Managing structural uncertainty in health economic decision models: a discrepancy approach

Healthcare resource allocation decisions are commonly informed by computer model predictions of population mean costs and health effects. It is common to quantify the uncertainty in the prediction due to uncertain model inputs, but methods for quantifying uncertainty due to inadequacies in model structure are less well developed. We introduce an example of a model that aims to predict the costs and health effects of a physical activity promoting intervention. Our goal is to develop a framework in which we can manage our uncertainty about the costs and health effects due to deficiencies in the model structure. We describe the concept of `model discrepancy': the difference between the model evaluated at its true inputs, and the true costs and health effects. We then propose a method for quantifying discrepancy based on decomposing the cost-effectiveness model into a series of sub-functions, and considering potential error at each sub-function. We use a variance based sensitivity analysis to locate important sources of discrepancy within the model in order to guide model refinement. The resulting improved model is judged to contain less structural error, and the distribution on the model output better reflects our true uncertainty about the costs and effects of the intervention

Social inclusion and valued roles : a supportive framework

The aim of this paper is to examine the concepts of social exclusion, social inclusion and their relevance to health, well-being and valued social roles. The article presents a framework, based on Social Role Valorization (SRV), which was developed initially to support and sustain socially valued roles for those who are, or are at risk of, being devalued within our society. The framework incorporates these principles and can be used by health professionals across a range of practice, as a legitimate starting point from which to support the acquisition of socially valued roles which are integral to inclusio

Tracking and modelling prices using web-scraped price microdata : towards automated daily consumer price index forecasting

With the increasing relevance and availability of on-line prices that we see today, it is natural to ask whether the prediction of the consumer price index (CPI), or related statistics, may usefully be computed more frequently than existing monthly schedules allow for. The simple answer is ‘yes’, but there are challenges to be overcome first. A key challenge, addressed by our work, is that web-scraped price data are extremely messy and it is not obvious, a priori, how to reconcile them with standard CPI statistics. Our research focuses on average prices and disaggregated CPI at the level of product categories (lager, potatoes, etc.) and develops a new model that describes the joint time evolution of latent daily log-inflation rates driving prices seen on the Internet and prices recorded in official surveys, with the model adapting to various product categories. Our model reveals the differing levels of dynamic behaviour across product category and, correspondingly, differing levels of predictability. Our methodology enables good prediction of product-category-specific CPI immediately before their release. In due course, with increasingly complete web-scraped data, combined with the best survey data, the prospect of more frequent intermonth aggregated CPI prediction is an achievable goal

Analyzing clinical trial outcomes based on incomplete daily diary reports

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/122440/1/sim6890.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122440/2/sim6890-sup-0001-supplementary.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/122440/3/sim6890_am.pd

Trials and tribulations : the 'use' (and 'misuse') of evidence in public policy

Randomized controlled trials (RCTs) are increasingly playing a central role in shaping policy for development. By comparison, social experimentation has not driven the great transformation of welfare within the developed world. This introduces a range of issues for those interested in the nature of research evidence for making policy. In this article we will seek a greater understanding of why the RCT is increasingly seen as the ‘gold standard’ for policy experiments in low- and middle-income countries (LMICs), but not in the more advanced liberal democracies, and we will explore the implications of this. One objection to the use of RCTs, however can be cost, but implementing policies and programmes without good evidence or a good understanding of their effectiveness is unlikely to be a good use of resources either. Other issues arise. Trials are often complex to run and ethical concerns often arise in social ‘experiments’ with human subjects. However, rolling out untested policies may also be morally objectionable. This article sheds new light on the relationship between evidence and evaluation in public policy in both the global north and developing south. It also tackles emerging issues concerning the ‘use’ and ‘misuse’ of evidence and evaluation within public policy

Genome-Wide Association Studies of Grain Yield Components in Diverse Sorghum Germplasm

Citation: Boyles, R. E., Cooper, E. A., Myers, M. T., Brenton, Z., Rauh, B. L., Morris, G. P., & Kresovich, S. (2016). Genome-Wide Association Studies of Grain Yield Components in Diverse Sorghum Germplasm. Plant Genome, 9(2), 17. doi:10.3835/plantgenome2015.09.0091Grain yield and its primary determinants, grain number and weight, are important traits in cereal crops that have been well studied; however, the genetic basis of and interactions between these traits remain poorly understood. Characterization of grain yield per primary panicle (YPP), grain number per primary panicle (GNP), and 1000-grain weight (TGW) in sorghum [Sorghum bicolor (L.) Moench], a hardy C-4 cereal with a genome size of similar to 730 Mb, was implemented in a diversity panel containing 390 accessions. These accessions were genotyped to obtain 268,830 single-nucleotide polymorphisms (SNPs). Genome-wide association studies (GWAS) were performed to identify loci associated with each grain yield component and understand the genetic interactions between these traits. Genome-wide association studies identified associations across the genome with YPP, GNP, and TGW that were located within previously mapped sorghum QTL for panicle weight, grain yield, and seed size, respectively. There were no significant associations between GNP and TGW that were within 100 kb, much greater than the average linkage disequilibrium (LD) in sorghum. The identification of nonoverlapping loci for grain number and weight suggests these traits may be manipulated independently to increase the grain yield of sorghum. Following GWAS, genomic regions surrounding each associated SNP were mined for candidate genes. Previously published expression data indicated several TGW candidate genes, including an ethylene receptor homolog, were primarily expressed within developing seed tissues to support GWAS. Furthermore, maize (Zea mays L.) homologs of identified TGW candidates were differentially expressed within the seed between small- and large-kernel lines from a segregating maize population

Ebola virus disease in the Democratic Republic of the Congo, 1976-2014.

The Democratic Republic of the Congo has experienced the most outbreaks of Ebola virus disease since the virus' discovery in 1976. This article provides for the first time a description and a line list for all outbreaks in this country, comprising 996 cases. Compared to patients over 15 years old, the odds of dying were significantly lower in patients aged 5 to 15 and higher in children under five (with 100% mortality in those under 2 years old). The odds of dying increased by 11% per day that a patient was not hospitalised. Outbreaks with an initially high reproduction number, R (>3), were rapidly brought under control, whilst outbreaks with a lower initial R caused longer and generally larger outbreaks. These findings can inform the choice of target age groups for interventions and highlight the importance of both reducing the delay between symptom onset and hospitalisation and rapid national and international response

Adopting a family approach to theory and practice: measuring distress in cancer patient-partner dyads with the distress thermometer

Objective: Significant others are central to patients' experience and management of their cancer illness. Building on our validation of the Distress Thermometer (DT) for family members, this investigation examines individual and collective distress in a sample of cancer patients and their matched partners, accounting for the aspects of gender and role.Method: Questionnaires including the DT were completed by a heterogeneous sample of 224 couples taking part in a multisite study.Results: Our investigation showed that male patients (34.2%), female patients (31.9%), and male partners (29.1%) exhibited very similar levels of distress, while female partners (50.5%) exhibited much higher levels of distress according to the DT. At the dyad level just over half the total sample contained at least one individual reporting significant levels of distress. Among dyads with at least one distressed person, the proportion of dyads where both individuals reported distress was greatest (23.6%). Gender and role analyses revealed that males and females were not equally distributed among the four categories of dyads (i.e. dyads with no distress; dyads where solely the patient or dyads where solely the partner is distressed; dyads where both are distressed).Conclusion: A remarkable number of dyads reported distress in one or both partners. Diverse patterns of distress within dyads suggest varying risks of psychosocial strain. Screening patients' partners in addition to patients themselves may enable earlier identification of risk settings. The support offered to either member of such dyads should account for their role- and gender-specific needs. Copyright © 2010 John Wiley & Sons, Ltd

Pollination by the locally endangered island flying fox (Pteropus hypomelanus) enhances fruit production of the economically important durian (Durio zibethinus)

Fruit bats provide valuable pollination services to humans through a unique coevolutionary relationship with chiropterophilous plants. However, chiropterophily in the Old World and the pollination roles of large bats, such as flying foxes (Pteropus spp., Acerodon spp., Desmalopex spp.), are still poorly understood and require further elucidation. Efforts to protect these bats have been hampered by a lack of basic quantitative information on their role as ecosystem service providers. Here, we investigate the role of the locally endangered island flying fox Pteropus hypomelanus in the pollination ecology of durian (Durio zibethinus), an economically important crop in Southeast Asia.On Tioman Island, Peninsular Malaysia, we deployed 19 stations of paired infrared camera and video traps across varying heights at four individual flowering trees in a durian orchard. We detected at least nine species of animal visitors, but only bats had mutualistic interactions with durian flowers. There was a clear vertical stratification in the feeding niches of flying foxes and nectar bats, with flying foxes feeding at greater heights in the trees. Flying foxes had a positive effect on mature fruit set and therefore serve as important pollinators for durian trees. As such, semi-wild durian trees—particularly tall ones—may be dependent on flying foxes for enhancing reproductive success. Our study is the first to quantify the role of flying foxes in durian pollination, demonstrating that these giant fruit bats may have far more important ecological, evolutionary, and economic roles than previously thought. This has important implications and can aid efforts to promote flying fox conservation, especially in Southeast Asian countries