A Risk-Adjusted Model for Ovarian Cancer Care and Disparities in Access to High-Performing Hospitals.

ObjectiveTo validate the observed/expected ratio for adherence to ovarian cancer treatment guidelines as a risk-adjusted measure of hospital quality care, and to identify patient characteristics associated with disparities in access to high-performing hospitals.MethodsThis was a retrospective population-based study of stage I-IV invasive epithelial ovarian cancer reported to the California Cancer Registry between 1996 and 2014. A fit logistic regression model, which was risk-adjusted for patient and disease characteristics, was used to calculate the observed/expected ratio for each hospital, stratified by hospital annual case volume. A Cox proportional hazards model was used for survival analyses, and a multivariable logistic regression model was used to identify independent predictors of access to high-performing hospitals.ResultsThe study population included 30,051 patients who were treated at 426 hospitals: low observed/expected ratio (n=304) 23.5% of cases; intermediate observed/expected ratio (n=92) 57.8% of cases; and high observed/expected ratio (n=30) 18.7% of cases. Hospitals with high observed/expected ratios were significantly more likely to deliver guideline-adherent care (53.3%), compared with hospitals with intermediate (37.8%) and low (27.5%) observed/expected ratios (P<.001). Median disease-specific survival time ranged from 73.0 months for hospitals with high observed/expected ratios to 48.1 months for hospitals with low observed/expected ratios (P<.001). Treatment at a hospital with a high observed/expected ratio was an independent predictor of superior survival compared with hospitals with intermediate (hazard ratio [HR] 1.06, 95% CI 1.01-1.11, P<.05) and low (HR 1.10, 95% CI 1.04-1.16, P<.001) observed/expected ratios. Being of Hispanic ethnicity (odds ratio [OR] 0.85, 95% CI 0.78-0.93, P<.001, compared with white), having Medicare insurance (OR 0.74, 95% CI 0.68-0.81 P<.001, compared with managed care), having a Charlson Comorbidity Index score of 2 or greater (OR 0.91, 95% CI 0.83-0.99, P<.05), and being of lower socioeconomic status (lowest quintile OR 0.41, 95% CI 0.36-0.46, P<.001, compared with highest quintile) were independent negative predictors of access to a hospital with a high observed/expected ratio.ConclusionOvarian cancer care at a hospital with a high observed/expected ratio is an independent predictor of improved survival. Barriers to high-performing hospitals disproportionately affect patients according to sociodemographic characteristics. Triage of patients with suspected ovarian cancer according to a performance-based observed/expected ratio hospital classification is a potential mechanism for expanded access to expert care

Stress-Induced Variations in the Stiffness of Micro- and Nanocantilever Beams

The effect of surface stress on the stiffness of cantilever beams remains an outstanding problem in the physical sciences. While numerous experimental studies report significant stiffness change due to surface stress, theoretical predictions are unable to rigorously and quantitatively reconcile these observations. In this Letter, we present the first controlled measurements of stress-induced change in cantilever stiffness with commensurate theoretical quantification. Simultaneous measurements are also performed on equivalent clamped-clamped beams. All experimental results are quantitatively and accurately predicted using elasticity theory. We also present conclusive experimental evidence for invalidity of the longstanding and unphysical axial force model, which has been widely applied to interpret measurements using cantilever beams. Our findings will be of value in the development of micro- and nanoscale resonant mechanical sensors

Valoración de las pérdidas sanguíneas en cirugía protésica primaria de cadera: estudio comparativo entre abordaje posterolateral y lateral

La artroplastia total de cadera se caracteriza por una pérdida sanguínea considerable. El propósito de nuestro estudio es valorar si existen diferencias en las pérdidas sanguíneas perioperatorias esperadas en prótesis totales de cadera (PTC) según el abordaje utilizado. Se planificó un estudio prospectivo en 33 pacientes divididos en dos grupos en función del abordaje utilizado: Grupo A abordaje posterolateral y grupo B abordaje lateral de Hardinge. El análisis de los datos recogidos no mostraba diferencias significativas ni en las pérdidas sanguíneas totales (p-0,4881), ni en los descensos de hemoglobina (p-0,6707), ni de hematocrito (p-0,9416).Blood loss in primary total hip arthroplasty is important. The aim of our research is to study if there are differences between blood losses in total hip replacement according to the surgical approach used. We have designed a prospective study in 33 patients divided into two groups depending on surgical approach: Group A posterolateral approach and group B Hardinge ́s lateral approach. The results show no difference either in total blood loss (P-0,4881) or in hemoglobine decrease (P-0,6707) and hematocrite decrease (P-0,9416)