KEY TAKEAWAYS
- The LIBRETTO-531 phase 3 trial aimed to investigate patients’ perceptions of bother, burden, and tolerability and assess the clarity of FACT-GP5.
- The findings endorsed FACT-GP5’s content validity for assessing treatment tolerability and defining “high side-effect bother” in LIBRETTO-531.
Danielle Altman and the team aimed to investigate patients’ perceptions of bother, burden, and tolerability and evaluate the clarity of the FACT-GP5 questionnaire.
The study conducted semi-structured virtual qualitative interviews with participants enrolled in the LIBRETTO-531 trial who had completed the FACT-GP5 at baseline. Participants provided consent before the interviews. The FACT-GP5, a single-item measure, evaluated the overall impact of treatment side effects using a 5-point Likert scale (0=not at all to 4=very much) with a 7-day recall period.
The interviews comprised two main components, including concept elicitation regarding participants’ perceptions of bother, burden, and tolerability of treatment side-effects, and cognitive debriefing of the FACT-GP5 and its associated response options indicating “high side-effect bother.” Interview transcripts underwent thematic analysis using ATLAS inductive and deductive coding techniques.ti software. Saturation analysis was performed to assess the acquisition of new information in each set of 5 interviews.
About 34 participants were interviewed, with a median age of 61 years (range=23–76), and 67.6% were male. The median time between the first day of study treatment and the interview date was 50 weeks (range=11–135). Conceptual saturation regarding bother, burden, and tolerability was achieved by the 4th group interviewed.
Participants described side effects as bothersome if they caused physical discomfort/annoyance, interfered with daily activities, or induced emotional distress. “Burden” suggested more severe side effects or greater interference with daily activities than “bother.” Most participants associated bother and burden with their perceived tolerability of a treatment. Cognitive debriefing revealed that FACT-GP5 was clear, understandable, and relevant. A majority of participants (68%) indicated that options “3” or “4” were linked to discontinuing treatment and high side-effect bother.
The results endorse the content validity of FACT-GP5 for evaluating treatment tolerability and defining “high side-effect bother” in LIBRETTO-531.
The trial was sponsored by Loxo Oncology, Inc.
Source: https://www.ispor.org/heor-resources/presentations-database/presentation/intl2024-3898/135996
Clinical Trial: https://clinicaltrials.gov/study/NCT04211337
Altman D, Choi J, Elisei R, et al. (2024). “Content Validity of FACT-GP5 to Assess Treatment Tolerability in Participants With Progressive, Advanced, Kinase Inhibitor-Naïve, RET-Mutant Medullary Thyroid Cancer: Qualitative Interview Sub-Study of the LIBRETTO-531 Trial.” Presented at ONS 2024, 2024-05, ISPOR 2024, Atlanta, GA, USA Value in Health, Volume 27, Issue 6, S1 (PCR200)
