Cost-effectiveness of human leukocyte antigen matching in penetrating keratoplasty

Background: The matching of favorable human leukocyte antigen (HLA) combinations is rarely performed in penetrating keratoplasty procedures for primary prophylaxis of immune reactions. However, clinical studies suggest that the incidence of graft rejection decreases substantially when patients receive favorably matched grafts. Objective: The aim of this study was to assess the cost-effectiveness of HLA matching for patients undergoing penetrating keratoplasty in everyday clinical practice. Methods: In the absence of a randomized controlled clinical trial, we used administrative data from the Freiburg University Eye Hospital in Germany. Our study population consisted of all patients who underwent their first keratoplasty between 11/2003 and 01/2010 and for whom information on HLA histocompatibility was available. We used propensity score matching to estimate a causal effect of favorable HLA matching, parametric survival regression techniques to predict graft survival and expert opinion to model incremental cost for HLA matching. Because the availability of favorable HLA histocompatibility ultimately depends on the patients’ HLA phenotype, we modeled the incremental cost-effectiveness ratio (ICER) as a function of the probability that a patient will receive a favorably matched HLA, and used expert opinion to set a point estimate. Results: We predicted that corneal grafts with favorable HLA matching were associated with improved rejection-free graft survival time (more than 1,000 days). We estimated the incremental cost of HLA matching at EUR 1,200 and the ICER at EUR 4.62 per additional day of graft survival. Conclusions: The ICER of HLA matching is acceptable, given the high cost of alternative treatment and the shortage of corneal donors in Germany

Attitudes Concerning Postmortem Organ Donation : A Multicenter Survey in Various German Cohorts

BACKGROUND The aim of this study was to characterize postmortem organ donation attitudes in various German cohorts. MATERIAL AND METHODS Employees of 2 German cities and 2 German university hospitals, employees of a German automobile enterprise, and members of a German Medical Society were administered a questionnaire about postmortem organ and tissue donation attitudes. Demographic data and general attitudes were questioned and focused on: I) willingness to donate organs, II) holding a donor card, and III) having discussed the topic with the family. RESULTS Of 5291 participants, 65.2% reported favoring postmortem organ donation. Missing negative experiences, the idea that donation is helpful, a non-medical professional environment, excellent general health, gender, agreement with the brain-death paradigm, and age significantly influenced the participants’ attitudes. Participants were more likely to possess donor cards and had discussed more often with family members if they agreed with the brain-death paradigm and considered donation to be helpful. Males and older participants were the most likely to neglect donor cards, and Catholics, Protestants, and participants with poor health were the least likely to donate organs. Interest in receiving more information was expressed by 38.1% and 50.6% of participants refusing donation of all or of specific organs, respectively, and suggested the internet (60.0%) and family doctors (35.0%) as preferred sources of information. CONCLUSIONS Public campaigns in Germany should focus on males and older people as regards donor cards, and females, younger, and religiously affiliated persons as regards the general willingness to donate organs postmortem

The HYLAN M Study: Efficacy of 0.15% High Molecular Weight Hyaluronan Fluid in the Treatment of Severe Dry Eye Disease in a Multicenter Randomized Trial

The aim of the HYLAN M study was to investigate if symptoms and/or signs of patients suffering from severe dry eye disease (DED) can be improved by substituting individually optimized artificial tear therapy by high molecular weight hyaluronan (HMWHA) eye drops. In this international, multicenter study, patients with symptoms of at least ocular surface disease index (OSDI) 33 and corneal fluorescein staining (CFS) of at least Oxford grade 3 were included. A total of 84 per-protocol patients were randomized in two study arms. The control group continued to use their individual optimum artificial tears over the study period of eight weeks; in the verum group, the artificial tears were substituted by eye drops containing 0.15% HMWHA. At the week 8 visit, the average OSDI of the verum group had improved by 13.5 as compared to the control group (p = 0.001). The best corrected visual acuity (BCVA) had improved by 0.04 logMAR (p = 0.033). CFS, tear film break-up time (TBUT), Schirmer I, lid wiper epitheliopathy (LWE), mucocutaneous junction (Yamaguchi score), and tear osmolarity were not significantly different between the verum and control groups (p > 0.050). We conclude that for most patients with severe DED, 0.15% HMWHA eye drops provide excellent improvement of symptoms without impairment of dry eye signs

The Observed Growth of Massive Galaxy Clusters III: Testing General Relativity on Cosmological Scales

This is the third of a series of papers in which we derive simultaneous constraints on cosmological parameters and X-ray scaling relations using observations of the growth of massive, X-ray flux-selected galaxy clusters. Our data set consists of 238 clusters drawn from the ROSAT All-Sky Survey, and incorporates extensive follow-up observations using the Chandra X-ray Observatory. Here we present improved constraints on departures from General Relativity (GR) on cosmological scales, using the growth index, gamma, to parameterize the linear growth rate of cosmic structure. Using the method of Mantz et al. (2009a), we simultaneously and self-consistently model the growth of X-ray luminous clusters and their observable-mass scaling relations, accounting for survey biases, parameter degeneracies and systematic uncertainties. We combine the cluster growth data with gas mass fraction, SNIa, BAO and CMB data. This combination leads to a tight correlation between gamma and sigma_8. Consistency with GR requires gamma~0.55. Under the assumption of self-similar evolution and constant scatter in the scaling relations, and for a flat LCDM model, we measure gamma(sigma_8/0.8)^6.8=0.55+0.13-0.10, with 0.79<sigma_8<0.89. Relaxing the assumptions on the scaling relations by introducing two additional parameters to model possible evolution in the normalization and scatter of the luminosity-mass relation, we obtain consistent constraints on gamma that are only ~20% weaker than those above. Allowing the dark energy equation of state, w, to take any constant value, we simultaneously constrain the growth and expansion histories, and find no evidence for departures from either GR or LCDM. Our results represent the most robust consistency test of GR on cosmological scales to date. (Abridged)Comment: Accepted for publication in MNRAS. 11 pages, 5 figures, 1 table. New figure added: Fig. 4 shows the tight constraints on gamma from the cluster growth data alone compared with those from the other data sets combined

Multimodality in galaxy clusters from SDSS DR8: substructure and velocity distribution

We search for the presence of substructure, a non-Gaussian, asymmetrical velocity distribution of galaxies, and large peculiar velocities of the main galaxies in galaxy clusters with at least 50 member galaxies, drawn from the SDSS DR8. We employ a number of 3D, 2D, and 1D tests to analyse the distribution of galaxies in clusters: 3D normal mixture modelling, the Dressler-Shectman test, the Anderson-Darling and Shapiro-Wilk tests and others. We find the peculiar velocities of the main galaxies, and use principal component analysis to characterise our results. More than 80% of the clusters in our sample have substructure according to 3D normal mixture modelling, the Dressler-Shectman (DS) test shows substructure in about 70% of the clusters. The median value of the peculiar velocities of the main galaxies in clusters is 206 km/s (41% of the rms velocity). The velocities of galaxies in more than 20% of the clusters show significant non-Gaussianity. While multidimensional normal mixture modelling is more sensitive than the DS test in resolving substructure in the sky distribution of cluster galaxies, the DS test determines better substructure expressed as tails in the velocity distribution of galaxies. Richer, larger, and more luminous clusters have larger amount of substructure and larger (compared to the rms velocity) peculiar velocities of the main galaxies. Principal component analysis of both the substructure indicators and the physical parameters of clusters shows that galaxy clusters are complicated objects, the properties of which cannot be explained with a small number of parameters or delimited by one single test. The presence of substructure, the non-Gaussian velocity distributions, as well as the large peculiar velocities of the main galaxies, shows that most of the clusters in our sample are dynamically young.Comment: 15 pages, 11 figures, 2 online tables, accepted for publication in Astronomy and Astrophysic