OBJECTIVES: Valuation studies, used to inform national healthcare policies, represent public views on which aspects of health matter the most, yet sample representativeness may be affected by interview mode. Video interviews may preclude the digitally excluded; in-person interviews may exclude people unwilling to travel or welcome an interviewer into their home. This study assesses the impact of mode on sample composition, and examines the equivalence, feasibility and acceptability of video and in-person interviews for generating time trade-off (TTO) values for EQ-5D-5L, to determine whether both could be used in a single study and data combined.

METHODS: Sample participants in England were recruited using a blended approach of different methods and sampled based on age, gender, ethnicity, and index of multiple deprivation. Participants were randomly allocated to video or in-person interview and completed TTO tasks for the same 10 EQ-5D-5L health states using EQ-VTv2 software. Data was assessed across mode using: participant preferred mode of interview; sample representativeness; participant understanding and feedback; data quality; mean TTO and TTO distribution for each health state; and regression analyses assessing the impact of mode on TTO values whilst controlling for participant characteristics.

RESULTS: There was no clear preference for mode across all participants (n=360), but characteristics of people preferring video or in-person interviews significantly differed. TTO values differed across modes for more severe states, but mode does not appear to be the cause when controlling for other factors. Video interviews generated marginally lower quality data across some criteria.

CONCLUSIONS: Neither video nor in-person TTO interviews had clearly superior performance, and TTO responses did not vary significantly overall. However, characteristics of people preferring each mode differed significantly. It is recommended that both in-person and video interviews are used in TTO valuation studies, to enable accessibility and inclusivity of those able to participate, maximising sample representativeness.