Modelling preventive effectiveness to estimate the equity tipping point: at what coverage can individual preventive interventions reduce socioeconomic disparities in diabetes risk?

INTRODUCTION

Most individual preventive therapies potentially narrow or widen health disparities depending on the difference in community effectiveness across socioeconomic position (SEP). The equity tipping point (defined as the point at which health disparities become larger) can be calculated by varying components of community effectiveness such as baseline risk of disease, intervention coverage and/or intervention efficacy across SEP.

METHODS

We used a simple modelling approach to estimate the community effectiveness of diabetes prevention across SEP in Canada under different scenarios of intervention coverage.

RESULTS

Five-year baseline diabetes risk differed between the lowest and highest income groups by 1.76%. Assuming complete coverage across all income groups, the difference was reduced to 0.90% (144 000 cases prevented) with lifestyle interventions and 1.24% (88 100 cases prevented) with pharmacotherapy. The equity tipping point was estimated to be a coverage difference of 30% for preventive interventions (100% and 70% coverage among the highest and lowest income earners, respectively).

CONCLUSION

Disparities in diabetes risk could be measurably reduced if existing interventions were equally adopted across SEP. However, disparities in coverage could lead to increased inequity in risk. Simple modelling approaches can be used to examine the community effectiveness of individual preventive interventions and their potential to reduce (or increase) disparities. The equity tipping point can be used as a critical threshold for disparities analyses.

Social inequality in health, responsibility and egalitarian justice

Are social inequalities in health unjust when brought about by differences in lifestyle? A widespread idea, luck egalitarianism, is that inequality stemming from individuals' free choices is not to be considered unjust, since individuals, presumably, are themselves responsible for such choices. Thus, to the extent that lifestyles are in fact results of free choices, social inequality in health brought about by these choices is not in tension with egalitarian justice. If this is so, then it may put in question the justification of free and equal access to health care and existing medical research priorities. However, personal responsibility is a highly contested issue and in this article we first consider the case for, and second the case against, personal responsibility for health in light of recent developments in philosophical accounts of responsibility and equality. We suggest-but do not fully establish-that at the most fundamental level people are never responsible in such a way that appeals to individuals' own responsibility can justify inequalities in health.

Modulation of neuroblastoma disease pathogenesis by an extensive network of epigenetically regulated microRNAs

MicroRNAs (miRNAs) contribute to the pathogenesis of many forms of cancer, including the pediatric cancer neuroblastoma, but the underlying mechanisms leading to altered miRNA expression are often unknown. Here, a novel integrated approach for analyzing DNA methylation coupled with miRNA and mRNA expression data sets identified 67 epigenetically regulated miRNA in neuroblastoma. A large proportion (42%) of these miRNAs was associated with poor patient survival when underexpressed in tumors. Moreover, we demonstrate that this panel of epigenetically silenced miRNAs targets a large set of genes that are overexpressed in tumors from patients with poor survival in a highly redundant manner. The genes targeted by the epigenetically regulated miRNAs are enriched for a number of biological processes, including regulation of cell differentiation. Functional studies involving ectopic overexpression of several of the epigenetically silenced miRNAs had a negative impact on neuroblastoma cell viability, providing further support to the concept that inactivation of these miRNAs is important for neuroblastoma disease pathogenesis. One locus, miR-340, induced either differentiation or apoptosis in a cell context dependent manner, indicating a tumor suppressive function for this miRNA. Intriguingly, it was determined that miR-340 is upregulated by demethylation of an upstream genomic region that occurs during the process of neuroblastoma cell differentiation induced by all-trans retinoic acid (ATRA). Further biological studies of miR-340 revealed that it directly represses the SOX2 transcription factor by targeting of its 3'-untranslated region, explaining the mechanism by which SOX2 is downregulated by ATRA. Although SOX2 contributes to the maintenance of stem cells in an undifferentiated state, we demonstrate that miR-340-mediated downregulation of SOX2 is not required for ATRA induced differentiation to occur. In summary, our results exemplify the dynamic nature of the miRNA epigenome and identify a remarkable network of miRNA/mRNA interactions that significantly contribute to neuroblastoma disease pathogenesis.

Keeping Australia’s islands free of introduced rodents: the Barrow Island example

Islands are important reservoirs of endemic and threatened species, but anthropogenic influences have impacted their biotas. Australia has over 8000 islands, both continental and oceanic, but because of considerably increased traffic, both tourist and commercial, many of these islands have been and are subject to increased threats from invasive species. The invasive Black Rat Rattus rattus is of particular concern as it can negatively impact mammal, bird, reptile, invertebrate and plant populations. Barrow Island, in northwest Western Australia, is an island requiring particular protection from Black Rats as it is a Class A nature reserve with many unique and threatened taxa that is subject to major disturbances from activities associated with oil extraction and a large liquefied natural gas processing plant. Strict quarantine is currently imposed on all materials and persons being sent to the island and there is an intense on-island surveillance programme. So far the protocols used have prevented Black Rats establishing on this island, but such a level of biosecurity is clearly impossible for all islands. In this paper we discuss the effectiveness of quarantine inspections and surveillance together and alone in protecting high-risk, high-value Australian islands against introduced rodents and we document eradication costs for other islands. World-wide, it has only been possible so far to eradicate rats from relatively small islands, mostly with no non-target indigenous mammals and larger islands only where there are no non-target indigenous mammals. Models based largely on economic considerations have suggested it is more cost effective to use surveillance alone without quarantine for Black Rats on Barrow Island and that if rats become widespread (an estimated 4% risk), it may be more cost effective not to attempt eradication. Such models provide useful guidance for managers where biodiversity values are relatively low or where there are no non-target species, but for Barrow island we argue for continuation of quarantine as well as surveillance and an increased level of quarantine controls at the point of departure on all people, vessels and aircraft visiting other vulnerable Australian islands.

The addition of mesna to hyperhydration does not decrease the incidence of hemorrhagic cystitis in patients receiving high-dose cyclophosphamide

To assess the efficacy of hyperhydration Versus hyperhydration plus mesna in preventing cyclophosphamide induced hemorrhagic cystitis a retrospective analysis was conducted of 110 patients who received hyperhydration alone (baseline intravenous intake of at least 3.6 1/m(2)/day) and 107 patients who received hyperhydration plus mesna (120% of daily cyclophosphamide dose) while receiving cyclophosphamide (total dose 150-200 mg/kg) as part of a dose intensive regimen. Macroscopic hematuria was noted in 17 (16%) and 9 (8%) patients who received hyperhydration with or without mesna, respectively (p=0.08). This analysis failed to demonstrate a benefit in adding mesna to hyperhydration alone in preventing cyclophosphamide induced hemorrhagic cystitis.

Elevated tibiofemoral articular contact stress predicts risk for bone marrow lesions and cartilage damage at 30 months

OBJECTIVE

As cartilage loss and bone marrow lesions (BMLs) are associated with knee joint pain and structural worsening, this study assessed whether non-invasive estimates of articular contact stress may longitudinally predict risk for worsening of knee cartilage morphology and BMLs.

DESIGN

This was a longitudinal cohort study of adults aged 50-79 years with risk factors for knee osteoarthritis. Baseline and follow-up measures included whole-organ magnetic resonance imaging score (WORMS) classification of knee cartilage morphology and BMLs. Tibiofemoral geometry was manually segmented on baseline magnetic resonance imaging (MRI), and three-dimensional (3D) tibiofemoral point clouds were registered into subject-specific loaded apposition using fixed-flexion knee radiographs. Discrete element analysis (DEA) was used to estimate mean and peak contact stresses for the medial and lateral compartments. The association of baseline contact stress with worsening cartilage and BMLs in the same subregion over 30 months was assessed using conditional logistic regression.

RESULTS

Subjects (N = 38, 60.5% female) had a mean ± standard deviation (SD) age and body mass index (BMI) of 63.5 ± 8.4 years and 30.5 ± 3.7 kg/m2 respectively. Elevated mean articular contact stress at baseline was associated with worsening cartilage morphology and worsening BMLs by 30 months, with odds ratio (OR) [95% confidence interval (CI)] of 4.0 (2.5, 6.4) and 6.6 (2.7, 16.5) respectively. Peak contact stress also was significantly associated with worsening cartilage morphology and BMLs {1.9 (1.5, 2.3) and 2.3 (1.5, 3.6)}(all P < 0.0001).

CONCLUSIONS

Detection of higher contact stress 30 months prior to structural worsening suggests an etiological role for mechanical loading. Estimation of articular contact stress with DEA is an efficient and accurate means of predicting subregion-specific knee joint worsening and may be useful in guiding prognosis and treatment.

MicroRNA-204 increases sensitivity of neuroblastoma cells to cisplatin and is associated with a favourable clinical outcome

Background:

Neuroblastoma remains a major cause of cancer-linked mortality in children. miR-204 has been used in microRNA expression signatures predictive of neuroblastoma patient survival. The aim of this study was to explore the independent association of miR-204 with survival in a neuroblastoma cohort, and to investigate the phenotypic effects mediated by miR-204 expression in neuroblastoma.

Methods:

Neuroblastoma cell lines were transiently transfected with miR-204 mimics and assessed for cell viability using MTS assays. Apoptosis levels in cell lines were evaluated by FACS analysis of Annexin V-/propidium iodide-stained cells transfected with miR-204 mimics and treated with chemotherapy drug or vehicle control. Potential targets of miR-204 were validated using luciferase reporter assays.

Results:

miR-204 expression in primary neuroblastoma tumours was predictive of patient event-free and overall survival, independent of established known risk factors. Ectopic miR-204 expression significantly increased sensitivity to cisplatin and etoposide in vitro. miR-204 direct targeting of the 3′ UTR of BCL2 and NTRK2 (TrkB) was confirmed.

Conclusion:

miR-204 is a novel predictor of outcome in neuroblastoma, functioning, at least in part, through increasing sensitivity to cisplatin by direct targeting and downregulation of anti-apoptotic BCL2. miR-204 also targets full-length NTRK2, a potent oncogene involved with chemotherapy drug resistance in neuroblastoma.

Patients' hopes and expectations of a specialist chronic fatigue syndrome/ME service: a qualitative study

BACKGROUND

The 2007 National Institute for Health and Clinical Excellence guidelines on Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) recommend early management of the condition. Investment by the Department of Health has expanded the number of specialist U.K. CFS/ME services but there has been little research on what patients hope or expect from referral.

METHODS

A qualitative study exploring hopes and expectations of patients newly referred to a CFS/ME Service in the South of England. Interviews with 20 patients were analysed using the constant comparative method.

RESULTS

Participants hoped referral to a specialist service would clarify diagnosis, give guidance and support, assist in understanding the complexity of the illness and provide hope for the future. While many participants valued the support of their GP, all viewed referral as offering a level of specialist expertise beyond that available in primary care. Many participants expressed high levels of uncertainty about the nature of CFS/ME. While participants hoped that the service would be able to provide information and guidance, many expressed the view that more information earlier in their illness would make the waiting period less stressful and make it possible for them to do more to help themselves.

CONCLUSIONS

GP referral to a specialist service appeared to be highly valued by the participants in this study. The levels of uncertainty expressed by many patients about the nature of CFS/ME raises the issue of the role of information on CFS/ME during the early stages of the illness and suggests a need for more reassurance and positive advice during the waiting period.