Hospital implementation of health information technology and quality of care: are they related?

Recently, there has been considerable effort to promote the use of health information technology (HIT) in order to improve health care quality. However, relatively little is known about the extent to which HIT implementation is associated with hospital patient care quality. We undertook this study to determine the association of various HITs with: hospital quality improvement (QI) practices and strategies; adherence to process of care measures; risk-adjusted inpatient mortality; patient satisfaction; and assessment of patient care quality by hospital quality managers and front-line clinicians.This work was supported by a grant from the Commonwealth Fund. We are indebted to Anthony Shih and Anne-Marie Audet of the Fund for their advice, support, and constructive suggestions throughout the design and conduct of the study. We thank our colleagues - Raymond Kang, Peter Kralovec, Sally Holmes, Frances Margolin, and Deborah Bohr - for their valuable contributions to the development of the QAS, the CPS, and the database on which the analytic findings reported here were based. We also thank 3 M (TM) Health Information Systems' for use of its All Patient Refined Diagnosis Related Groups (APR-DRGs) software. We especially wish to thank Jennifer Drake for her contributions not only to survey development, but also to earlier analysis of survey findings relevant to this paper. (Commonwealth Fund)Published versio

New results in rho^0 meson physics

We compare the predictions of a range of existing models based on the Vector Meson Dominance hypothesis with data on e^+ e^- -> pi^+ pi^$ and e^+ e^- -> mu^+ mu^- cross-sections and the phase and near-threshold behavior of the timelike pion form factor, with the aim of determining which (if any) of these models is capable of providing an accurate representation of the full range of experimental data. We find that, of the models considered, only that proposed by Bando et al. is able to consistently account for all information, provided one allows its parameter "a" to vary from the usual value of 2 to 2.4. Our fit with this model gives a point-like coupling (gamma pi^+ \pi^-) of magnitude ~ -e/6, while the common formulation of VMD excludes such a term. The resulting values for the rho mass and pi^+ pi^- and e^+e^- partial widths as well as the branching ratio for the decay omega -> pi^+ pi^- obtained within the context of this model are consistent with previous results.Comment: 34 pages with 7 figures. Published version also available at http://link.springer.de/link/service/journals/10052/tocs/t8002002.ht

Generalized Shortest Path Kernel on Graphs

We consider the problem of classifying graphs using graph kernels. We define a new graph kernel, called the generalized shortest path kernel, based on the number and length of shortest paths between nodes. For our example classification problem, we consider the task of classifying random graphs from two well-known families, by the number of clusters they contain. We verify empirically that the generalized shortest path kernel outperforms the original shortest path kernel on a number of datasets. We give a theoretical analysis for explaining our experimental results. In particular, we estimate distributions of the expected feature vectors for the shortest path kernel and the generalized shortest path kernel, and we show some evidence explaining why our graph kernel outperforms the shortest path kernel for our graph classification problem.Comment: Short version presented at Discovery Science 2015 in Banf

Non-meanfield deterministic limits in chemical reaction kinetics far from equilibrium

A general mechanism is proposed by which small intrinsic fluctuations in a system far from equilibrium can result in nearly deterministic dynamical behaviors which are markedly distinct from those realized in the meanfield limit. The mechanism is demonstrated for the kinetic Monte-Carlo version of the Schnakenberg reaction where we identified a scaling limit in which the global deterministic bifurcation picture is fundamentally altered by fluctuations. Numerical simulations of the model are found to be in quantitative agreement with theoretical predictions.Comment: 4 pages, 4 figures (submitted to Phys. Rev. Lett.

The Computational Power of Optimization in Online Learning

We consider the fundamental problem of prediction with expert advice where the experts are "optimizable": there is a black-box optimization oracle that can be used to compute, in constant time, the leading expert in retrospect at any point in time. In this setting, we give a novel online algorithm that attains vanishing regret with respect to $N$ experts in total $\widetilde{O}(\sqrt{N})$ computation time. We also give a lower bound showing that this running time cannot be improved (up to log factors) in the oracle model, thereby exhibiting a quadratic speedup as compared to the standard, oracle-free setting where the required time for vanishing regret is $\widetilde{\Theta}(N)$. These results demonstrate an exponential gap between the power of optimization in online learning and its power in statistical learning: in the latter, an optimization oracle---i.e., an efficient empirical risk minimizer---allows to learn a finite hypothesis class of size $N$ in time $O(\log{N})$. We also study the implications of our results to learning in repeated zero-sum games, in a setting where the players have access to oracles that compute, in constant time, their best-response to any mixed strategy of their opponent. We show that the runtime required for approximating the minimax value of the game in this setting is $\widetilde{\Theta}(\sqrt{N})$, yielding again a quadratic improvement upon the oracle-free setting, where $\widetilde{\Theta}(N)$ is known to be tight

A Novel Measure to Assess Variation in Hepatitis C Prevalence Among Homeless and Unstably Housed Veterans, 2011-2016.

We constructed a novel measure of homelessness to examine differences in hepatitis C virus (HCV) prevalence across 3 categories of unstably housed and homeless veterans and across US Department of Veterans Affairs Medical Center facilities. We used Veterans Affairs administrative data to classify a cohort of 434 240 veterans as at risk of homelessness, currently homeless, or formerly homeless, and we examined variation in HCV prevalence by using descriptive measures and mixed-effect logistic regression models. HCV prevalence was highest among veterans who were formerly homeless (16.7%; 32 490 of 195 000), followed by currently homeless (12.4%; 22 050 of 178 056) and at risk of homelessness (8.2%; 5015 of 61 184). Veterans Affairs Medical Center-level prevalence ranged from 5.4% to 21.5%. Differences in HCV prevalence were significant by sex, race/ethnicity, and age. Targeting specific populations of homeless veterans for tailored HCV interventions and allocating additional resources to certain Veterans Affairs Medical Centers may be warranted

Is the Availability of Direct-Acting Antivirals Associated with Increased Access to Hepatitis C Treatment for Homeless and Unstably Housed Veterans?

OBJECTIVE: Hepatitis C virus (HCV) treatment has experienced a rapid transformation in the USA. New direct-acting antiviral (DAA) medications make treatment easier, less toxic, and more successful (90% or greater viral cure) than prior, interferon-based HCV medications. We sought to determine whether DAAs may have improved access to HCV treatment for hard-to-reach populations such as the homeless. METHODS: In a retrospective study of VA electronic medical record data, a cohort was created of 63,586 veterans with a positive HCV RNA or genotype test taken at any point from January 1, 2012, through December 31, 2016. Patient data were examined for up to 5 years using a discrete time survival model to assess the relationship between their housing status and receipt of HCV medications in 6-month time periods in both the interferon and DAA eras. RESULTS: In the interferon era, the probability of HCV treatment in a given 6-month window among housed veterans, at 6.2% (95% CI: 5.3-7.1%) was significantly higher than among veterans who were homeless or unstably housed; for example, among currently homeless veterans, the probability of treatment initiation, in a given 6-month window, was 2.6% (95% CI: 1.9-3.3%). With the arrival of DAAs, each housing category had an increased probability of treatment initiation. For housed veterans, the probability was 8.6% (95% CI: 8.3-8.9%) while for currently homeless veterans, it was 6.3% (95% CI: 5.7-6.9%). CONCLUSIONS: We found a clear indication that the likelihood of treatment initiation was greater for all veterans in the DAA era as compared to the interferon era. However, disparities in treatment initiation rates between housed and homeless veterans that were observed in the interferon era persisted in the DAA era

Largeness and SQ-universality of cyclically presented groups

Largeness, SQ-universality, and the existence of free subgroups of rank 2 are measures of the complexity of a finitely presented group. We obtain conditions under which a cyclically presented group possesses one or more of these properties. We apply our results to a class of groups introduced by Prishchepov which contains, amongst others, the various generalizations of Fibonacci groups introduced by Campbell and Robertson