279 research outputs found
Hospital Admissions, Length of Stay, and Case-Mix Impacts of Per Case Payment: The Maryland Experience
Maryland has simultaneously operated per case - and per service hospital payment systems since 1976 with varying levels of stringency in setting per case rates. Regression analyses of this experience are used to compare the impacts of these systems on admissions, length of stay, and case-mix costliness for the period July 1, 1976 to June 30, 1981. Our results indicate a positive effect on admissions and negative effects on case-mix and length of stay for the per case payment approach relative to the per service approach. More stringent levels of per case payment are associated with stronger utilization responses.
Hospital Cost and Efficiency Under Per Service and Per Case Payment in Maryland: A Tale of the Carrot and the Stick
The simultaneous operation of per case and per servicepayment systems in Maryland, and the varying levels of stringency used in setting per case rates allows comparison of effects of differing incentive structures on hospital costs. This paper presents such a comparison with 1977-1981 data. Cost per case and total cost regressions show evidence of lower costs only when per case payment limits are very stringent. Positive net revenue incentives appear insufficient to induce reductions in length of stay and in ancillary services use. Our results suggest these changes in medical practice patterns are more likely under the threat of financial losses.
Renormalization of Horava Gravity
We prove perturbative renormalizability of projectable Horava gravity. The
key element of the argument is the choice of a gauge which ensures the correct
anisotropic scaling of the propagators and their uniform falloff at large
frequencies and momenta. This guarantees that the counterterms required to
absorb the loop divergences are local and marginal or relevant with respect to
the anisotropic scaling. Gauge invariance of the counterterms is achieved by
making use of the background-covariant formalism. We also comment on the
difficulties of this approach when addressing the renormalizability of the
non-projectable model.Comment: 35 pages, no figures; references discussing gauge invariance of
counterterms have been added, typos correcte
Renormalization of gauge theories in the background-field approach
Using the background-field method we demonstrate the
Becchi-Rouet-Stora-Tyutin (BRST) structure of counterterms in a broad class of
gauge theories. Put simply, we show that gauge invariance is preserved by
renormalization in local gauge field theories whenever they admit a sensible
background-field formulation and anomaly-free path integral measure. This class
encompasses Yang-Mills theories (with possibly Abelian subgroups) and
relativistic gravity, including both renormalizable and non-renormalizable
(effective) theories. Our results also hold for non-relativistic models such as
Yang-Mills theories with anisotropic scaling or Horava gravity. They strengthen
and generalize the existing results in the literature concerning the
renormalization of gauge systems. Locality of the BRST construction is
emphasized throughout the derivation. We illustrate our general approach with
several explicit examples.Comment: 45 pages, no figures; references added, changes in the Introduction
and Conclusion
Ho\v{r}ava gravity is asymptotically free (in 2+1 dimensions)
We compute the -functions of marginal couplings in projectable
Ho\v{r}ava gravity in spacetime dimensions. We show that the
renormalization group flow has an asymptotically-free fixed point in the
ultraviolet (UV), establishing the theory as a UV-complete model with dynamical
gravitational degrees of freedom. Therefore, this theory may serve as a
toy-model to study fundamental aspects of quantum gravity. Our results
represent a step forward towards understanding the UV properties of realistic
versions of Ho\v{r}ava gravity.Comment: Updated references, minor revisions. Matches journal versio
Orbital operations study. Appendix B: Operational procedures
Operational procedures for each alternate approach for each interfacing activity of the orbital operations study are presented. The applicability of the procedures to interfacing element pairs is identified
Disparities in use of mental health and substance abuse services by Asian and Native Hawaiian/Other Pacific Islander women
The purpose of this study was to determine if disparities exist in lifetime utilization of mental health/substance abuse services among Asian, Native Hawaiian/Other Pacific Islander (NHOPI) and white mothers. The study sample was comprised of mothers assessed to be at-risk (n = 491) and not at-risk (n = 218) for child maltreatment in the Hawaii Healthy Start Program study. Multiple logistic regression models were used to test the effects of predisposing, need, and enabling factors on utilization of services. Results revealed that, among mothers with depressive symptoms, compared with whites, Asians and NHOPI were significantly less likely to have received services. There were no significant racial differences in use of mental health/substance use services by other factors. These results suggest that racial disparities exist in utilization of mental health/substance abuse services among mothers with depressive symptoms. Future research is needed to identify barriers and facilitators to accessing needed services for Asian and NHOPI women
Renormalization Group Flow in Scalar-Tensor Theories. II
We study the UV behaviour of actions including integer powers of scalar
curvature and even powers of scalar fields with Functional Renormalization
Group techniques. We find UV fixed points where the gravitational couplings
have non-trivial values while the matter ones are Gaussian. We prove several
properties of the linearized flow at such a fixed point in arbitrary dimensions
in the one-loop approximation and find recursive relations among the critical
exponents. We illustrate these results in explicit calculations in for
actions including up to four powers of scalar curvature and two powers of the
scalar field. In this setting we notice that the same recursive properties
among the critical exponents, which were proven at one-loop order, still hold,
in such a way that the UV critical surface is found to be five dimensional. We
then search for the same type of fixed point in a scalar theory with minimal
coupling to gravity in including up to eight powers of scalar curvature.
Assuming that the recursive properties of the critical exponents still hold,
one would conclude that the UV critical surface of these theories is five
dimensional.Comment: 14 pages. v.2: Minor changes, some references adde
Gel-type autologous chondrocyte (Chondron™) implantation for treatment of articular cartilage defects of the knee
<p>Abstract</p> <p>Background</p> <p>Gel-type autologous chondrocyte (Chondron™) implantations have been used for several years without using periosteum or membrane. This study involves evaluations of the clinical results of Chondron™ at many clinical centers at various time points during the postoperative patient follow-up.</p> <p>Methods</p> <p>Data from 98 patients with articular cartilage injury of the knee joint and who underwent Chondron™ implantation at ten Korean hospitals between January 2005 and November 2008, were included and were divided into two groups based on the patient follow-up period, i.e. 13~24-month follow-up and greater than 25-month follow-up. The telephone Knee Society Score obtained during telephone interviews with patients, was used as the evaluation tool.</p> <p>Results</p> <p>On the tKSS-A (telephone Knee Society Score-A), the score improved from 43.52 ± 20.20 to 89.71 ± 13.69 (P < 0.05), and on the tKSS-B (telephone Knee Society Score-B), the score improved from 50.66 ± 20.05 to 89.38 ± 15.76 (P < 0.05). The total improvement was from 94.18 ± 31.43 to 179.10 ± 24.69 (P < 0.05).</p> <p>Conclusion</p> <p>Gel-type autologous chondrocyte implantation for chondral knee defects appears to be a safe and effective method for both decreasing pain and improving knee function.</p
Supergravity based inflation models: a review
In this review, we discuss inflation models based on supergravity. After
explaining the difficulties in realizing inflation in the context of
supergravity, we show how to evade such difficulties. Depending on types of
inflation, we give concrete examples, particularly paying attention to chaotic
inflation because the ongoing experiments like Planck might detect the tensor
perturbations in near future. We also discuss inflation models in Jordan frame
supergravity, motivated by Higgs inflation.Comment: 30 pages, invited review for Classical and Quantum Gravity, published
versio
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