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Unit for Social and Community Psychiatry

Retention of participants in trials


Understanding what affects participation in mental health trials is essential for ensuring ethical and effective conduct, successful completion of data collection, but also to engage a wide range of the population in clinical research. 

The main objective of this doctoral research study is to identify factors affecting retention of participants with psychosis in trials evaluating non-pharmacological interventions.

The research will involve: reviewing the existing evidence; interviewing patients and researchers; and analysing individual patient data from completed studies.

The study is funded by the Life Sciences Initiative at Queen Mary University of London. The project is based within the Unit for Social and Community Psychiatry and works closely with the School of Geography.

Research questions

  • Why do people with psychosis participate in or drop out of trials evaluating non-pharmacological interventions?
  • What factors influence the decision-making about trial participation?
  • What are the characteristics of people who participate in and who drop out of trials?
  • What are the procedures and retention strategies used in trials involving people with psychosis?
  • How can existing retention strategies be made more effective for patients with psychosis?

Research activities

  • A systematic literature review will look at the reported participation rates of people with psychosis in large-scale studies evaluating non-pharmacological interventions.
  • Interviews with trial staff will find out about the trial procedures, retention strategies, views about selection bias and reasons for drop out, and best practice in retaining participants.
  • Interviews with patients with psychosis who have previously participated in a clinical trial will find out about the decision-making process, the barriers and facilitators to participation, and any other factors that affected their decision to continue/discontinue participation.
  • A meta-analysis of individual patient data will seek to identify predictors of retention and drop out from trials, such as age, gender, ethnicity, education, place of residence.


  • By exploring what influences people with mental health problems to participate in medical research, this project will contribute to the development of ethical and inclusive clinical trial retention practices, as well to wider public debates and academic scholarship concerned with the ethics and practice of medical research.   


Paulina Szymczynska


Life Sciences Institute, Queen Mary University of London

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