Possible PhD topics

This page lists just a few potential areas of research that prospective students might study in HEDS.  The list is not exhaustive and we encourage interested prospective students to also visit our individual staff pages to find potential supervisors with relevant research interests.

Specific PhD Topics

Methods for adjusting for treatment switching in clinical trials

Nick Latimer

Treatment switching, in which patients randomised to the control group of a clinical trial are permitted to switch to the experimental treatment group, is common in trials of oncology treatments for both ethical and practical reasons. When patients in the control group switch to, and benefit from, the experimental treatment, a standard intention-to-treat (ITT) analysis (a comparison of groups as randomised) will underestimate the ‘‘true’’ survival benefit associated with the new treatment, that is, the benefit that would have been observed if switching had not been permitted. Such an analysis would not meet the requirements of the economic evaluation decision problem that is essential for health technology assessment (HTA), whereby a state of the world in which the new therapy is used for treatment is compared to one in which it is not. Statistical methods have been developed specifically to take into account treatment switching, but these make important limiting assumptions and there is some concern over their use in HTA. More research into adjustment methods is required.


Aki Tsuchiya

Health care resources are limited and therefore need to be allocated efficiently, but they also need to be allocated in a fair, equitable manner. One topic where the possible conflict between efficiency and equity occurs is that of severity and disability. Should we, or should we not, give higher priority to improving the health of people who suffer from chronic and severe health problems, even when their treatment is not as cost effective as other treatments? And if yes, for what reason, and by how much? This is an area where the views held by the general public may differ markedly from the views held by those who are actually living with the health problems in question. This leads to two further research questions. First, if people with such health problems adapt to their condition, does this mean they no longer need to be given higher priority, compared to those who (for whatever reason) do not adapt, and why? Second, if general public and patients have different views, then there is an issue of procedural justice: whose views should public policy be based on, and why?

The relationship between discrete choice experiments and QALYs

Donna Rowen

Applications are invited from capable and enthusiastic prospective PhD students to investigate the methodological underpinnings of discrete choice experiments (DCEs) and/or ordinal valuation methods in health care, the methodological underpinnings of quality-adjusted life-years (QALYs), and the extent to which DCEs and/or ordinal valuation methods may be used as a vehicle for estimating utility weights for QALY calculations. Utility weights generated for specific health states relating to several conditions will be generated using a DCE format and then compared to those generated using more standard scaling techniques e.g. standard gamble and time trade-off. The research will discuss the relative advantages and disadvantages of each technique and assess their performance in terms of 1) the validity of the weights generated and 2) their applicability for use in the estimation of QALYs.

Methods for Assessing the Presence and Likely Effect of Dissemination Bias within Systematic Reviews of Qualitative Research

Andrew Booth

In comparison with quantitative systematic reviews, methods for identifying and exploring the effect of dissemination bias (including publication bias) are under-developed and require systematic investigation. A recent multi-national survey of editors, authors and researchers has identified a considerable prevalence of non-dissemination. A related mapping study, conducted by ScHARR with international collaborators, has revealed little empirical work on the extent and nature of dissemination bias in qualitative research. The international CERQual team has identified numerous research priorities for exploration, some of which may underpin the final version of this prospective PhD. For example the existence of “truncation bias”, where authors omit valuable qualitative data because of restrictions in journal word counts could be investigated through a matched cohort of qualitative journal articles and corresponding qualitative PhD publications. Similarly restrictions on word counts for the Methods sections of qualitative research studies may result in them being inadequately evaluated and assessed during the peer review process. The research will undertake genuinely ground-breaking methodological work in exploring and developing methods for detecting dissemination bias and, more importantly, taking into into account in decision-making when using systematic reviews of qualitative research.

Methods for Exploring Time Lags between Unhealthy Behaviours and Subsequent Harm

Andrew Booth

Changes in many unhealthy behaviours are temporally linked to subsequent changes in rates of harm. Initiation of an unhealthy behaviour, for example, initiation of smoking or increased alcohol consumption are not typically accompanied by immediate health consequences. Instead the consequences may come after a prolonged and often delayed interval. Methodological approaches for analysing this relationship have been suggested, however, the problem of time lags is not well-addressed. This study will review time lag specifications across a selection of unhealthy behaviours, following our previous published work on alcohol consumption, to look at (a) time to first effect on harm, (b) time to full effect and (c) the functional form of the effect accumulation from first to full effect to inform modelling of the relationship between changes in a selection of unhealthy behaviours and subsequent changes in rates of harm. Related investigation may focus on related issues such as modelling the effects of cessation of the unhealthy behaviour when the long-term consequences of previous exposure appear many years after cessation.

Qualitative Evidence Synthesis (QES) in HTA (Health Technology Assessment) and Guideline development

Chris Carroll

There are currently no standards or methods endorsed by international HTA agencies for conducting or incorporating QES in HTAs, even though patient-centred care is increasingly being recognised as a vital element of health service provision. The aim of the proposed research is to explore methods of QES as an adjunct to clinical and cost-effectiveness research in the health technology assessment process, and to assess how this might inform the decision-making process.

The Health Technology Assessment Process

Chris Carroll

The HTA process in England and Wales, as undertaken by the National Institute of Health and Care Excellence (NICE) to make recommendations to the Department of Health, is incredibly varied and applies a diversity of criteria, moethds and processes.  The proposed research would use a combination of documentary analysis and primary qualitative research techniques to explore one or more elements of the decision-making process.  The basic principles of this proposal would also apply to the HTA process and its role in decision-making in other countries.

Reviewing Evidence for Cost Effectiveness Model Parameters

Eva Kaltenthaler

Although the methods for reviewing the effectiveness evidence in health technology assessments are well developed, there is little guidance available regarding the best approaches to reviewing the evidence for other parameter values within decision analytic models. There is a need for such information to inform health technology assessment methods. The proposed research would formalise, pilot and evaluate appropriate review methods needed to identify different types of parameter values.