Causal Impact of the Hospital Readmissions Reduction Program on Hospital Readmissions and Mortality

Estimating causal effects of the Hospital Readmissions Reduction Program (HRRP), part of the Affordable Care Act, has been very controversial. Associational studies have demonstrated decreases in hospital readmissions, consistent with the intent of the program, although analyses with different data sources and methods have differed in estimating effects on patient mortality. To address these issues, we define the estimands of interest in the context of potential outcomes, we formalize a Bayesian structural time-series model for causal inference, and discuss the necessary assumptions for estimation of effects using observed data. The method is used to estimate the effect of the passage of HRRP on both the 30-day readmissions and 30-day mortality. We show that for acute myocardial infarction and congestive heart failure, HRRP caused reduction in readmissions while it had no statistically significant effect on mortality. However, for pneumonia, HRRP had no statistically significant effect on readmissions but caused an increase in mortality.Comment: 10 pages, 1 figure, 2 table

DETC2006-99292 LEA: SOFTWARE SYSTEM FOR MULTIMEDIA AND VIRTUAL-REALITY WEB-BASED EDUCATION AND TRAINING

ABSTRACT LEA (Learning Environments Agent) is a web-based software system for advanced multimedia and virtual-reality education and training. LEA consists of three fully integrated components: (1) unstructured knowledge-base engine for lecture delivery; (2) structured hierarchical process knowledgebase engine for step-by-step process training; and (3) hierarchical rule-based expert system for natural-language understanding. In addition, LEA interfaces with components which provide the following capabilities: 3D near photorealistic interactive virtual environments; 2D animated multimedia; near-natural synthesized text-to-speech, speech recognition, near-photorealistic animated virtual humans to act as instructors and assistants; and socket-based network communication. LEA provides the following education and training functions: multimedia lecture delivery; virtual-reality based step-by-step process training; and testing capability. LEA can deliver compelling multimedia lectures and content in science fields (such as engineering, physics, math, and chemistry) that include synchronized: animated 2D and 3D graphics, speech, and written/highlighted text. In addition, it can be used to deliver step-by-step process training in a compelling near-photorealistic 3D virtual environment. In this paper the LEA system is presented along with typical educational and training applications

Electronic Structures of Quantum Dots and the Ultimate Resolution of Integers

The orbital angular momentum L as an integer can be ultimately factorized as a product of prime numbers. We show here a close relation between the resolution of L and the classification of quantum states of an N-electron 2-dimensional system. In this scheme, the states are in essence classified into different types according to the m(k)-accessibility, namely the ability to get access to symmetric geometric configurations. The m(k)-accessibility is an universal concept underlying all kinds of 2-dimensional systems with a center. Numerical calculations have been performed to reveal the electronic structures of the states of the dots with 9 and 19 electrons,respectively. This paper supports the Laughlin wave finction and the composite fermion model from the aspect of symmetry.Comment: Two figure

Novel salted anionic-cationic polymethacrylate polymer blends for sustained release of acidic and basic drugs

Background: Since a unique matrix tablet formulation that independently controls the release of various drug types is in a great demand, the objective of this research was to develop a sustained release matrix tablet as a universal dosage form using a binary mixture of the salt forms of Eudragit polymers rather than their interpolyelectrolyte complexes. Methods: Tablets were prepared by wet granulation and compressed at different compression forces, depending on drug type. Dissolution tests were conducted using USP XXII rotating paddle apparatus at 50 rpm at 37°C in consecutive pH stages. Results: Tablets containing Ibuprofen (IB) as a model acidic drug and Metronidazole (MD) as a model basic drug showed controlled/sustained release behavior. For IB tablets containing 80% Ibuprofen and 5% (w/w) polymeric combination; the time for 50% of the drug release was about 24 hours compared to 8.5 hours for plain tablets containing 80% IB. In case of MD, the drug release extended to about 7 hours for tablets containing 80% MD and 5% (w/w) polymeric combination, compared to about 1 hour for plain tablets containing 80% MD. In terms of extending the release of medications, the dissolution profiles of the tablets containing polymeric salts forms were found to be statistically superior to tablets prepared by direct compression of the polymers in their powdered base forms, and superior to tablets containing the same polymers granulated using isopropyl alcohol. Conclusion: The findings indicated the significance of combining the polymers in their salt forms in controlling the release of various drug types from matrices

Implications of the PEGASUS-TIMI 54 Trial for US Clinical Practice

Objectives This study aims to determine the proportion of real-world patients with myocardial infarction (MI) who would have been eligible for the PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients with Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis in Myocardial Infarction 54) trial, to characterise their current use of P2Y12 inhibitors and to explore the estimated costs and ischaemic event consequences of increasing P2Y12 inhibitor use among these patients. Methods In the US national ACTION Registry–GWTG (Acute Coronary Treatment and Intervention Outcomes Network Registry–Get With The Guidelines), we identified 273 328 patients with MI and determined the proportion that would have met the eligibility criteria for the PEGASUS trial. We described longitudinal P2Y12 inhibitor use among patients eligible for PEGASUS and estimated the cost and ischaemic consequences of increasing P2Y12 use among eligible patients. Results A total of 112 222 (41.1%) patients with MI in ACTION Registry–GWTG met eligibility for the PEGASUS trial. Among 83 871 eligible patients with pharmacy claims data, 23 042 (27.5%) were on a P2Y12 inhibitor at 1 year, 9661 (11.5%) at 2 years and 5246 (6.3%) at 3 years, with the majority (79.2%) of these patients on clopidogrel. The use of ticagrelor in eligible patients not yet on a P2Y12 inhibitor at 1 year post-MI would cost an estimated US$885 000 per MI, stroke or cardiovascular death averted over a 3-year time horizon, while the use of clopidogrel would cost an estimated US$19 800 per ischaemic event averted. Conclusion In contemporary clinical practice, a minority of patients are on a P2Y12 inhibitor beyond 1-year post-MI. Applying PEGASUS trial findings to clinical practice would result in a large increase in P2Y12 inhibitor use, with a cost per ischaemic event averted that is strongly influenced by the choice of therapy

Investigation the generalized extreme value under liner distribution parameters for progressive type-Ⅱ censoring by using optimization algorithms

Several random phenomena have been modeled by using extreme value distributions. Based on progressive type-Ⅱ censored data with three different distributions (i.e., fixed, discrete uniform, and binomial random removal), the statistical inference of the generalized extreme value distribution under liner normalization (GEVL distribution) parameters is investigated in this study. Since there is no analytical solution, determining the maximum likelihood parameters for the GEVL distribution is considered to be a problem. Standard numerical methods are frequently insufficient for this dilemma, requiring the use of artificial intelligence algorithms to address this difficulty. Here, nonlinear minimization and a genetic algorithm have been used to tackle that problem. In addition, Lindley approximation and Monte Carlo estimation were implemented via Metropolis-Hastings algorithms to carry out the Bayesian point estimation based on both the squared error loss function and LINEX loss functions. Moreover, the highest posterior density intervals were applied. The proposed theoretical inference techniques have been applied in a numerical simulation and a real-life example

Trends in Diagnosis Related Groups for inpatient admissions and associated changes in payment from 2012 to 2016

Importance: Hospitals are reimbursed based on Diagnosis Related Groups (DRGs), which are defined, in part, by patients having 1 or more complications or comorbidities within a given DRG family. Hospitals have made substantial investment in efforts to document these complications and comorbidities. Objective: To examine temporal trends in DRGs with a major complication or comorbidity, compare these findings with 2 alternative measures of disease severity, and estimate associated changes in payment. Design, Setting, and Participants: This retrospective cohort study used data from the all-payer National Inpatient Sample for admissions assigned to 1 of the top 20 reimbursed DRG families at US acute care hospitals from January 1, 2012, to December 31, 2016. Data were analyzed from July 10, 2018, to May 29, 2019. Exposures: Quarter year of hospitalization. Main Outcomes and Measures: The primary outcome was the proportion of DRGs with a major complication or comorbidity. Secondary outcomes were comorbidity scores, risk-adjusted mortality rates, and estimated payment. Changes in assigned DRGs, comorbidity scores, and risk-adjusted mortality rates were analyzed by linear regression. Payment changes were estimated for each DRG by calculating the Centers for Medicare & Medicaid Services weighted payment using 2012 and 2016 case mix and hospitalization counts. Results: Between 2012 and 2016, there were 62 167 976 hospitalizations for the 20 highest-reimbursed DRG families; the sample was 32.9% male and 66.8% White, with a median age of 57 years (interquartile range, 31-73 years). Within 15 of these DRG families (75%), the proportion of DRGs with a major complication or comorbidity increased significantly over time. Over the same period, comorbidity scores were largely stable, with a decrease in 6 DRG families (30%), no change in 10 (50%), and an increase in 4 (20%). Among 19 DRG families with a calculable mortality rate, the risk-adjusted mortality rate significantly decreased in 8 (42%), did not change in 9 (47%), and increased in 2 (11%). The observed DRG shifts were associated with at least $1.2 billion in increased payment. Conclusions and Relevance: In this cohort study, between 2012 and 2016, the proportion of admissions assigned to a DRG with major complication or comorbidity increased for 15 of the top 20 reimbursed DRG families. This change was not accompanied by commensurate increases in disease severity but was associated with increased payment

Association Between Concussion Burden During Professional American-Style Football and Postcareer Hypertension

Previous work has demonstrated an association between American-style football (ASF) and the development of hypertension among collegiate athletes.1 In addition, hypertension prevalence has been shown to be higher among active professional ASF athletes compared with similarly aged members of the general population.2 Whereas causal factors including deliberate weight gain, repetitive isometric strength training, sleep apnea, and nonsteroidal anti-inflammatory drug use have been suggested, definitive mechanisms remain incompletely understood. Recent studies in general populations have shown associations between brain injury and subsequent hypertension.3 Given that ASF players are at particular risk for recurrent head injury, the relationship between concussion history and later life hypertension deserves focused exploration