-Saclay medical school in 2021 and 2022. For all sessions (each organized in 5 parallel circuits), we tested a circuit effect using a linear mixed-effects model adjusted for sex and the average academic level of students (according to written tests). Then, we studied the factors associated with student success at one station using a multivariate linear mixed-effects model, including the characteristics of students, assessors, and standardized patients.ResultsThe study included three OSCEs sessions, with 122, 175, and 197 students and a mean (± SD) session score of 13.7(± 1.5)/20, 12.7(± 1.7)/20 and 12.7(± 1.9)/20, respectively. The percentage of variance due to the circuit was 6.5%, 18.2% (statistically significant), and 3.8%, respectively. For all sessions, the student’s average level and station scenario were significantly associated with the score obtained in a station. Still, specific characteristics of assessors or standardized patients were only associated with the student’s score in April 2021 (first session).ConclusionThe percentage of the variance of students’ performance due to the examination conditions was significant in one out of three of the first OSCE sessions performed at Paris-Saclay medical school. This result seems more related to individual behaviors rather than specific characteristics of assessors or standardized patients, highlighting the need to continue training teaching teams.National clinical trial numberNot applicable.

Lemann Index for Assessing Bowel Damage in Crohn’s Disease: A Real-world Study

Abstract Background and Aims The Lemann Index [LI], an endpoint to measure cumulative structural bowel damage in Crohn’s disease [CD], has been recently updated and validated. We applied this to investigate predictors of bowel damage in a real-world cohort. Methods We performed a retrospective study [2008–2022] involving two tertiary referral IBD centres in the USA. Magnetic resonance imaging [MR] or computed tomography [CT] enterographies were reviewed by study radiologists with endoscopy reports by study gastroenterologists, to calculate LI scores. Baseline and follow-up LI scores were calculated. We defined high bowel damage as LI ≥ 2. Factors associated with high LI were identified in patients with ≥ 2 LI scores, using multivariate logistic regression, and then assessed for a change in LI [increase vs no change/decrease], using a multivariate linear mixed-effects model. Results A total of 447 patients with CD had a median first LI of 7 (interquartile range [IQR], 1.25–14.55). Median LI scores were significantly different when categorised by disease duration; 2.0 [IQR, 0.6–5.9] for < 2 years, 2.6 [IQR, 0.6–9.6] for ≥ 2 and < 10 years, and 12.5 [IQR, 6.4–21.5] for ≥ 10 years, with a p < 0.01. Disease duration, presence of perianal disease, elevated C-reactive protein, and Harvey–Bradshaw index, were associated with a high LI at inclusion and increase in LI during follow-up [all p < 0.01]. Conclusions The updated LI quantified cross-sectional and longitudinal cumulative bowel damage in a real-world cohort of patients with CD, with predictors identified for a longitudinal increase in LI. Further studies for prospective validation of LI and identification of multi-omic predictors of bowel damage are needed.

Stochastic behavioral models of bedroom window operation in sub-tropical residential buildings

This study investigates window opening and closing behaviors in residential bedrooms in Hong Kong by examining occupants' habits regarding window operation, window opening and closing behavior, and the influence of environmental and contextual factors. Using self-reported survey data on window opening and closing behavior and outdoor environmental data from an open-source database, univariable and multivariable logistic mixed-effect models were developed to evaluate the impact of various parameters. The findings indicate that outdoor environmental factors have a limited influence on window opening and closing probabilities. Conversely, time of the day was identified as a significant factor, emphasizing the role of occupant habits and preferences in determining these probabilities. Importantly, the study results agreed with the observations that the drivers between window opening and window closing differed, further emphasizing the need for separate modeling. The study highlights the importance of considering environmental and contextual factors when predicting window operation behaviors. This study contributes to our understanding of building occupant behavior and provides valuable insights for building designers and engineers to enhance energy simulations and optimize building performance.

Predicting the individualized risk of human immunodeficiency virus infection among sexually active women in Ethiopia using a nomogram: prediction model development and validation.

Women are more vulnerable to HIV infection due to biological and socioeconomic reasons. Developing a predictive model for these vulnerable populations to estimate individualized risk for HIV infection is relevant for targeted preventive interventions. The objective of the study was to develop and validate a risk prediction model that allows easy estimations of HIV infection risk among sexually active women in Ethiopia. Data from the 2016 Ethiopian Demographic and Health Survey, which comprised 10,253 representative sexually active women, were used for model development. Variables were selected using the least absolute shrinkage and selection operator (LASSO). Variables selected by LASSO were incorporated into the multivariable mixed-effect logistic regression model. Based on the multivariable model, an easy-to-use nomogram was developed to facilitate its applicability. The performance of the nomogram was evaluated using discrimination and calibration abilities, Brier score, sensitivity, and specificity. Internal validation was carried out using the bootstrapping method. The model selected seven predictors of HIV infection, namely, age, education, marital status, sex of the household head, age at first sex, multiple sexual partners during their lifetime, and residence. The nomogram had a discriminatory power of 89.7% (95% CI: 88.0, 91.5) and a calibration p-value of 0.536. In addition, the sensitivity and specificity of the nomogram were 74.1% (95% CI: 68.4, 79.2) and 80.9% (95% CI: 80.2, 81.7), respectively. The internally validated model had a discriminatory ability of 89.4% (95% CI: 87.7, 91.1) and a calibration p-value of 0.195. Sensitivity and specificity after validation were 72.9% (95% CI: 67.2, 78.2) and 80.1% (95% CI: 79.3, 80.9), respectively. A new prediction model that quantifies the individualized risk of HIV infection has been developed in the form of a nomogram and internally validated. It has very good discriminatory power and good calibration ability. This model can facilitate the identification of sexually active women at high risk of HIV infection for targeted preventive measures.

Characterization of the plasma metabolome and lipidome in response to sleeve gastrectomy and gastric bypass surgeries reveals molecular patterns of surgical weight loss

ObjectivesBariatric surgery improves metabolic health, but the underlying mechanisms are not fully understood. We analyzed the effects of two types of bariatric surgery, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), on the plasma metabolome and lipidome. MethodsWe characterized the plasma metabolome (1268 metabolites) and lipidome (953 lipids) pre-operatively and at 3 and 12 months post-operatively in 104 obese adults who were previously recruited to a prospective cohort of bariatric surgery. The metabolomic and lipidomic responses to bariatric surgery over time were analyzed using multivariable linear mixed-effects models. ResultsThere were significant changes in multiple metabolites and lipids, including rapid early changes in amino acid and peptide metabolites, including decreases in branched-chain amino acids (BCAAs), aromatic AAs, alanine and aspartate, and increases in glycine, serine, arginine and citrulline. There were also significant decreases in many triglyceride species, with increases in phosphatidylcholines and phosphatidylethanolamines. There were significant changes in metabolites related to energy metabolism that were apparent only after 12 months. We observed differences by bariatric surgery type in the changes in a small number of primary and secondary bile acids, including glycohyocholate and glyco-beta-muricholate. ConclusionsOur findings highlight the comprehensive changes in metabolites and lipids that occur over the 12 months following bariatric surgery. While both SG and RYGB caused profound changes in the metabolome and lipidome, RYGB was characterized by greater increases in bile acids following surgery.

Association of amisulpride and recovery room length of stay among patients with postoperative nausea and vomiting following outpatient surgery

Study objectivePostoperative nausea and vomiting (PONV) is a common sequela of surgery in patients undergoing general anesthesia. Amisulpride has shown promise in its ability to treat PONV. The objective of this study was to determine if amisulpride is associated with significant changes in PACU efficiency within a fast-paced ambulatory surgery center. MethodsThis was a retrospective cohort study of 816 patients at a single ambulatory surgery center who experienced PONV between 2018 and 2023. The two cohorts analyzed were patients who did or did not have amisulpride among their anti-emetic regimens in the PACU during two distinct time periods (before and after amisulpride was introduced). The primary outcome of the study was PACU length of stay. Both unmatched analysis and a linear multivariable mixed-effects model fit by restricted maximum likelihood (random effect being surgical procedure) were used to analyze the association between amisulpride and PACU length of stay. We performed segmented regression to account for cohorts occurring during two time periods. ResultsUnmatched univariate analysis revealed no significant difference in PACU length of stay (minutes) between the amisulpride and no amisulpride cohorts (115 min vs 119 min, respectively; P = 0.07). However, when addressing confounders by means of the mixed-effects multivariable segmented regression, the amisulpride cohort was associated with a statistically significant reduction in PACU length of stay by 26.1 min (P < 0.001). ConclusionsThis study demonstrated that amisulpride was associated with a significant decrease in PACU length of stay among patients with PONV in a single outpatient surgery center. The downstream cost-savings and operational efficiency gained from this drug's implementation may serve as a useful lens through which this drug's widespread implementation may further be rationalized.

Anesthesia Techniques for Vitreoretinal Surgery in the United States: A Report from the Multicenter Perioperative Outcomes Group Research Consortium

PurposeTo explore the patterns of anesthesia use and their determinants during vitreoretinal (VR) surgeries in academic and community hospitals across the US, using data from the Multicenter Perioperative Outcomes Group (MPOG). DesignA retrospective, multicenter, cohort study. MethodsWe queried the MPOG database of 107,066 patients undergoing VR surgeries. Patients (≥18 yrs.) undergoing VR surgery with monitored anesthesia care (MAC) or general anesthesia (GA) from January 1, 2015, to December 31, 2021 were included. Patient-level, case-based, and institutional-level covariates were collected. We performed multivariable mixed-effects models to determine predictors of anesthesia type use. The primary outcome was the type of anesthesia (MAC or GA) used during VR surgeries. As a secondary outcome, MAC cases were further classified based on the additional use of sedation into MAC with or without sedation. ResultsWe found that 67.45% of VR surgery cases received MAC, and 73.63% of institutions administered MAC to more than half of cases. Random effect modeling revealed that 47.76% of the variation in MAC use was attributed to institutions. A trend toward increased use of MAC with increasing age was observed. Patients diagnosed with chronic pulmonary disease, liver disease, or a history of drug abuse were less likely to receive MAC. Conversely, we found that patients with reported alcohol abuse disorder, diabetes with complications, and those with American Society of Anesthesiologists (ASA) physical status of 4 (vs. 1, 2, or 3) were more likely to use MAC. Compared to non-complex VR surgeries, there was a notably decreased likelihood of MAC use in complex PPV (P = 0.004), PPV + scleral buckle (SB) for retinal detachment (P < 0.0001), and primary SB surgery (P < 0.0001). ConclusionsApproximately 2/3 of VR anesthesia is under MAC, but GA is still preferred for SBs, complex vitrectomy, and younger patients. We show that large interinstitutional variation for using MAC in practice exists.

Resting state EEG relates to short- and long-term cognitive functioning after cardiac arrest

BackgroundApproximately half of cardiac arrest survivors have persistent cognitive impairment. Guidelines recommend early screening to identify patients at risk for cognitive impairment, but there is no consensus on the best screening method. We aimed to identify quantitative EEG measures relating with short- and long-term cognitive function after cardiac arrest for potential to cognitive outcome prediction. MethodsWe analyzed data from a prospective longitudinal multicenter cohort study designed to develop a prediction model for cognitive outcome after cardiac arrest. For the current analysis, we used twenty-minute EEG registrations from 80 patients around one week after cardiac arrest. We calculated power spectral density, normalized alpha-to-theta ratio (nATR), peak frequency, and center of gravity (CoG) of this peak frequency. We related these with global cognitive functioning (scores on the Montreal Cognitive Assessment (MoCA)) at one week, three and twelve months follow-up with multivariate mixed effect models, and with performance on standard neuropsychological examination at twelve months using Pearson correlation coefficients. ResultsEach individual EEG parameter related to MoCA at one week (βnATR = 7.36; P < 0.01; βpeak frequency = 1.73, P < 0.01; βCoG = -9.88, P < 0.01). The nATR also related with the MoCA at three months ((βnATR = 2.49; P 0.01). No EEG metrics significantly related to the MoCA score at twelve months. nATR and peak frequency related with memory performance at twelve months. Results were consistent in sensitivity analyses. ConclusionEarly resting-state EEG parameters relate with short-term global cognitive functioning and with memory function at one year after cardiac arrest. Additional predictive values in multimodal prediction models need further study.

#1429 Daily urinary potassium excretion is not a fixed percentage of daily potassium intake

Abstract Background and Aims High potassium intake is associated with a lower blood pressure and lower incidence of chronic kidney disease. Since a significant amount of potassium is lost via stool, the World Health Organization advices to multiply 24-hour renal potassium excretion by 1.3 for estimation of dietary intake. We analyzed whether this 1.3 factor for potassium intake varies in healthy volunteers and evaluated whether factors associated with tissue cation storage, namely sodium intake, aldosterone, cortisol and urine volume, affect the renal potassium excretion. Method We performed a post-hoc analysis of the long-term sodium balance studies Mars105 and Mars520. Ten healthy male participants consumed a fixed amount of salt (6, 9 and 12 grams/day for &amp;gt;29 days) and potassium (4 grams/day) for 105 (n = 4) and 205 days (n = 6). During the entire study period all urine was collected in 24-hour aliquots. We calculated the percentage of potassium intake that was excreted in the corresponding 24-hour urine collection during steady-state. We assessed whether this percentage was associated with sodium intake, potassium intake, urinary aldosterone, urinary cortisol and urine volume using a multivariable mixed-effects model. Results Overall, the median renal potassium excretion was 80% of potassium intake (IQR 65-97%; range 24-304%). This corresponds to a conversion factor of 1.25 (IQR 1.03-1.54). Within individual subjects we also observed a marked day-to-day variation in the percentage of renal potassium excretion: the average intraperson width of the IQR was 25%. A higher sodium intake was associated with an increased percentage of renal potassium excretion, whereas a higher potassium intake was associated with a decreased percentage of renal potassium excretion. A significant positive interaction between the effects of sodium and potassium intake was present (P &amp;lt; .001; Fig. A). Furthermore, urinary aldosterone (Fig. B), urinary cortisol (Fig. C) and urine volume (Fig. D) were positively associated with the percentage of renal potassium excretion. Conclusion The percentage of consumed potassium that is excreted via urine shows considerable intra- and inter-subject variability. During steady-state this percentage is independently affected by sodium intake, potassium intake, urinary aldosterone, urinary cortisol, and urine volume. Our results suggest that the WHO's fixed 1.3 conversion factor may lead to inaccurate estimations of potassium intake.

Risk factors for gingival invagination: A retrospective study.

This study aimed to identify the risk factors for gingival invagination during orthodontic treatment after premolar extraction. The medical records of 135 patients who had undergone interdental space closure after premolar extraction were collected, and cone beam computed tomography was performed to determine the presence of gingival invagination. The risk factors were examined using mixed-effects models and generalized propensity score weighting (GPSW) to develop a predictive model. Univariate analysis revealed that the extraction site, buccal bone thickness 4 mm apical to the cemento-enamel junction (MB1), mid-root buccal bone thickness (MB2) and vertical skeletal relationships were related to gingival invagination (p < .05). Furthermore, a subsequent multivariable mixed-effects model analysis indicated a significantly increased risk of gingival invagination at MB1 < 1 mm (p < .001; odds ratio [ORMB1≤0.5mm] = 29.304; 95% confidence interval [CI]: 8.986-93.807; OR0.5<MB1<1mm = 22.309; 95% CI: 9.890-50.320). Row mixing model analysis performed after balancing covariates using GPSW showed that MB1 and vertical skeletal relationships were associated with gingival invagination (p < .05) with an increase in ORs. Therefore, in addition to MB1, the risk of gingival invagination is higher in hyperdivergent and normodivergent patients. During the establishment and internal validation of the predictive model, the area under the curve for all three models exceeded 0.7. The risk of gingival invagination is higher in patients with MB1 < 1 mm and in normodivergent or hyperdivergent patients.