muFlowReacT: A Library to Solve Multiphase Multicomponent Reactive Transport on Unstructured Meshes

In this paper we present a new reactive transport code for the efficient simulation of groundwater quality problems. The new code couples the two previously existing tools OpenFoam and PhreeqcRM. The major objective of the development was to transfer and expand the capabilities of the MODFLOW/MT3DMS-family of codes, especially their outstanding ability to suppress numerical dispersion, to a versatile and computationally efficient code for unstructured grids. Owing to the numerous, previously existing transport solvers contained in OpenFoam, the newly developed code achieves this objective and provides a solid basis for future expansions of the code capabilities. The flexibility of the OpenFoam framework is illustrated by the addition of diffusional processes for gaseous compounds in the unsaturated zone and the advection of gases (multiphase transport). The code capabilities and accuracy are illustrated through several examples: (1) a simple 2D case for conservative solute transport under saturated conditions, (2) a gas diffusion case with reactions in the unsaturated zone, (3) a hydrogeologically complex 3D reactive transport problem, and finally (4) the injection of CO2 into a deep aquifer with acidification being buffered by carbonate minerals.

How CPC+ supported patient care during the COVID-19 pandemic: Lessons for alternative payment models

BACKGROUND

A growing literature documents how primary care practices adapted to the COVID-19 pandemic. We examine a topic that has received less attention-how participants in an advanced alternative payment model perceive the model influenced their ability to meet patients' care needs during the pandemic.

METHODS

Analysis of closed- and open-ended questions from a 2021 survey of 2496 practices participating in the Comprehensive Primary Care Plus (CPC+) model (92% response rate) and a 2021 survey of 993 randomly selected primary care physicians from these practices (55% response rate). Both surveys asked whether respondents agreed or disagreed that they or their practice was "better positioned to meet patients' care needs during the coronavirus pandemic" because of participation in CPC+. Both also included an open-ended question about CPC+'s effects.

RESULTS

Half of practices and one-third of physicians agreed or strongly agreed that participating in CPC+ better positioned them to meet patients' care needs during the pandemic. One in 10 practices and 2 in 10 physicians, disagreed or strongly disagreed, while 4 in 10 practices and slightly more than half of physicians neither agreed nor disagreed (or, for physicians, didn't know). The most commonly identified CPC+ activities that facilitated meeting patient care needs related to practices' work on care management (e.g., risk stratification), access (e.g., telehealth), payment outside of fee-for-service (FFS), and staffing (e.g., supporting care managers).

CONCLUSIONS

Most CPC+ practices and physicians were positive or neutral about participating in CPC+ in the context of COVID-19, indicating more benefit than risk to payment alternatives to FFS.

Hospital outpatient department billing is a poor indicator of primary care practice integration with hospital systems

OBJECTIVE

To test the reliability of Medicare claims in measuring vertical integration. We assess the accuracy of a commonly used measure of integration, primary care physician (PCP) practices billing Medicare as a hospital outpatient department (HOPD) in claims.

DATA SOURCES AND STUDY SETTING

Medicare fee-for-service claims, IQVIA, and CPC+ practice surveys for this study.

STUDY DESIGN

We compare measures of integration from Medicare claims to self-reported indicators of integration from IQVIA and a survey of CPC+ participating practice sites.

DATA COLLECTION/EXTRACTION METHODS

We measure integration by using site-of-service billing in the 100% sample of Medicare Carrier claims from 2017-2020. In the IQVIA SK&A (2017-2018), OneKey (2019-2020), and practice survey data (2017-2019), we use self-reported responses to measure integration.

PRINCIPAL FINDINGS

We find that currently most PCP practices sites that report themselves as being integrated with a health system do not bill as an HOPD. In 2017, 11% of CPC+ practices were identified as being vertically integrated in claims, while the equivalent numbers in SK&A and surveys were 52% and 54% integration, respectively. A t-test found that both datasets significantly differed from claims (Survey: 41.3%-45.1%; SK&A: 45.3%-51.1%); this gap persists in 2018-2019.

CONCLUSION

Measuring physician-hospital vertical integration accurately is integral to determining consolidation. The overwhelming majority of PCP practice sites not billing as an HOPD may reflect Medicare regulatory changes that have reduced the financial incentives for doing so. These findings have implications for researchers that study the growth in PCP-hospital integration in health care markets.

Incorporating health IT into primary care transformation

OBJECTIVES

To understand the role of health information technology (IT) vendors and health IT functionality in supporting advanced primary care.

STUDY DESIGN

We synthesized multiple rounds of surveys and interviews (2017-2022) from a mixed-methods evaluation of Comprehensive Primary Care Plus (CPC+), a multipayer model developed by CMS. CPC+ was the first federal advanced primary care reform effort that formalized health IT vendors' roles in supporting health IT implementation and specified detailed health IT requirements for practices.

METHODS

We conducted content analysis to identify cross-cutting themes related to health IT for both practices and vendors, comparing similarities and differences across participants and (when possible) over time.

RESULTS

Vendors and practices reported advances in registries and dashboards for improved information management within the practice as well as strengthened relationships between vendors and practices that supported health IT implementation. However, CPC+ practices noted several gaps or challenges using existing functionalities, and both vendors and practices reported broader challenges for more transformative health IT change, particularly the lack of interoperable health information exchange needed to support care management and care coordination. Key factors constraining vendors' investment in further advances included long product development schedules, making it difficult to respond to rapidly evolving model requirements. Vendors also shared that CPC+ practices represented a small fraction of their client base, so investing in developing new functionality was not strategic unless it was more broadly relevant outside CPC+.

CONCLUSIONS

Continued collaboration among health IT vendors, practices, policy makers, and payers could support continued technological improvements, particularly related to information exchange and communication. Aligning requirements more closely with other federal and private models could also help mitigate the risk for vendors.

Quantum Monte Carlo Method in the Steady State

We present a numerically exact steady-state inchworm Monte Carlo method for nonequilibrium quantum impurity models. Rather than propagating an initial state to long times, the method is directly formulated in the steady state. This eliminates any need to traverse the transient dynamics and grants access to a much larger range of parameter regimes at vastly reduced computational costs. We benchmark the method on equilibrium Green's functions of quantum dots in the noninteracting limit and in the unitary limit of the Kondo regime. We then consider correlated materials described with dynamical mean field theory and driven away from equilibrium by a bias voltage. We show that the response of a correlated material to a bias voltage differs qualitatively from the splitting of the Kondo resonance observed in bias-driven quantum dots.

Association between abnormal fetal head growth and autism spectrum disorder

Introduction

Despite evidence for the prenatal onset of abnormal head growth in ASD children, studies on fetal ultrasound data in ASD are limited and controversial.

Objectives

To understand whether people with ASD have abnormal head growth during gestation

Methods

A longitudinal matched case-sibling-control study on prenatal ultrasound biometric measures of ASD children was conducted. Children with ASD were matched to two control groups: (1) typically developed sibling (TDS) and (2) typically developed population (TDP). The cohort comprised 528 children (72.7% males): 174 ASD, 178 TDS, and 176 TDP.

Results

Second-trimester ASD and TDS fetuses had significantly smaller biparietal diameter (BPD) than TDP fetuses (aOR_zBPD=0.685, 95%CI=0.527-0.890 and aOR_zBPD=0.587, 95%CI=0.459-0.751, respectively). However, these differences became statistically indistinguishable in the third trimester. Head biometric measures were associated with the sex of the fetus, with males having larger heads than females within and across groups. A linear mixed-effect model assessing the effects of sex and group assignment on fetal longitudinal head growth indicated faster BPD growth in TDS vs both ASD and TDP in males (β=0.084 and β=0.100 respectively; p<0.001) but not in females, suggesting an ASD–sex interaction in head growth during gestation. Fetal head shape showed sex-specific characteristics, and head growth was inversely correlated with ASD severity in males and females, thus further supporting the sex effect on the association between fetal head growth and ASD.

Conclusions

Our findings suggest that abnormal fetal head growth is a familial trait of ASD, which is modulated by sex and is associated with the severity of the disorder.

Disclosure

No significant relationships.

Metrics for assessing physician activity using electronic health record log data

Electronic health record (EHR) log data have shown promise in measuring physician time spent on clinical activities, contributing to deeper understanding and further optimization of the clinical environment. In this article, we propose 7 core measures of EHR use that reflect multiple dimensions of practice efficiency: total EHR time, work outside of work, time on documentation, time on prescriptions, inbox time, teamwork for orders, and an aspirational measure for the amount of undivided attention patients receive from their physicians during an encounter, undivided attention. We also illustrate sample use cases for these measures for multiple stakeholders. Finally, standardization of EHR log data measure specifications, as outlined here, will foster cross-study synthesis and comparative research.

The impact of a nationwide hands-on workshop on the diagnostic rates and management of obstetrical anal sphincter Injuries in Israel

AIM

The aim was to evaluate the influence of a half day, hands-on, workshop on the detection and repair of obstetric anal sphincter injuries (OASIs).

METHOD

Starting in February 2011, hands-on workshops for the diagnosis and repair of OASIs were delivered by trained urogynaecologists in departments of tertiary medical centres in Israel. The structure of the hands-on workshop resembles the workshop organized at the International Urogynecological Association annual conferences. Participants included medical staff, midwives and surgical residents from each medical centre. We collected data regarding the rate of OASIs, 1 year before and 1 year following the workshop, in 11 medical centres. The study population was composed of parturients with the following inclusion criteria: singleton pregnancy, vertex presentation and vaginal delivery. Pre-viable preterm gestations (< 24 weeks), birth weight < 500 g, stillborn, and those with major congenital anomalies, multifoetal pregnancies, breech presentations and caesarean deliveries were excluded from the analysis.

RESULTS

In the reviewed centres, 70 663 (49.3%) women delivered prior to the workshop (pre-workshop group) and 72 616 (50.7%) women delivered following the workshop (post-workshop group). Third- or fourth-degree perineal tears occurred in 248 women (0.35%) before the workshop, and in 328 (0.45%) following the workshop, a significant increase of 28.7% (P = 0.002). The increase in diagnosis was significant also in women with third-degree tears alone, 226 women (0.32%) before the workshop and 298 (0.41%) following the workshop, an increase of 28.3% (P = 0.005).

CONCLUSION

The detection rate of OASIs has significantly increased following the hands-on workshop. The implementation of such programmes is crucial for increasing awareness and detection rates of OASI following vaginal deliveries.

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

High Pressure Liquid Chromatographic Determination of Monoand Disaccharides in Presweetened Cereals: Collaborative Study

A collaborative study was conducted using a modified AOAC method (sugars in chocolate) for the determination of fructose, glucose, sucrose, and maltose in presweetened cereals by high pressure liquid chromatography (HPLC). Eight samples consisting of 6 products were analyzed in duplicate by the HPLC method and the AOAC Lane-Eynon method. The AOAC method was modified to use water-alcohol (1 + 1) and Sep-Pak C18 cartridges for sample cleanup. The HPLC results indicate precision comparable to the Lane-Eynon method and the chocolate method. The modified HPLC method has been adopted official first action.

Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

4291Six-month outcomes from the multicenter, prospective study with the novel PASCAL transcatheter valve repair system for patients with mitral regurgitation in the CLASP study

Background

Severe mitral regurgitation may lead to an impaired prognosis if left untreated. Transcatheter treatment options have emerged as an alternative to surgery and an adjunct to medical therapy. We report the six-month results of the PASCAL transcatheter valve repair system in treating patients with mitral regurgitation enrolled in the multicenter, prospective, single arm CLASP study.

Methods

The PASCAL Transcatheter Valve Repair System is a leaflet repair therapy that uses clasps and paddles to place a woven Nitinol spacer between the native valve leaflets to fill the regurgitant orifice via a transseptal approach. Eligible patients had clinically significant MR despite optimal medical therapy and were deemed candidates for transcatheter mitral repair by the local Heart Team. Safety, performance, and clinical outcomes were prospectively assessed at baseline, discharge, 30 days, and 6 months post-procedure. All major adverse events (MAE) were adjudicated by an independent clinical events committee and echocardiographic images were assessed by a core lab. The MAE rate was the primary safety endpoint, defined as the composite of cardiovascular mortality, stroke, MI, new need for renal replacement therapy, severe bleeding, and re-intervention for study device-related complications.

Results

Between June 2017 and September 2018, 62 patients were enrolled at 14 sites worldwide for transcatheter mitral valve reconstruction using the PASCAL system. The mean age was 76.5 years (62.9% male). All patients had MR grade ≥3+, with 59% functional, 34% degenerative, and 7% mixed etiology, and 51.6% of patients were in NYHA Class III/IV. Successful implantation of the PASCAL device was achieved in 95% of patients. At discharge, 95% of patients had MR grade ≤2+ with 81% grade ≤1+. There was one cardiovascular mortality and the MAE rate was 4.8%. At 30-day follow-up, paired analyses shows that 98% of patients had MR grade ≤2+ with 81% grade ≤1+ and 88% were in NYHA Class I/II (p<0.0001). The 6MWD improved by 38.9 m (p=0.0015) and was accompanied by average improvements in KCCQ and EQ5D scores by 14.1 points (p<0.0001) and 8.3 points (p=0.0028), respectively. The six-month data will be available for presentation.

Conclusions

In this early device experience, the PASCAL transcatheter valve repair system showed an acceptable safety profile and performed as intended in treating patients with mitral regurgitation. The PASCAL device resulted in significant MR grade reduction, which was associated with clinically and statistically significant improvements in functional status, exercise capacity, and quality of life. Continued follow-up is warranted to validate these initial promising results.

Acknowledgement/Funding

Edwards Lifesciences

1445Physical activity and long-term mortality risk in Israeli older adults with and without cardiovascular disease

Background

Physical activity (PA) is a known protective factor among both general population and cardiovascular disease (CVD) patients. Yet, only a few cohort studies assessed the role of PA among older adult populations, characterized by high CVD prevalence rates.

Objectives

To evaluate the association between PA levels and all-cause mortality among Israeli older adults, and to assess whether it differs by baseline CVD status.

Methods

Participants were drawn from the National Health and Nutrition Survey of Older Adults Aged 65+ (“Mabat-Zahav”), conducted by the Israel Center for Disease Control between July 2005 and December 2006. Clinical, behavioral, and psychosocial data were collected via interview at study entry; a detailed PA questionnaire was also administered, through which participants were classified as sufficiently-active, insufficiently-active, and inactive, according to the American College of Sports Medicine classification. Mortality data (last follow-up, December 2016) were obtained from the Israeli Ministry of Health. Inverse probability weighted Cox proportional hazards models, based on propensity score, were constructed to assess the adjusted association between PA categories and mortality.

Results

Of the 1799 participants (mean [SD] age, 74.6 [6.2] years; 647 [36%] with a history of CVD), 559 (31%) were sufficiently-active, 506 (28%) were insufficiently-active and 734 (41%) were inactive. During a mean follow-up period of 9.0 years, 684 participants (38%) died. PA and mortality demonstrated an inverse dose-response relationship in both CVD and non-CVD groups, with no CVD-by-PA interaction detected on multiplicative-scale (P=0.70) or additive-scale (P=0.58). Notably, inactive non-CVD subjects had comparable risk to CVD patients who were sufficiently active (Figure).

Physical activity and mortality

Conclusions

In a nationally-based cohort of subjects aged 65 years and over, PA was inversely associated with mortality risk. CVD patients who preformed sufficient PA had a comparable mortality risk to inactive subjects free of CVD. These findings illustrate the importance of PA in the older adult population.

Venous thrombosis during olanzapine treatment: a complex association

Olanzapine, a second generation antipsychotic, has previously been associated with an increased risk of venous thromboembolism (VTE). In this mini-review we describe a case of a thirty-year-old schizophrenic patient who was diagnosed with a deep venous thrombosis (DVT) six months after starting olanzapine therapy, as well as seventeen other VTE cases in patients using olanzapine reported to the Netherlands Pharmacovigilance Centre Lareb. In 14 of these reports, patients had reported additional risk factors for VTE. We found disproportionate Reporting Odds Ratios (RORs) in the global database VigiBase for olanzapine and the reactions deep vein thrombosis (ROR of 1.38 with a 95% CI (Confidence Interval) of 1.22-1.57) and pulmonary embolism (ROR of 1.99 with a 95% CI of 1.81-2.19). The mechanism behind the association of olanzapine with VTE could be explained by two risk factors, substantial weight gain and lethargy, both common side effects of olanzapine. So far, a direct effect of olanzapine on platelet aggregation or coagulation has not been found. Schizophrenic patients are more likely to have diagnostic delay in the diagnosis of VTE, as symptoms such as lethargy and impaired pain perception result in diminished pain perception and pain expression, while they are at increased risk of developing VTE. Currently no validated risk score is available for detection of psychiatric patients who might benefit from pharmacologic VTE prophylaxis. In patients developing a VTE while being treated with olanzapine, discontinuation of olanzapine could be considered based on the individual risk profile, control of psychotic symptoms and antipsychotic treatment options.

Clinical Data Mining: a Review

Objective Clinical data mining is the application of data mining techniques using clinical data. We review the literature in order to provide a general overview by identifying the status-of-practice and the challenges ahead.

Methods The nine data mining steps proposed by Fayyad in 1996 [4] were used as the main themes of the review. MEDLINE was used as primary source and 84 papers were retained based on our inclusion criteria.

Results Clinical data mining has three objectives: understanding the clinical data, assist healthcare professionals, and develop a data analysis methodology suitable for medical data. Classification is the most frequently used data mining function with a predominance of the implementation of Bayesian classifiers, neural networks, and SVMs (Support Vector Machines). A myriad of quantitative performance measures were proposed with a predominance of accuracy, sensitivity, specificity, and ROC curves. The latter are usually associated with qualitative evaluation.

Conclusion Clinical data mining respects its commitment to extracting new and previously unknown knowledge from clinical databases. More efforts are still needed to obtain a wider acceptance from the healthcare professionals and for generalization of the knowledge and reproducibility of its extraction process: better description of variables, systematic report of algorithm parameters including the method to obtain them, use of easy-to-understand models and comparisons of the efficiency of clinical data mining with traditional statistical analyses. More and more data will be available for data miners and they have to develop new methodologies and infrastructures to analyze the increasingly complex medical data.

Uremic Toxicity: Present State of the Art

The uremic syndrome is a complex mixture of organ dysfunctions, which is attributed to the retention of a myriad of compounds that under normal condition are excreted by the healthy kidneys (uremic toxins). In the area of identification and characterization of uremic toxins and in the knowledge of their pathophysiologic importance, major steps forward have been made during recent years. The present article is a review of several of these steps, especially in the area of information about the compounds that could play a role in the development of cardiovascular complications. It is written by those members of the Uremic Toxins Group, which has been created by the European Society for Artificial Organs (ESAO). Each of the 16 authors has written a state of the art in his/her major area of interest.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents

OBJECTIVES

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period.

METHODS

Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification.

RESULTS

1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10⁵ for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10⁵ (+126%; P<0.001) and for UC, from 1.6 to 4.1/10⁵ (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC.

CONCLUSIONS

In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.