1,291 research outputs found
Comparing methods of grouping hospitals
ObjectiveTo compare the performance of widely used approaches for defining groups of hospitals and a new approach based on network analysis of shared patient volume.Study SettingNonâ federal acute care hospitals in the United States.Study DesignWe assessed the measurement properties of four methods of grouping hospitals: hospital referral regions (HRRs), metropolitan statistical areas (MSAs), coreâ based statistical areas (CBSAs), and community detection algorithms (CDAs).Data Extraction MethodsWe combined data from the 2014 American Hospital Association Annual Survey, the Census Bureau, the Dartmouth Atlas, and Medicare data on interhospital patient travel patterns. We then evaluated the distinctiveness of each grouping, reliability over time, and generalizability across populations.Principle FindingsHospital groups defined by CDAs were the most distinctive (modularity = 0.86 compared to 0.75 for HRRs and 0.83 for MSAs; 0.72 for CBSA), were reliable to alternative specifications, and had greater generalizability than HRRs, MSAs, or CBSAs. CDAs had lower reliability over time than MSAs or CBSAs (normalized mutual information between 2012 and 2014 CDAs = 0.93).ConclusionsCommunity detection algorithmâ defined hospital groups offer high validity, reliability to different specifications, and generalizability to many uses when compared to approaches in widespread use today. They may, therefore, offer a better choice for efforts seeking to analyze the behaviors and dynamics of groups of hospitals. Measures of modularity, shared information, inclusivity, and shared behavior can be used to evaluate different approaches to grouping providers.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151847/1/hesr13188-sup-0001-AuthorMatrix.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151847/2/hesr13188_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151847/3/hesr13188.pd
Five-year survival after surgical treatment for kidney cancer
BACKGROUND. Kidney cancer's rising incidence is largely attributable to the increased detection of small renal masses. Although surgery rates have paralleled this incidence trend, mortality continues to rise, calling into question the necessity of surgery for all patients with renal masses. Using a population-based cohort, a competing risk analysis was performed to estimate patient survival after surgery for kidney cancer, as a function of patient age and tumor size at diagnosis. METHODS. With data from the Surveillance, Epidemiology, and End Results Program (1983–2002), a cohort was assembled of 26,618 patients with surgically treated, local-regional kidney cancer. Patients were sorted into 20 age-tumor size categories and the numbers of patients that were alive, dead from kidney cancer, and dead from other causes were tabulated. Poisson regression models were fitted to obtain estimates of cancer-specific and competing-cause mortality. RESULTS. Age-specific kidney cancer mortality was stable across all size strata but varied inversely with tumor size. Patients with the smallest tumors enjoyed the lowest cancer-specific mortality (5% for masses ≤4 cm). Competing-cause mortality rose with increasing patient age. The estimated 5-year competing-cause mortality for elderly subjects (≥70 years) was 28.2% (95% confidence interval [CI]: 25.9%–30.8%), irrespective of tumor size. CONCLUSIONS. Despite surgical therapy, competing-cause mortality for patients with renal masses rises with increasing patient age. After 5 years, one-third of elderly patients (≥70 years) will die from other causes, suggesting the need for prospective studies to evaluate the role of active surveillance as an initial therapeutic approach for some small renal masses. Cancer 2007. © 2007 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55991/1/22600_ftp.pd
Phospholipase A 2 Modulates Different Subtypes of Excitatory Amino Acid Receptors: Autoradiographic Evidence
Exogenous phospholipases have been used extensively as tools to study the role of membrane lipids in receptor mechanisms. We used in vitro quantitative autoradiography to evaluate the effect of phospholipase A 2 (PLA 2 ) on N -methyl-D-aspartate (NMDA) and non-NMDA glutamate receptors in rat brain. PLA 2 pretreatment induced a significant increase in Α-[ 3 H]amino-3-hydroxy-5-methylisoxazole-4-propionate ([ 3 H]AMPA) binding in the stratum radiatum of the CA1 region of the hippocampus and in the stratum moleculare of the cerebellum. No modification of [ 3 H]AMPA binding was found in the stratum pyramidale of the hippocampus at different ligand concentrations. [ 3 H]-Glutamate binding to the metabotropic glutamate receptor and the non-NMDA-, non-kainate-, non-quisqualate-sensitive [ 3 H]glutamate binding site were also increased by PLA 2 pretreatment. [ 3 H]Kainate binding and NMDA-sensitive [ 3 H]glutamate binding were minimally affected by the enzyme pretreatment. The PLA 2 effect was reversed by EGTA, the PLA 2 inhibitor p -bromophenacyl bromide, and prolonged pretreatment with heat. Bovine serum albumin (1%) prevented the increase in metabotropic binding by PLA 2 . Arachidonic acid failed to mimic the PLA 2 effect on metabotropic binding. These results indicate that PLA 2 can selectively modulate certain subtypes of excitatory amino acid receptors. This effect is due to the enzymatic activity but is probably not correlated with the formation of arachidonic acid metabolites. Independent of their possible physiological implications, our results provide the first autoradiographic evidence that an enzymatic treatment can selectively affect the binding properties of excitatory amino acid receptors in different regions of the CNS.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66358/1/j.1471-4159.1993.tb05843.x.pd
Effects of the Medicare Modernization Act on Spending for Outpatient Surgery
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/1/hesr12807_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/2/hesr12807-sup-0001-AppendixSA1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145408/3/hesr12807.pd
Species distribution modeling predicts significant declines in coralline algae populations under projected climate change with implications for conservation policy
Funding: This work was funded by a NERC iCASE studentship award to HB, PH, JB, and TF (NE/R007233/1). The Royal Botanic Garden Edinburgh acknowledges funding support from the Scottish Government Rural and Environment Sciences and Analytical Services Division (RESAS). This is a contribution to the Scottish Blue Carbon Forum.Anthropogenic climate change presents a major challenge to coastal ecosystems. Mass population declines or geographic shifts in species ranges are expected to occur, potentially leading to wide-scale ecosystem disruption or collapse. This is particularly important for habitat-forming species such as free-living non-geniculate coralline algae that aggregate to form large, structurally complex reef-life ecosystems with high associated biodiversity and carbon sequestration capability. Coralline algal beds have a worldwide distribution, but have recently experienced global declines due to anthropogenic pressures and changing environmental conditions. However, the environmental factors controlling coralline algal bed distribution remain poorly understood, limiting our ability to make adequate assessments of how populations may change in the future. We constructed the first species distribution model for non-geniculate coralline algae (focusing on maerl-forming species but including crustose coralline algae associated with coralline algal beds) and showed that bathymetry, temperature at the seabed and light availability are the primary environmental drivers of present-day non-geniculate coralline algae distribution. Our model also identifies suitable areas for species presence that currently lack records of occurrence. Large-scale spatial declines in coralline algal distribution were observed under all IPCC Representative Concentration Pathways (ranging from 38% decline under RCP 2.6 up to 84% decline under RCP 8.5), with the most rapid rate of decline up to 2050. Refuge populations that may persist under projected climate change were also identified – informing priority areas for future conservation efforts to maximize the long-term survival of this globally important ecosystem.Publisher PDFPeer reviewe
Ureteral Stents for Impassable Ureteroscopy
Background: For the narrow ureter that will not accommodate a ureteroscope, it is common practice to place a ureteral stent, to allow subsequent ureteroscopy in the passively dilated ureter. Surprisingly, there are limited data on the effectiveness or safety of these maneuvers. Methods: We retrospectively analyzed patients managed with ureteral stent placement followed by another attempt at ureteroscopy after an initial attempt of flexible ureteroscopy failed because the ureteroscope would not pass up an otherwise normal ureter. Results: Of 41 patients with follow-up who underwent ureteral stenting for this reason, the ureteroscope passed with ease poststenting in 29 (71%) and there was continued resistance in 12. Of these 12 patients, the ureteroscopy was continued despite resistance in 9, while another stent was placed in the remaining 3. Of these three patients, the third attempt at ureteroscopy was successful in two, and further attempts at ureteroscopy were not made after the third attempt failed in one. With a mean overall follow-up of 32 months, two patients (5%) developed ureteral strictures. Both were among nine patients in whom repeat ureteroscopy was performed despite resistance, with a rate of obstruction of 22% in this subgroup. Overall, ureteral stenting allowed successful ureteroscopy in 98% of patients. Conclusions: Ureteral stenting with subsequent ureteroscopy is a successful and safe method of addressing a narrow ureter that initially does not allow passage of a flexible ureteroscope, as long as persistent subsequent attempts to insert the ureteroscope are made only if it passes easily.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140373/1/end.2012.0414.pd
Ambulatory Surgery Centers and Their Intended Effects on Outpatient Surgery
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113726/1/hesr12278.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113726/2/hesr12278-sup-0001-AppendixSA1.pd
Trends in the Treatment of Adults with Ureteropelvic Junction Obstruction
Background and Purpose: Minimally invasive pyeloplasty is an effective treatment for patients with ureteropelvic junction obstruction that offers quicker convalescence than open pyeloplasty. Technical challenges, however, may have limited its dissemination. We examined population trends and determinants of surgical options for ureteropelvic junction obstruction. Patients and Methods: Using the State Inpatient and Ambulatory Surgery Databases for Florida, we identified adults who underwent ureteropelvic junction obstruction repair between 2001 and 2009. After determining the surgical approach (minimally invasive pyeloplasty, open pyeloplasty, or endopyelotomy), we estimated annual utilization rates and the effects of patient, surgeon, and hospital predictors on surgery type, using multilevel multinomial logistic regression. Results: Rates of minimally invasive pyeloplasty increased 360% (P for monotonic trendPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140371/1/end.2012.0017.pd
Exit rates of accountable care organizations that serve high proportions of beneficiaries of racial and ethnic minority groups
Importance: The Medicare Shared Savings Program provides financial incentives for accountable care organizations (ACOs) to reduce costs of care. The structure of the shared savings program may not adequately adjust for challenges associated with caring for patients with high medical complexity and social needs, a population disproportionately made up of racial and ethnic minority groups. If so, ACOs serving racial and ethnic minority groups may be more likely to exit the program, raising concerns about the equitable distribution of potential benefits from health care delivery reform efforts.
Objective: To evaluate whether ACOs with a high proportion of beneficaries of racial and ethnic minority groups are more likely to exit the Medicare Shared Savings Program and identify characteristics associated with this disparity.
Design, Setting, and Participants: This retrospective observational cohort study used secondary data on Medicare Shared Savings Program ACOs from January 2012 through December 2018. Bivariate and multivariate cross-sectional regression analyses were used to understand whether ACO racial and ethnic composition was associated with program exit, and how ACOs with a high proportion of beneficaries of racial and ethnic minority groups differed in characteristics associated with program exit.
Exposures: Racial and ethnic composition of an ACO\u27s beneficiaries.
Main Outcomes and Measures: Shared savings program exit before 2018.
Results: The study included 589 Medicare Shared Savings Program ACOs. The ACOs in the highest quartile of proportion of beneficaries of racial and ethnic minority groups were designated high-proportion ACOs (145 [25%]), and those in the lowest 3 quartiles were designated low-proportion ACOs (444 [75%]). In unadjusted analysis, a 10-percentage point increase in the proportion of beneficiaries of racial and ethnic minority groups was associated with a 1.12-fold increase in the odds of an ACO exit (95% CI, 1.00-1.25; P = .04). In adjusted analysis, there were significant associations among high-proportion ACOs between characteristics such as patient comorbidities, disability, and clinician composition and a higher likelihood of exit.
Conclusions and Relevance: The study results suggest that ACOs that served a higher proportion of beneficaries of racial and ethnic minority groups were more likely to exit the Medicare Shared Savings Program, partially because of serving patients with greater disease severity and complexity. These findings raise concerns about how current payment reform efforts may differentially affect racial and ethnic minority groups
Symptomatic Subcapsular and Perinephric Hematoma Following Ureteroscopic Lithotripsy for Renal Calculi
Objective: Ureteroscopic lithotripsy (URSL) is believed to be associated with less risk of symptomatic renal hematoma than extracorporeal shockwave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL). We sought to document the rate of and risk factors for this rare complication following URSL for renal calculi. Methods: With Institutional Review Board approval, we reviewed 1087 cases of URSL performed between July 2009 and October 2012 for four surgeons. We identified cases for renal calculi complicated by symptomatic ?hematoma? by searching electronic medical records of patients undergoing URSL with a web-based search tool and cross-referencing with a departmental quality improvement database for postoperative complications. Chi-squared tests were used to assess risk factors. Results: Among 877 renal units exposed to URSL for renal calculi, 4 were complicated by symptomatic subcapsular hematomas (SH) and 3 by symptomatic perinephric hematomas (PH), yielding a 0.5% and 0.3% rate for each complication, respectively. Pain was the primary presenting symptom. Almost all cases presented within 24 to 48 hours postop. Two PH patients required postoperative blood transfusion. Four patients (two SH, two PH) were hospitalized for observation. Ureteral sheaths were used in two cases (one PH and one SH). There was no association with age, diabetes, body mass index (BMI), or operative duration (p-values all>0.05). However, hematoma did correlate with female gender, preoperative hypertension, preoperative ureteral stenting, intraoperative ureteral sheath use, and postoperative ureteral stenting (all p-values<0.0001). Conclusions: While symptomatic hematoma is a complication of URSL, the rate of such outcome (0.8%) is far less than that reported by prior series with SWL and PCNL. This may partially be attributable to collection biases, where subclinical cases are not imaged, or anchoring biases, where clinicians attribute symptoms to another possible etiology. This outcome can be morbid, but can often be conservatively managed with observation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140379/1/end.2014.0176.pd
- …