Assessing preferences for schizophrenia outcomes: comprehension and decision strategies in three assessment methods

Quantifying the importance of treatment outcomes by measuring preferences allows construction of aggregate outcome indicators that reflect the relative importance of multiple outcomes, trade-offs between outcomes, and the perspectives of different stakeholders. However, standard preference assessment methods are cognitively complex and may be particularly challenging for persons with schizophrenia and other serious mental illnesses. Preferences may not be meaningful or comparable across stakeholder groups if the groups do not use the methods in similar ways. This study combined qualiative and quantitative methods to compare comprehension and decision strategies across three standard preference assessment methods (Rating Scale, Time Tradeoff, and Paired Comparison) in 2 stakeholder groups (consumers of schizophrenia treatment and clinicians). Results indicate that the Rating Scale method is likely to yield the most valid and comparable preference values because it is well understood and acceptable to both consumers and clinicians. Both groups found the Time Tradeoff method difficult to use and poorly suited to evaluating schizophrenia outcomes.