New methods for modelling EQ‐5D‐5L value sets: An application to English data

Value sets for the EQ‐5D‐5L are required to facilitate its use in estimating quality‐adjusted life years. An international protocol has been developed to guide the collection of stated preference data for this purpose and has been used to generate EQ‐5D‐5L valuation data for England. The aim of this paper is report the innovative methods used for modelling those data to obtain a value set. Nine hundred and ninety‐six members of the English general public completed time trade‐off (TTO) and discrete choice experiment (DCE) tasks. We estimate models, with and without interactions, using DCE data only, TTO data only, and TTO/DCE data combined. TTO data are interpreted as both left and right censored. Heteroskedasticity and preference heterogeneity between individuals are accounted for. We use Bayesian methods in the econometric analysis. The final model is chosen based on the deviance information criterion (DIC). Censoring and taking account of heteroskedasticity have important effects on parameter estimation. For DCE data only, TTO data only, and DCE/TTO data combined, models with parameters for all dimensions and levels perform best, as judged by the DIC. Taking account of heterogeneity improves fit, and the multinomial model reports the lowest DIC. This paper presents approaches that suit observed characteristics of EQ‐5D‐5L valuation data and recognise respondents' preference heterogeneity. The methods described are potentially relevant to other value set studies.     

Family physician remuneration schemes and specialist referrals: Quasi‐experimental evidence from Ontario,Canada

Understanding how family physicians respond to incentives from remuneration schemes is a central theme in the literature. One understudied aspect is referrals to specialists. Although the theoretical literature has suggested that capitation increases referrals to specialists, the empirical evidence is mixed. We push forward the empirical research on this question by studying family physicians who switched from blended fee‐for‐service to blended capitation in Ontario, Canada. Using several health administrative databases from 2005 to 2013, we rely on inverse probability weighting with fixed‐effects regression models to account for observed and unobserved differences between the switchers and nonswitchers. Switching from blended fee‐for‐service to blended capitation increases referrals to specialists by about 5% to 7% per annum. The cost of specialist referrals is about 7 to 9% higher in the blended capitation model relative to the blended fee‐for‐service. These results are generally robust to a variety of alternative model specifications and matching techniques, suggesting that they are driven partly by the incentive effect of remuneration. Policy makers need to consider the benefits of capitation payment scheme against the unintended consequences of higher referrals to specialists.     

Valuation of EuroQol Five-Dimensional Questionnaire,Youth Version (EQ-5D-Y) and EuroQol Five-Dimensional Questionnaire,Three-Level Version (EQ-5D-3L) Health States: The Impact of Wording and Perspective

Background

Valuations of health states were affected by the wording of the two instruments (EQ-5D-3L and EQ-5D-Y) and by the perspective taken (child or adult).

Genetic alterations of IL-1 receptor antagonist in mice affect plasma cholesterol level and foam cell lesion size

Inflammatory cytokines have been linked to atherosclerosis by using cell culture models and acute inflammation in animals. The goal of this study was to examine lipoprotein levels and early atherosclerosis in chronic animal models of altered IL-1 physiology by using mice with deficient or excess IL-1 receptor antagonist (IL-1ra). IL-1ra knockout C57BL/6J mice fed a cholesterol/cholate diet for 3 mo had a 3-fold decrease in non-high-density lipoprotein cholesterol and a trend toward increased foam-cell lesion area compared to wild-type littermate controls. IL-1ra transgenic/low-density lipoprotein receptor (LDLR) knockout mice fed a cholesterol-saturated fat diet for 10 wk showed a 40% increase in non-high-density lipoprotein cholesterol, consistent with the IL-1ra knockout data, although there was no change in lesion size. When these IL1-ra overexpressing transgenic mice on the LDLR knockout background were fed a high-cholesterol/high-fat diet containing cholate, however, a statistically significant 40% decrease in lesion area was observed compared to LDLR knockout mice lacking the transgene. By immunohistochemistry, IL-1ra was present in C57BL/6J and LDLR knockout aortae, absent in IL-1ra knockout aortae, and present at high levels in LDLR knockout/IL-1ra transgene aortae. In summary, IL-1ra tended to increase plasma lipoprotein levels and, when fed a cholate-containing diet, decrease foam-cell lesion size. These data demonstrate that in selected models of murine atherosclerosis, chronic IL-1ra depletion or overexpression has potentially important effects on lipoprotein metabolism and foam-cell lesion development.     

Lack of class I H-2 antigens in cells transformed by radiation leukemia virus is associated with methylation and rearrangement of H-2 DNA

Transformation of murine thymocytes by radiation leukemia virus is associated with reduced expression of the class I antigens encoded in the major histocompatibility complex (MHC) and increased methylation and altered restriction enzyme patterns of MHC DNA. These changes may play a role in host susceptibility to virus-induced leukemogenesis and accord with the notion that viral genomes play a regulatory function when they integrate adjacent to histocompatibility genes.     

Changes in IGFs in cardiac tissue following myocardial infarction

We have studied changes in the IGF axis in an ovine model of myocardial infarction (MI), in order to determine the relationship between time-based changes in post-infarct myocardium and IGF levels. IGF localization was studied by immunocytochemistry, production by in situ hybridization, and specific binding by radioligand studies. In surviving tissue, IGF-I peptide localized to cardiomyocytes, with strongest immunostaining at 1 and 2 days post-infarct in the immediate border area adjoining the infarct, where IGF-I mRNA also increased, reaching a maximum at 2 days. Binding of radiolabelled IGF-I in surviving tissue was initially lower than that seen in cardiomyocytes in control myocardium, subsequently increasing to become significantly greater by 6 days post-infarct. In necrotic tissue, IGF-I peptide was still detectable in cardiomyocytes at 0.5 days post-infarct, but had cleared from this area by 1 day, becoming detectable again at 6 days post-infarct in macrophages and fibroblasts infiltrating the repair zone. IGF-I mRNA was not detected in necrotic tissue until 6 days, when probe hybridized to macrophages and fibroblasts. Within the necrotic zone, high levels of radiolabelled IGF-I binding to a combination of receptors and binding proteins were observed in cardiomyocytes in islands of viable tissue located close to the border. Weak immunostaining for IGF-II was observed in cardiomyocytes of the surviving tissue. IGF-II mRNA was not detected in either surviving or necrotic areas. Binding of radiolabelled IGF-II was predominantly to macrophages in both surviving and infarct areas, although as with IGF-I, high levels of binding of radiolabelled IGF-II to a combination of receptors and binding proteins were observed in islands of viable tissue close to the border within the necrotic area. We conclude that, following MI, surviving cardiomyocytes at the infarct border show marked changes in IGF-I localization, production, and specific binding, indicating that the IGF axis is directly involved in post-infarct events, possibly in the maintenance of cardiac function by the induction of hypertrophy and in cell survival by decreasing apoptotic cell death, which has been demonstrated in other cell types.     

[4Fe-4S]-cluster-depleted Azotobacter vinelandii ferredoxin I: a new 3Fe iron-sulfur protein.

Fe(CN)6(-3) oxidation of the aerobically isolated 7Fe Azotobacter vinelandii ferredoxin I, (7Fe)FdI, is a degradative reaction. Destruction of the [4Fe-4S] cluster occurs first, followed by destruction of the [3Fe-3S] cluster. At a Fe(CN)6(-3)/(7Fe)FdI concentration ratio of 20, the product is a mixture of apoprotein and protein containing only a [3Fe-3S] cluster, (3Fe)FdI. This protein mixture, after partial purification, has been characterized by absorption, CD, magnetic CD, and EPR and Fe x-ray absorption spectroscopies. EPR and magnetic CD spectra provide strong evidence that the [3Fe-3S] cluster in (3Fe)FdI is essentially identical in structure to that in (7Fe)FdI. Analysis of the extended x-ray absorption fine structure (EXAFS) of (3Fe)FdI finds Fe scattering at an average Fe...Fe distance of approximately equal to 2.7 A. The structure of the oxidized [3Fe-3S] cluster in solutions of oxidized (3Fe)FdI, and, by extension, of oxidized (7Fe)FdI, is thus different from that obtained by x-ray crystallography on oxidized (7Fe)FdI. Possible interpretations of this result are discussed.     

Which patients stop working because of rheumatoid arthritis? Results of five years' follow up in 732 patients from the Early RA Study (ERAS)

OBJECTIVES: To assess the occurrence and prognostic factors for the ability to maintain paid work in patients with rheumatoid arthritis (RA). SETTING: Inception cohort of patients with RA recruited from rheumatology departments in nine NHS Hospital Trusts in England. PATIENTS: All consecutive patients with RA of less than two years' duration, before any second line (disease modifying) drug treatment, and followed up for five years. METHODS: Clinical, laboratory, and radiological assessments, and all treatments were recorded prospectively using a standardised format at presentation and yearly. OUTCOME MEASURES: Changes in, and loss of paid work by five years' follow up. RESULTS: 732 patients completed the five year follow up. 353/721 (49%) were gainfully employed at the onset of RA, 211 (60%) were still working at five years, 104 (29%) stopped because of the disease, and 31 (9%) retired for reasons other than RA. Work disability at five years was more likely in manual workers (odds ratio (OR) 2.3, 95% confidence interval (CI) 1.4 to 3.8) and worse baseline Health Assessment Questionnaire (HAQ>1.5, OR 2.26, 95% CI 1.38 to 3.7). In combination with other baseline variables (erythrocyte sedimentation rate, sex, age of onset, and radiological erosions), employment outcome was predicted in 78% using multivariate analysis. CONCLUSIONS: Nearly half of the patients with RA were in paid employment at onset, work disability was an adverse outcome for a third of these patients by five years, and manual work and high baseline HAQ were important predictors for this. These details are likely to be useful to clinicians, health professionals, and patients in order to plan medical, orthopaedic, and remedial treatments in early RA. Future disease modifying treatments could be compared with this cohort of patients who were treated with conventional second line drugs.