The Experts below are selected from a list of 174 Experts worldwide ranked by ideXlab platform
Alik Farber - One of the best experts on this subject based on the ideXlab platform.
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care of patients undergoing vascular surgery at safety net public hospitals is associated with higher cost but similar mortality to Nonsafety net hospitals
Journal of Vascular Surgery, 2014Co-Authors: Mohammad H Eslami, Denis Rybin, Gheorghe Doros, Alik FarberAbstract:Objective This study compared in-hospital mortality and resource utilization among vascular surgical patients at safety net public hospitals (SNPHs) with those at Nonsafety net public hospitals (nSNPHs). Methods The National Inpatient Sample (2003-2011) was queried to identify surgical patients with peripheral arterial disease (PAD), carotid stenosis, or nonruptured abdominal aorta aneurysm based on International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic and procedure codes. The cohort was then divided into SNPH and nSNPH groups according to the definition of SNPH used by the National Association of Public Hospitals. Clinical characteristics, length of stay, in-hospital mortality, and hospital charges were compared between groups. Advanced PAD was defined as that associated with rest pain or tissue loss. Statistical methods included bivariate χ 2 tests for categoric variables, t -tests for continuous variables, and multivariable linear and logistic regression to adjust for confounding variables (in-hospital mortality). Results We identified 306,438 patients operated on for PAD, carotid stenosis, and abdominal aortic aneurysm. Patients at SNPHs were younger, the percentage of female and minority patients was higher, and patients had a higher Elixhauser comorbidity index ( P P > .05) and symptomatic carotid stenosis ( P P P Conclusions Patients undergoing vascular surgery at SNPHs, despite being younger, had higher comorbidities, presented more urgently with more advanced disease, and incurred higher costs than the SNPH cohort despite similar adjusted odds of in-hospital mortality. Delayed presentation and higher comorbidities are most likely related to poor access to routine and preventive health care for the SNPH patients.
David Walker - One of the best experts on this subject based on the ideXlab platform.
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Run-time enforcement of Nonsafety policies
2012Co-Authors: Jay Ligatti, Lujo Bauer, David WalkerAbstract:A common mechanism for ensuring that software behaves securely is to monitor programs at run time and check that they dynamically adhere to constraints specified by a security policy. Whenever a program monitor detects that untrusted software is attempting to execute a dangerous action, it takes remedial steps to ensure that only safe code actually gets executed. This article improves our understanding of the space of policies enforceable by monitoring the run-time behaviors of programs. We begin by building a formal framework for analyzing policy enforcement: we precisely define policies, monitors, and enforcement. This framework allows us to prove that monitors enforce an interesting set of policies that we call the infinite renewal properties. We show how to construct a program monitor that provably enforces any reasonable infinite renewal property. We also show that the set of infinite renewal properties includes some Nonsafety policies, i.e., that monitors can enforce some Nonsafety (including some purely liveness) policies. Finally, we demonstrate concrete examples of Nonsafety policies enforceable by practical run-time monitors. Categories and Subject Descriptors: D.2.0 [Software Engineering]: General—protection mechanisms
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run time enforcement of Nonsafety policies
ACM Transactions on Information and System Security, 2009Co-Authors: Jay Ligatti, Lujo Bauer, David WalkerAbstract:A common mechanism for ensuring that software behaves securely is to monitor programs at run time and check that they dynamically adhere to constraints specified by a security policy. Whenever a program monitor detects that untrusted software is attempting to execute a dangerous action, it takes remedial steps to ensure that only safe code actually gets executed.This article improves our understanding of the space of policies enforceable by monitoring the run-time behaviors of programs. We begin by building a formal framework for analyzing policy enforcement: we precisely define policies, monitors, and enforcement. This framework allows us to prove that monitors enforce an interesting set of policies that we call the infinite renewal properties. We show how to construct a program monitor that provably enforces any reasonable infinite renewal property. We also show that the set of infinite renewal properties includes some Nonsafety policies, that is, that monitors can enforce some Nonsafety (including some purely liveness) policies. Finally, we demonstrate concrete examples of Nonsafety policies enforceable by practical run-time monitors.
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Run-time enforcement of Nonsafety policies
2009Co-Authors: Jay Ligatti, Lujo Bauer, David WalkerAbstract:A common mechanism for ensuring that software behaves securely is to monitor programs at run time and check that they dynamically adhere to constraints specified by a security policy. Whenever a program monitor detects that untrusted software is attempting to execute a dangerous action, it takes remedial steps to ensure that only safe code actually gets executed. This article improves our understanding of the space of policies enforceable by monitoring the run-time behaviors of programs. We begin by building a formal framework for analyzing policy enforcement: we precisely define policies, monitors, and enforcement. This framework allows us to prove that monitors enforce an interesting set of policies that we call the infinite renewal properties. We show how to construct a program monitor that provably enforces any reasonable infinite renewal property. We also show that the set of infinite renewal properties includes some Nonsafety policies, that is, that monitors can enforce some Nonsafety (including some purely liveness) policies. Finally, we demonstrate concrete examples of Nonsafety policies enforceable by practical run-time monitors. Categories and Subject Descriptors: D.2.0 [Software Engineering]: General—protection mechanisms; F.1.2 [Computation by Abstract Devices]: Modes of Computation—interactive an
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Run-time Enforcement of Nonsafety Policies
2008Co-Authors: Jay Ligatti, Lujo Bauer, David WalkerAbstract:A common mechanism for ensuring that software behaves securely is to monitor programs at run time and check that they dynamically adhere to constraints specified by a security policy. Whenever a program monitor detects that untrusted software is attempting to execute a dangerous action, it takes remedial steps to ensure that only safe code actually gets executed. This article improves our understanding of the space of policies enforceable by monitoring the run-time behaviors of programs. We begin by building a formal framework for analyzing policy enforcement: we precisely define policies, monitors, and enforcement. This framework allows us to prove that monitors enforce an interesting set of policies that we call the infinite renewal properties. We show how, when given any reasonable infinite renewal property, to construct a program monitor that provably enforces that policy. We also show that the set of infinite renewal properties includes some Nonsafety policies, i.e., that monitors can enforce some Nonsafety (including some purely liveness) policies. Finally, we demonstrate concrete examples of Nonsafety policies enforceable by practical run-time monitors. Categories and Subject Descriptors: D.2.0 [Software Engineering]: General—protection mechanisms
Mohammad H Eslami - One of the best experts on this subject based on the ideXlab platform.
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care of patients undergoing vascular surgery at safety net public hospitals is associated with higher cost but similar mortality to Nonsafety net hospitals
Journal of Vascular Surgery, 2014Co-Authors: Mohammad H Eslami, Denis Rybin, Gheorghe Doros, Alik FarberAbstract:Objective This study compared in-hospital mortality and resource utilization among vascular surgical patients at safety net public hospitals (SNPHs) with those at Nonsafety net public hospitals (nSNPHs). Methods The National Inpatient Sample (2003-2011) was queried to identify surgical patients with peripheral arterial disease (PAD), carotid stenosis, or nonruptured abdominal aorta aneurysm based on International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic and procedure codes. The cohort was then divided into SNPH and nSNPH groups according to the definition of SNPH used by the National Association of Public Hospitals. Clinical characteristics, length of stay, in-hospital mortality, and hospital charges were compared between groups. Advanced PAD was defined as that associated with rest pain or tissue loss. Statistical methods included bivariate χ 2 tests for categoric variables, t -tests for continuous variables, and multivariable linear and logistic regression to adjust for confounding variables (in-hospital mortality). Results We identified 306,438 patients operated on for PAD, carotid stenosis, and abdominal aortic aneurysm. Patients at SNPHs were younger, the percentage of female and minority patients was higher, and patients had a higher Elixhauser comorbidity index ( P P > .05) and symptomatic carotid stenosis ( P P P Conclusions Patients undergoing vascular surgery at SNPHs, despite being younger, had higher comorbidities, presented more urgently with more advanced disease, and incurred higher costs than the SNPH cohort despite similar adjusted odds of in-hospital mortality. Delayed presentation and higher comorbidities are most likely related to poor access to routine and preventive health care for the SNPH patients.
Gloria J. Bazzoli - One of the best experts on this subject based on the ideXlab platform.
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Medicare Payment Penalties and Safety Net Hospital Profitability: Minimal Impact on These Vulnerable Hospitals.
Health services research, 2018Co-Authors: Gloria J. Bazzoli, Michael P. Thompson, Teresa M. WatersAbstract:OBJECTIVE To examine relationships between penalties assessed by Medicare's Hospital Readmission Reduction Program and Value-Based Purchasing Program and hospital financial condition. DATA SOURCES/STUDY SETTING Centers for Medicare and Medicaid Services, American Hospital Association, and Area Health Resource File data for 4,824 hospital-year observations. STUDY DESIGN Bivariate and multivariate analysis of pooled cross-sectional data. PRINCIPAL FINDINGS Safety net hospitals have significantly higher HRRP/VBP penalties, but, unlike Nonsafety net hospitals, increases in their penalty rate did not significantly affect their total margins. CONCLUSIONS Safety net hospitals appear to rely on nonpatient care revenues to offset higher penalties for the years studied. While reassuring, these funding streams are volatile and may not be able to compensate for cumulative losses over time.
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the effect of changes in hospital reimbursement on nurse staffing decisions at safety net and Nonsafety net hospitals
Health Services Research, 2006Co-Authors: Richard C Lindrooth, Gloria J. Bazzoli, Jack Needleman, Romana HasnainwyniaAbstract:The Balanced Budget Act of 1997 (BBA) led to the largest change in hospital Medicare payments since the implementation of the Prospective Payment System of 1983. The Congressional Budget Office (CBO) originally forecasted a reduction of $115 billion in Medicare expenditures owing to the BBA (Ernst & Young and HCIA-Sachs 2000). However, soon after the implementation, the CBO increased its original forecast of cost reductions to $227 billion between 1998 and 2002. The cost reductions in the first year were substantial; clearly there was an immediate effect on hospital finances. However, various provisions of the BBA were relaxed and delayed in subsequent years, leading to a gradual increase in expenditures. We measure how the potential changes in BBA-related reimbursement affect hospital nurse staffing decisions at urban short-term general hospitals. We identify the incremental effect of the BBA on nurse staffing by comparing hospitals that were most likely to be affected by the BBA with hospitals that were least likely to be affected. We focus on nurse staffing because, while the reduction in Medicare expenditure was substantial, such reductions may have deleterious effects on quality. A primary mechanism by which quality would be affected is nurse staffing levels. Our study is in the spirit of the Buerhaus and Staiger studies in that we seek to establish a link between payers and staffing levels. Buerhaus and Staiger (1996, 1999) found that the growth of managed care led to a decline in nurse staffing and wages. Further, Aiken et al. (2002) found that higher caseloads were a significant determinant of burnout and decreased job satisfaction, which can lead to nurses leaving the hospital workforce. Spetz (1999) found managed care was associated with fewer LPNs and aides. Provisions, such as the BBA, may affect staffing levels if lowered reimbursement makes hospitals unable to continue staffing at levels commensurate with the number of patients days or admissions.1 Several recent studies have shown that nurse staffing has important implications for the quality of hospital care. Needleman et al. (2002) found that the proportion of registered nurses (RNs) providing nursing care and the number of hours provided by RNs was positively associated with quality of care. They also found that the level of staffing by RNs was not associated with the rate of in-hospital mortality. Kovner et al. (2002) found that a reduction in nurse hours per adjusted patient day was associated with an increase in pneumonia for routine and emergency admissions. Aiken et al. (2002) reported that each additional patient per nurse led to a 7 percent increase in the probability of dying within 30 days of admission and a 7 percent increase in the probability of failure-to-rescue. These results are generally consistent with other studies that found that patient quality and outcomes of care are positively associated with increases in nurse-to-patient staffing levels, increased RN proportions in total nursing staff, and reduced nursing workloads (Manheim et al. 1992; Taunton et al. 1994; Silber and Rosenbaum 1995; Blegen and Vaughan 1998; Blegen, Goode, and Reed 1998; Kovner and Gergen 1998; McCloskey 1998; Schultz et al. 1998, 1999; Lichtig, Knauf, and Miholland 1999; Pronovost et al. 1999; van Servellen and Schultz 1999; Mark et al. 2004). In this article, we look at RN and licensed practical nurse (LPN) staffing ratios separately. We do so because most of the literature cited above either focuses on the number of RNs or the ratio of RNs to LPNs as an indicator of quality. RNs are, by far, the most common type of nurses in inpatient care settings. We include LPNs because LPN positions are often the first to get cut when financial conditions worsen because they require less training and acquire fewer firm-specific skills. In this analysis, we also test whether safety net hospitals react differently to the BBA than Nonsafety net hospitals. Hoerger (1991), using data from the mid- to late-1980s, found that nonprofit hospitals and, to a lesser extent, publicly owned hospitals have less volatile net income (or loss)2 than for-profit hospitals. Hoerger tied this result to utility (as opposed to profit) maximization and suggested that a “hospital may reduce its quality or cut back on its provision of free care”3 if there is an exogenous reduction in payments in order to satisfy its profit constraint. Clearly, nurse staffing is one mechanism by which hospitals might cut back on quality. The other is uncompensated care. However, a Nonsafety net hospital, by definition, does not provide a large amount of uncompensated care either in terms of market share or as a proportion of its total revenue. Thus, lowering uncompensated care in response to changes in reimbursement is unlikely to have a significant effect on a Nonsafety net hospital's income statement. Thus, staffing ratios are one of the main tools administrators at Nonsafety net hospitals have to cut costs. In contrast, the effect of the BBA on staffing ratios may be lower at safety net hospitals because uncompensated care may also adjust in response to changes in reimbursement. In the next section, we describe the BBA and its subsequent revisions, and we describe how the brunt of the reductions occurred during the first year and were relaxed subsequently. This is followed by an explanation of our methods and results.
Romana Hasnainwynia - One of the best experts on this subject based on the ideXlab platform.
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the effect of changes in hospital reimbursement on nurse staffing decisions at safety net and Nonsafety net hospitals
Health Services Research, 2006Co-Authors: Richard C Lindrooth, Gloria J. Bazzoli, Jack Needleman, Romana HasnainwyniaAbstract:The Balanced Budget Act of 1997 (BBA) led to the largest change in hospital Medicare payments since the implementation of the Prospective Payment System of 1983. The Congressional Budget Office (CBO) originally forecasted a reduction of $115 billion in Medicare expenditures owing to the BBA (Ernst & Young and HCIA-Sachs 2000). However, soon after the implementation, the CBO increased its original forecast of cost reductions to $227 billion between 1998 and 2002. The cost reductions in the first year were substantial; clearly there was an immediate effect on hospital finances. However, various provisions of the BBA were relaxed and delayed in subsequent years, leading to a gradual increase in expenditures. We measure how the potential changes in BBA-related reimbursement affect hospital nurse staffing decisions at urban short-term general hospitals. We identify the incremental effect of the BBA on nurse staffing by comparing hospitals that were most likely to be affected by the BBA with hospitals that were least likely to be affected. We focus on nurse staffing because, while the reduction in Medicare expenditure was substantial, such reductions may have deleterious effects on quality. A primary mechanism by which quality would be affected is nurse staffing levels. Our study is in the spirit of the Buerhaus and Staiger studies in that we seek to establish a link between payers and staffing levels. Buerhaus and Staiger (1996, 1999) found that the growth of managed care led to a decline in nurse staffing and wages. Further, Aiken et al. (2002) found that higher caseloads were a significant determinant of burnout and decreased job satisfaction, which can lead to nurses leaving the hospital workforce. Spetz (1999) found managed care was associated with fewer LPNs and aides. Provisions, such as the BBA, may affect staffing levels if lowered reimbursement makes hospitals unable to continue staffing at levels commensurate with the number of patients days or admissions.1 Several recent studies have shown that nurse staffing has important implications for the quality of hospital care. Needleman et al. (2002) found that the proportion of registered nurses (RNs) providing nursing care and the number of hours provided by RNs was positively associated with quality of care. They also found that the level of staffing by RNs was not associated with the rate of in-hospital mortality. Kovner et al. (2002) found that a reduction in nurse hours per adjusted patient day was associated with an increase in pneumonia for routine and emergency admissions. Aiken et al. (2002) reported that each additional patient per nurse led to a 7 percent increase in the probability of dying within 30 days of admission and a 7 percent increase in the probability of failure-to-rescue. These results are generally consistent with other studies that found that patient quality and outcomes of care are positively associated with increases in nurse-to-patient staffing levels, increased RN proportions in total nursing staff, and reduced nursing workloads (Manheim et al. 1992; Taunton et al. 1994; Silber and Rosenbaum 1995; Blegen and Vaughan 1998; Blegen, Goode, and Reed 1998; Kovner and Gergen 1998; McCloskey 1998; Schultz et al. 1998, 1999; Lichtig, Knauf, and Miholland 1999; Pronovost et al. 1999; van Servellen and Schultz 1999; Mark et al. 2004). In this article, we look at RN and licensed practical nurse (LPN) staffing ratios separately. We do so because most of the literature cited above either focuses on the number of RNs or the ratio of RNs to LPNs as an indicator of quality. RNs are, by far, the most common type of nurses in inpatient care settings. We include LPNs because LPN positions are often the first to get cut when financial conditions worsen because they require less training and acquire fewer firm-specific skills. In this analysis, we also test whether safety net hospitals react differently to the BBA than Nonsafety net hospitals. Hoerger (1991), using data from the mid- to late-1980s, found that nonprofit hospitals and, to a lesser extent, publicly owned hospitals have less volatile net income (or loss)2 than for-profit hospitals. Hoerger tied this result to utility (as opposed to profit) maximization and suggested that a “hospital may reduce its quality or cut back on its provision of free care”3 if there is an exogenous reduction in payments in order to satisfy its profit constraint. Clearly, nurse staffing is one mechanism by which hospitals might cut back on quality. The other is uncompensated care. However, a Nonsafety net hospital, by definition, does not provide a large amount of uncompensated care either in terms of market share or as a proportion of its total revenue. Thus, lowering uncompensated care in response to changes in reimbursement is unlikely to have a significant effect on a Nonsafety net hospital's income statement. Thus, staffing ratios are one of the main tools administrators at Nonsafety net hospitals have to cut costs. In contrast, the effect of the BBA on staffing ratios may be lower at safety net hospitals because uncompensated care may also adjust in response to changes in reimbursement. In the next section, we describe the BBA and its subsequent revisions, and we describe how the brunt of the reductions occurred during the first year and were relaxed subsequently. This is followed by an explanation of our methods and results.
