Discrete Choice Experiments in HERU

Discrete Choice Experiments are applied throughout the HERU research themes. These are some of the current and recently completed projects from different themes which apply discrete choice experiments.

Current Projects

Economic modelling: reducing health harms of foods high in fat, sugar or salt

Having a poor diet and being overweight can have a negative impact on health and wellbeing. To address this public health concern, the Scottish Government published its Diet and Healthy Weight Delivery Plan in July 2018. This included a number of actions focusing on children, the food environment, weight management services and leadership to promote healthy weight and diet. The primary aim of plan is to reduce the public health harm associated with the excessive consumption of calories, fat, sugar and salt, including the risks of developing type 2 diabetes, various types of cancer and other conditions such as cardiovascular disease. One commitment was to consult on plans to restrict the promotion and marketing of targeted foods high in fat, sugar or salt.

This research will use existing data from Kantar World Panel and collect new primary data on consumer preferences, using Discrete Choice Experiments, inform future Scottish Government policy on the impact of restricting the promotion and marketing of discretionary foods high in fat, sugar and salt.

HERU researchers involved in this research project: Paul McNamee and Patrícia Norwood

External Collaborators: C. Revoredo (Scotland Rural College)

Enhancing recruitment and retention of rural doctors in Scotland: a mixed-methods study

Communities living within remote and rural areas of Scotland face difficulties in accessing quality healthcare. One of the largest challenges in providing healthcare to such communities is the ability to recruit and retain healthcare staff. While there is some evidence that people born or brought up in remote and rural areas are more likely to want to work there, there is little evidence about how to attract in and keep people from more diverse backgrounds.

This Chief Scientist Office funded project, will use qualitative interviews to better understand the experiences and motivation of doctors with respect to remote and rural medical positions within Scotland. The findings from this qualitative phase, led by our sister Unit HSRU, will then inform the development within HERU of a discrete choice experiment to value the factors which influence career decision making in relation to remote and rural working.

HERU researchers involved in this research project: Diane Skåtun and Verity Watson

External collaborators: L. Locock, Z. Skea (Health Services Research Unit (HSRU); J. Cleland (Nanyang Technological University, Singapore); P. Wilson (Rural Health, Institute of Applied Health Sciences, University of Aberdeen); P. Murchie, R. Hollick (Institute of Applied Health Sciences, University of Aberdeen).

REFLeCt trial - Fluoride toothpaste to prevent dental caries

REFLECt trial: A Randomised controlled trial to Evaluate the clinical and cost effectiveness of prescribing high concentration FLuoride toothpaste in preventing and treating dEntal Caries in high-risk older adulTs

The RELFECT study is a two arm, parallel group pragmatic open label randomised controlled trial with 36 month follow.  The trial will randomise participants from Manchester, Scotland and Northern Ireland.  The primary clinical outcome for the study is restoration or extraction due to caries.  The health economic outcomes for the study are NHS and patient perspective costs, willingness to pay and net benefit.  Two economic analyses will be completed, the first, a within trial analysis over a three year time horizon.  Discrete choice experiments will be used to value the trial outcomes within a cost-benefit analysis framework to reflect broader measures of value to patients.  The findings will be compared with a standard cost-utility analysis.  A micro-simulation modelling study will be conducted to extrapolate the findings of the trial over a participant’s lifetime.   This study will provide important information on the value of prescribing a treatment which is increasing in use, without any evidence to support its effectiveness or cost-effectiveness.

HERU researchers involved in this research project: Dwayne Boyers

External collaborators:  Tickle, M., Walsh, T., Worthington, H., Glenny, A-M., Pretty, I., Birch, S. (University of Manchester); Clarkson, J. (University of Dundee).

What keeps doctors practising? An investigation into the factors that influence doctors' retirement decisions

This project will investigate what factors doctors consider when deciding when to retire, the relative importance of these factors and how doctors might trade-off between them.

Continuing HERU’s collaboration with the Centre for Healthcare Education Research and Development (CHERI), this research will identify the push-pull factors related to the intention to retire, and will employ a discrete choice experiment (DCE) to examine which of these factors are most valued by doctors nearing the end of their careers. The research will use qualitative face-to-face interviews along with a Scotland-wide survey; distribution of which will be facilitated by the British Medical Association and NHS Education for Scotland.  

HERU researchers involved in this research project: Diane Skåtun, Ourega-Zoé Ejebu, Terry Porteous and Mandy Ryan

External collaborators: Cleland, J, (CHERI)

Recently Completed Projects

Analysis of choice behaviour and potential mechanisms of change

This project reviewed the relevant economic literature to map out theoretical approaches and empirical examples for further analysis. Econometric analysis was then carried out using secondary data to investigate children’s diets and adult fruit and vegetable consumption. A discrete choice experiment (DCE) was undertaken to investigate the effect of introducing colour coding of calorie information within a traffic light food labelling system. The DCE incorporated eye-tracking technology in the pilot stage to help understand the effect of the additional information. A full-scale study was then conducted using an online panel.

Outcome and Translation

The secondary data analysis of children’s diets showed that household characteristics explain more of the variation than child characteristics, with adult healthy eating behaviour positively associated with children’s behaviour. The inclusion of both child and household effects reduces the amount of unexplained variation in children’s healthy eating although the unexplained variation remains substantial. The analysis of adult diet identified differences in determinants between fruit and vegetables and separate effects for income level and source of income.

In the food choice DCE, we found that saturated fat appears to be the attribute with largest impact on participants’ choices, followed by fat, with salt consistently ranked as least influential attribute. The willingness-to-pay (WTP) values are largely influenced by the number of sandwiches presented to the participants, with lower levels of WTP for a four sandwich choice. We also found that deciding to colour-code for calorific value has an important effect on the valuation of this attribute. Our results confirm that colour coding the nutritional information can significantly influence food choices.

HERU researchers involved in this research project: Anne LudbrookShelley FarrarLynda McKenzie, Damilola Olajide, Patrícia Norwood, Nicolas Krucien and Mandy Ryan

External collaborators: P Morgan (Rowett Institute of Health and Nutrition (RIHN))

INTERVAL - Investigation of NICE Technologies for Enabling Risk-Variable-Adjusted-Length dental recalls trial

A parallel-group, randomised, controlled comparison of three forms of dental recall strategy (6-month recall, risk-based recall and 24-month recall) evaluated the effectiveness and cost-effectiveness of these dental recall strategies by assessing their impact on maintaining oral health. A cost–benefit analysis was undertaken to assess the efficiency of the alternative recall strategies. Willingness to pay was elicited using a discrete choice experiment.

Outcome and Translation

Publications are currently in development.

HERU researchers involved in this research project: Marjon van der Pol and Dwayne Boyers

External collaborators: N Pitts, J Clarkson, D Bonetti, R Freeman, D Ricketts (University of Dundee); C Ramsay, (HSRU, University of Aberdeen); H Worthington (University of Manchester); T Anderson, W McCombes, L Young (NHS Education for Scotland); F Burke, D White (University of Birmingham); G Douglas (University of Leeds); R Gorter (University of Amsterdam); R Herbert (University of Cardiff); P Hodge (University of Glasgow); G Humphris (University of St. Andrews); T Mettes (Radboud University, NIJMEJEN Medical Centre, The Netherlands); I Needleman (UCL Eastman Dental Institute) and M Ross (University of Edinburgh)

Understanding push-pull factors in medical careers decision making

Existing research indicates factors such as the perceived benefits of particular specialities, wish for quality of life, and demographic factors, such as gender, are influential. However, we do not know the most important ‘push-pull’ careers-decision making factors for the current generation of UK medical students and trainees. What drives medical students and trainees away from a place or a speciality? What draws them to a new location or a different speciality? To what extent are specific factors important at different transitions?

This project used anonymous, online surveys to gather contemporary UK data on these issues from medical trainees and students. A Discrete Choice Experiment was used to identify the most important push-pull factors in medical careers-decision making.

Outcome and Translation

Our results suggest organisations could focus on improving working conditions for trainees to a minimum standard, promote linked training positions for medical couples, and provide access to career support for non-medical partners. Alternatively, organisations might provide monetary incentives to trainees for accepting posts that do not meet their preferred conditions. Medical students were also found to value good working conditions more than they value geographical location. 

HERU researchers involved in this research project: Diane Skåtun, Verity Watson and Nicolas Krucien

External collaborators: J Cleland (University of Aberdeen), C Rees (University of Dundee), K Mattick (University of Exeter) and P Johnston (NHS Education for Scotland (NES))

Using discrete choice experiments to investigate optimal skill mix

With increasing demands on health services policy is looking at alternative ways of providing healthcare. Examples include extending the role of pharmacists and nurses in the management of common ailments, promoting self-care of symptoms indicative of self-limiting illness, and extending the roles of specialist nurses and physician associates in some clinical areas. We use discrete choice experiments (DCEs) to investigate preferences in the management of different illnesses.  

Outcome and Translation

A general finding is that, whilst individuals often prefer to see a doctor or consultant, improvements in other aspects of care (reduced waiting time, continuity of care, longer consultation times) can compensate them for not seeing their preferred health worker. 

HERU researchers involved in this research project: Mandy RyanVerity Watson and Patrícia Norwood.

External collaborators: Terry Porteous, Christine Bond, Alison Elliott, Phil Hannaford and Peter Murchie (Academic Primary Care, University of Aberdeen)