Qualitative in-trial interviews: a targeted literature review exploring objectives and methods

Background Qualitative in-trial interviews are valuable in the drug development process to understand what is important to patients. In-trial interviews can be used to collect patient experience data and provide additional perspectives on trial participation, the effects of treatment, and/or clinical outcome assessments (COAs). The aim of this review was to increase our understanding of in-trial interview studies in terms of their objectives, data produced, methodology used to obtain these data, and how these data were used to inform decision-making. Methods A targeted review of the PubMed database was performed in November 2024 to identify publications reporting results from in-trial qualitative interview studies associated with Phase I, II, or III clinical trials. In addition, selected regulatory documents related to the treatments used in the interview studies were reviewed to examine how in-trial interviews were used to inform regulatory decision-making. Results Forty-six publications reporting 43 in-trial interview studies were identified. Interviews involved patients (29 studies; 67%), caregivers (6 studies; 14%), or a combination of both (8 studies; 19%), and the interview samples ranged in size from two to 111 (median, 27; IQR, 15–45). The most common interview study objectives were understanding participants’ experiences of their condition during the clinical trial (including effects of study treatment) or prior to the clinical trial (33 studies [77%] and 19 studies [44%], respectively). Interview study findings were frequently reported as complementing efficacy, safety, and/or tolerability findings from the clinical trial ( n = 28; 65%), providing support for COAs used in the trial ( n = 15; 35%), and being useful in guiding future research and clinical studies ( n = 14; 33%). Findings from five (12%) of the interview studies were included in regulatory documents relating to the treatment used in their associated main trials. Conclusions The use of in-trial interviews has grown over the last 20 years, and particularly in the past five years (2020–2024). The wide variability in sample size, purpose, and use of interview results reflects the versatility of these studies in addressing diverse research objectives. In-trial interview findings have proved valuable in regulatory and HTA decision-making, and for informing decision-making in drug development. Although health authorities have shown increasing interest in data from in-trial interviews in recent years, clearer guidance on the use and value of in-trial interviews in regulatory decision-making could help to promote their wider use in clinical research. Clinical trial number Not applicable.