Potential PhD Projects Available in ScHARR

In the first instance, students interested in one of the projects below should contact the relevant potential supervisor. Please note there is no funding attached to any of these projects, any potential student interested would need to source their own funding. 

Environmental influences on health behaviour

Supervisor: Emma Hock (emma.hock@sheffield.ac.uk)

The impact of the environment on health behaviour is beginning to be recognised, but there is much that is unknown. Changes to the environment (also known as ‘nudging’) have the potential to impacton people’s behaviour and also social and psychological factors and contexts.

In particular I am interested in supervising a PhD examining the impact of building design features on people’s physical activity behaviour (and possibly on how people think and feel, and on the broader culture), although I am open to suggestions for supervising doctoral research concerning other aspects of environmental structures on other health behaviours. Within the doctoral research programme, I would envisage:

  • Observational research examining the impact of building design on physical activity in terms of movement throughout the building – largely quantitative but with scope for qualitative research to assess how people see the physical structure impacting on their activity and habits
  • Intervention/s to assess the impact of altering elements of building design to encourage physically active movement throughout the building – mixed methods, either in terms of quantitative intervention design and measurement with qualitative process evaluation, or designing intervention/s through participatory action research or social action and using quantitative and qualitative techniques to assess the impact of the intervention

Physical activity as a smoking cessation aid

Supervisor: Emma Hock (emma.hock@sheffield.ac.uk)

There is much experimental research to suggest that short bouts of physical activity (such as a 10-minute brisk walk) can reduce cigarette cravings in abstaining smokers, however to date research examining the impact of integrating physical activity into smoking cessation programmes has only examined formal structured exercise rather than encouraging its use in short bursts to relieve cravings. Smoking cessation advisors within the UK Stop Smoking Service also feel that physical activity can be most beneficial if it is promoted as a cessation aid and pilot collaborative research within the UK Stop Smoking Services suggests that this is feasible, however the effectiveness of such an intervention has yet to be fully examined.

I would be interested in supervising doctoral research examining the effectiveness of the use of short bouts of physical activity as a smoking cessation aid within the Stop Smoking Services. I would
envisage the doctoral research programme consisting of a large trial or series of small trials with a qualitative process evaluation and potentially making use of collaborative action research.

Sample size estimation for stepped wedge cluster randomised controlled trial designs

Supervisor: Professor Stephen J Walters ( s.j.walters@sheffield.ac.uk )

The stepped wedge cluster randomised controlled (SWcRCT) trial is a relatively new study design that is increasing in popularity and is used in the evaluation of health service delivery type interventions. It is an alternative to the more standard or traditional parallel cluster randomised controlled trial (cRCT) designs, which are commonly used for the evaluation of service delivery or policy interventions delivered at the level of the cluster. The design includes an initial period or step in which no clusters are exposed to the intervention. Subsequently, at regular intervals (the “steps”) one cluster (or a group of clusters) is randomised to cross from the control to the intervention under evaluation. This process continues until all clusters have crossed over to be exposed to the intervention. At the end of the study there will be a period when all clusters are exposed. Outcome data collection continues throughout the study, so that each cluster contributes observations under both control and intervention observation periods.

The proposed research plan would be to undertake a review of the statistical literature on methods for estimating sample size for stepped wedge cluster randomised controlled trials; and the statistical methods for analysing the outcome data from such designs. The project would then involve computer simulation and analysis to compare the different methods of sample size estimation and analysis with the view to developing guidance on how to estimate the sample size required for stepped wedge cluster randomised controlled trial designs.


Hemming K, Haines TP, Chilton PJ, Girling AJ, Lilford RJ. The stepped wedge cluster randomised trial: rationale, design, analysis, and reporting. BMJ2015;350:h391

Propensity Score estimation and matching for multiple treatment comparisons in observational studies

Supervisor: Professor Stephen J Walters ( s.j.walters@sheffield.ac.uk )

The use of propensity scores (PS) to control for pre-treatment imbalances on observed variables in non-randomized or observational studies examining the causal effects of treatments or interventions has become widespread over the past decade. Until recently, the PS method has been applied exclusively for 2 treatment comparison settings (e.g. treatment vs. control) despite that it is frequently of interest to compare more than 2 treatments or interventions in health research. PS covariate adjustment, inverse probability weighting (IPW) estimator, and PS matching are the three PS approaches commonly seen in two treatment comparisons.

The proposed research plan would be to undertake a review of the statistical literature on methods for estimating propensity scores for multiple treatment comparisons in observational studies; and the methods for matching these PS with multiple treatment comparisons; followed by an audit of recently published multiple treatment comparison observational studies which used propensity scores to determine what PS estimation and matching methods are commonly used. The PS estimation methods and PS matching and their effect on statistical analysis and conclusions will be compared using data from several observational studies with multiple treatment comparisons. The project would then involve some computer simulation and analysis to compare the different methods of PS estimation and matching with the view to developing guidance on how to estimate Propensity Scores for multiple treatment comparisons and how to use or matching on the propensity score in the analysis of the outcomes in multiple treatment comparisons in observational studies.


Rosenbaum, Paul R.; Rubin, Donald B. (1983). "The Central Role of the Propensity Score in Observational Studies for Causal Effects". Biometrika 70 (1): 41–55. doi:10.1093/biomet/70.1.41.

Generic Dimensions of Barriers and Facilitators to the Uptake and Acceptability of Complex Interventions

Supervisor: Andrew Booth ( a.booth@sheffield.ac.uk )


“Successful implementation depends on changing behaviour – often of a wide range of people. This requires a scientific understanding of the behaviours that need to change, the factors maintaining current behaviour and barriers and facilitators to change” (MRC Framework). Carl May has distilled barriers to and facilitators of supply-side implementation to four domains described by the NPM: interactional workability of collaborative care; relational integration; skill-set workability; contextual integration.

Three concepts, barriers, facilitators and acceptability, are ubiquitous in qualitative research evaluating the uptake of therapeutic interventions by participants however action researchers generally have to establish sub-domains for each project on an ad hoc basis . While each health care intervention and context does present unique challenges, if there were a level of abstraction at which sub-domains could be defined, it would expedite the categorisation of qualitative material by action researchers In fact, several systems already exist, mostly outside of the health services / technology research sphere (see over). Between some there appear to be overlap and sometimes commensurability of terms but there is no obvious standard system of exhaustive and mutually exclusive groups.


Develop a system of mutually exclusive (?), exhaustive categories of factors which relate to the uptake of complex interventions by patient groups.



Year 2. CONSULTATION AND REANALYSIS OF CASE STUDIES. Convene sample of qualitative researchers who have produced case studies on the barriers / facilitators / acceptability of complex interventions. Delphi exercise on commensurability of terms. Researcher takes primary datasets away recodes case studies using new system. Preparation of “dummy statements” survey for factor analysis?

Year 3. CONSULTATION, FACTOR ANALYSIS AND WRITE-UP. Participating researchers answer “dummy statements” survey. New Delphi exercise on the success of the re-coding study. Write-up of results.

Healthcare Communication Systems

Supervisor: Susan Baxter (s.k.baxter@sheffield.ac.uk )

The way that healthcare staff share information about patients is a key element which impacts on the quality and safety of patient care. There have been a number of interventions developed in recent years such as checklists to use in operating theatres or to use when making or receiving telephone calls. There has also been a focus in the UK on improving staff team working skills, with communication being an important part of these interventions. Recent high profile failures in care however indicate that there is much work still to be done to ensure optimal communication systems between hospital professionals, between hospitals and the community, and between health and social care.

There are potentially many strands of this issue that could be investigated in a PhD study including staff/patient perceptions of interventions, evaluating systems, and exploring the impact on patient outcomes. The challenge of successful transfer of information within healthcare delivery has applicability internationally. A proposal could include a systematic review of effectiveness of interventions, a review of qualitative evidence or use one of the emerging methods for synthesising evidence such as realist synthesis or logic modelling. Besides evidence synthesis methods primary research could use qualitative approaches or mixed method designs.


Baxter, S., & Brumfitt, S. (2008). Once a week is not enough: evaluating current measures of teamworking in stroke. Journal of Evaluation in Clinical Practice, Volume 14, Issue 2, pp 241-247

Baxter, S., & Brumfitt, S. (2008). Benefits and losses: a qualitative study exploring healthcare staff perceptions of teamworking. Quality and Safety in Healthcare, Volume 17, Issue 2, May. 127-130

Baxter, S., & Brumfitt, S. (2008). Professional differences in interprofessional working. Journal of Interprofessional Care, Volume 22, Issue 3, pp 239-251

Baxter, S., Killoran, A., Kelly, M., Goyder, E. (2010). Synthesizing diverse evidence: the use of primary qualitative data analysis methods and logic models in public health reviews. Public Health, Volume 124, Issue 2, pp 99-106

Further potential PhD Topics in HEDS can be found here.