Discrete Choice Experiment Versus Best-Worst Scaling: An Empirical Comparison in Eliciting Young People's Preferences...

Discrete choice experiments (DCEs) and best-worst scaling (BWS) profile cases (BWS case 2, or BWS-2) have been increasingly used in eliciting preferences towards health care interventions. However, it remains unclear which method is more suitable for preference elicitation, particularly in the mental health context. This study aims to compare: (1) the preference results elicited from a DCE and BWS-2; and (2) the acceptability of the two methods in the context of web-based mental health interventions (W-MHIs) for managing anxiety and depression in young people.

Participants were aged 18-25 years, lived in Australia, and self-reported experiencing anxiety and/or depression in the past 12 months. They also had either an intention to use W-MHIs or previous experience with W-MHIs for managing anxiety and/or depression. Recruitment was conducted online via social media and Deakin University notice boards. Eligible participants completed an online survey containing eight DCE and eight BWS-2 choice tasks. Both types of choice tasks comprised six attributes. A multinominal logit model was used to estimate the preference weights and relative importance of attributes. Acceptability was assessed on the basis of dropout rate, completion time, task difficulty, understanding, and participants' preferred type of choice task.

A total of 198 participants (mean age: 21.42 ± 2.3 years, 64.65% female) completed the survey. Both DCE and BWS-2 predicted that cost was the most important attribute in young people's decision to engage with W-MHIs. However, the two methods differed in the relative importance of attributes and the preference ranking of levels within attributes. The DCE was perceived as easier to understand and answer, with nearly 64% of the participants preferring it over the BWS-2.

While both methods found cost was the most important attribute associated with engagement with W-MHIs, differences in the ranking of other attributes suggest that DCE and BWS-2 are not necessarily interchangeable. Increased acceptability by study participants of the DCE format suggests that this technique may have more merit than BWS-2-at least in the current study's context. Further research is required to identify the optimal method for determining the relative importance of attributes.