Patient and public involvement in numerical aspects of trials: a mixed methods theory-informed survey of trialists' current practices, barriers and facilitators.

OBJECTIVE: We aimed to find out if trialists involve patients and the public in numerical aspects of trials, how and what are the barriers and facilitators to doing it. DESIGN: We developed a survey based on the Theoretical Domains Framework. We used a mixed methods approach to analyse the data and to identify important domains. SETTING: Online survey targeting UK-based trial units. PARTICIPANTS: Stakeholders working in UK-based clinical trials, 18 years old or over, understand English and agree to take part in the study. OUTCOME MEASURES: Trialists' behaviour of involving patients and the public in numerical aspects of trials and its determinants. RESULTS: We included 187 respondents. Majority were female (70%), trial managers (67%) and involved public and patient partners in numerical aspects of trials (60%). We found lack of knowledge, trialists' perception of public and patient partners' skills, capabilities and motivations, scarce resources, lack of reinforcement, and lack of guidance were barriers to involving public and patient partners in numerical aspects of trials. Positive beliefs about consequences were an incentive to doing it. CONCLUSIONS: More training, guidance and funding can help trialists involve patient and public partners in numerical aspects, although they were uncertain about public and patient partners' motivation to be involved. Future research should focus on identifying public and patient partners' motivations and develop strategies to improve the communication of numerical aspects.