What, who and when? Incorporating a discrete choice experiment into an economic evaluation

Acknowledgements The Medman study was funded by the Department of Health for England and Wales and managed by a collaboration of the National Pharmaceutical Association, the Royal Pharmaceutical Society of Great Britain, the Company Chemist Association and the Co-operative Pharmacy Technical Panel, led by the Pharmaceutical Services Negotiating Committee. The research in this paper was undertaken while the lead author MT was undertaking a doctoral research fellowship jointly funded by the Economic and Social Research Council (ESRC) and the Medical Research Council (MRC). The Health Economics Research Unit (HERU), University of Aberdeen is funded by the Chief Scientific Office of the Scottish Government Health and Social Care Directorate.Peer reviewedPublisher PD

Modelling Heterogeneity and Uncertainty in Contingent Valuation : an Application to the Valuation of Informal Care

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Messy Data Modelling in Health Care Contingent Valuation Studies

This study addresses the complexity in modeling contingent valuation surveys with true zeros and non-ignorable missing responses including “don’t knows†and protest responses. An endogenous switching tobit model is specified to simultaneously estimate the parameters of the latent willingness to pay (WTP) decision variable and the latent true WTP level. A Bayesian technique is developed using MCMC methods data augmentation and Metropolis Hastings algorithm with Gibbs sampling for estimating the endogenous switching tobit model. The Bayesian approach presented here is useful even for finite sample size and for models with relatively flat likelihood like sample selection models for which convergence is a problem or even if convergence is achieved correlation of the latent random errors are outside the (-1,1) range. The proposed methodology is applied to a single-bounded dichotomous choice contingent valuation model using British Eurowill data on evaluating cancer health care program. Results in this study reveal that the interview interest scores for the unresolved or missing cases are substantially high and not far from scores of “yes†respondents. The pattern in the values of socio-economic and health related variables shows that these unresolved cases are not missing completely at random so that they may actually contain valuable information at least on the willingness decision process of respondents. Inclusion of these unresolved cases is essential to modelling WTP decision and true WTP level as reflected in the higher sum of log conditional predictive ordinate(SLCPO) goodness-of-fit criterion for a cross-validation sample and higher covariance between the latent random errors of the latent self-selection or WTP decision variable and the true WTP level model. The positive covariance and correlation of the latent random errors may explain why the true WTP levels in DC contingent valuation studies are oftentimes overestimated. The model presented in this paper may also be applied to double bounded dichotomous choice models with slight modification.non-ignorable missing values, single-bounded dichotomous choice contingent valuation studies,Markov chain Monte Carlo methods

Serratia marcescens, the “Flame” Strain: The Genesis of a New Variant A Newly Described Strain with Prolific Pigment Produced at High Temperature

Serratia marcescens, a Gram-negative, rod-shaped, facultative anaerobe (Fig. 1), is ubiquitous in water, soil, and natural settings. It is easily grown in the lab and may serve as an ideal model for adaptation studies because of the natural color variation of S. marcescens (Gillen 2008). In this paper, we describe a new variant with prolific pigment (prodigiosin) production at high temperatures. In the wild and in buildings, S. marcescens is noted for the production of a bright red pigment called prodigiosin (Williams 1973). We have found a new strain that appears to have adapted to a relatively new pond system called Liberty Library Lake. It produces pigment up to 40°C without any enrichment to media. Most wild-type strains, like NIMA, produce pigment normally up to 30°C, but with extensive enrichment, wild-type strains can produce pigment up to 40°C. This new strain, called the “Flame” strain, not only produces prodigiosin to 39–40°C but also in higher abundance at 35°C and at a brighter hue. NIMA strains can produce pigment at 39–40°C with Serratia Synergy Agar (glycerol, peptone, agar) but not on TSA nor any common agar. It takes significant enhancement for any other Serratia marcescens strains to produce pigment even at 35°C. The Flame strain’s brief appearance in a local, small lake appears to be a phenotypic diversification and adaptation to an environmental perturbation this past school year. The environmental stress prior to its appearance was an autumn drought. Eventually, heavy rainfall occurred and the new strain was discovered. Its appearance coincided with an unusually high abundance of coliforms, avian Giardia, and Cryptosporidium, along with chemical treatment of the lake. The unusual conditions seem to favor a rapid phenotypic diversification and adaptation. The new strain still retains the pigment production at nearly 10°C higher for “normal” prodigiosin production by wild-type Serratia marcescens. This genesis of this new strain seems to have occurred as special conditions favored this new variant. It may be closer to a “proto-type” (ancestral) strain than to more common wild-type strains, like NIMA and BS303. It appears that most wild-type strains, like NIMA and BS303, may have lost this information over time since added enrichment is necessary to produce pigment at 39–40°C. The unusual conditions may have selected for this newly adapted strain to be common for a short time. Also as conditions returned to “normal,” a common wild-type strain reappeared at the local lake, and the Flame strain was no longer found. The objective of this article is to explain the mysterious origin of a new strain of Serratia marcescens that produces prodigiosin up to 40°C without any enrichment to media. This strain can naturally produce prolific pigment that is a bright, flame-red. Since Serratia marcescens offers protection from other microbes, UV light, and drought, it is a wonderful example of intelligent design commonly seen in the microbial world

Keeping an eye on cost : what can eye tracking tell us about attention to cost information in discrete choice experiments?

The University of Aberdeen and the Chief Scientist Office of the Scottish Government Health and Social Care Directorates fund the Health Economics Research Unit (HERU). We thank all participants who took part in the study, Alison Findlay for help with data collection, HESG participants, the editor, anonymous reviewers, and Dr Frouke Hermens for helpful comments and suggestions on the paper. The information and views set out in the article are those of the authors.Peer reviewedPublisher PD

To pay or not to pay? : Cost information processing in the valuation of publicly funded healthcare

Acknowledgments We thank all participants who took part in the study and three anonymous reviewers for their comments on the paper. The design of the discrete choice experiment on which this paper draws was shaped by a team that included, alongside two of the authors, Professor Chris Burton, Professor Vikki Entwistle, Professor Christine Bond, Dr Terry Porteous and Dr Alison Elliott. Funding sources The original DCE study was funded by the Health Foundation. This work has been funded by the University of Aberdeen and the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. These sponsors were not involved in the study design, data analysis and writing of the article. The information and views set out in the article are those of the authors.Peer reviewedPostprin

Weighting or aggregating? Investigating information processing in multi‐attribute choices

ACKNOWLEDGMENTS The design of the choice experiment on which this paper draws was shaped by a team that included, alongside two of the authors, Professor Chris Burton, Professor Vikki Entwistle, Dr Terry Porteous and Dr Alison Elliott. The original CE study was funded by the Health Foundation. The University of Aberdeen and the Chief Scientist Office of the Scottish Government Health and Social Care Directorates fund the Health Economics Research Unit (HERU). The kidney transplantation choice experiment study was funded by the “Progetto di Ateneo KIDNEY” from the University of Padua (Italy). We would like to thank Daniel Rigby (The University of Manchester), Jürgen Maurer (Université de Lausanne), Giacomo Pasini (Ca' Foscari University of Venice), and Luca Corazzini (Ca' Foscari University of Venice) for their helpful comments. Funding: Health Foundation. Grant Number: THF 7264Peer reviewedPublisher PD

Exploring doctors’ trade-offs between management, research, and clinical training in the medical curriculum : a protocol for a discrete choice experiment in Southern Africa

Funding This work was supported by the Department of Research and Innovation, University of Pretoria Research Development Programme and the University Capacity Development Programme for the University of Pretoria. Acknowledgements The authors thank the participants in the previous phases that informed the development of the DCE.Peer reviewedPublisher PD

Mode and Frame Matter : assessing the impact of survey mode and sample frame in choice experiments

This work was funded by the Medical Research Council MR/J004812/1. The Health Economics Research Unit is funded by the Chief Scientists Office of the Scottish Government Health and Social Care Directorates.Peer reviewedPublisher PD

The development of a measure of social care outcome for older people. Funded/commissioned by: Department of Health

An essential element of identifying Best Value and monitoring cost-effective care is to be able to identify the outcomes of care. In the field of health services, use of utility-based health related quality of life measures has become widespread, indeed even required. If, in the new era of partnerships, social care outcomes are to be valued and included we need to develop measures that reflect utility or welfare gain from social care interventions. This paper reports on a study, commissioned as part of the Department of Health’s Outcomes of Social Care for Adults Initiative, that developed an instrument and associated utility indexes that provide a tool for evaluating social care interventions in both a research and service setting. Discrete choice conjoint analysis used to derive utility weights provided us with new insights into the relative importance of the core domains of social care to older people. Whilst discrete choice conjoint analysis is being increasingly used in health economics, this is the first study that has attempted to use it to derive a measure of outcome