Quantifying Preferences for Urea Cycle Disorder Treatments Using a Discrete Choice Experiment

Abstract

Abstract Background Urea cycle disorders (UCDs) are rare, inherited metabolic disorders that can lead to central nervous system toxicity due to ammonia accumulation. Nitrogen-binding medications can be efficacious in the treatment of UCDs but may be associated with attributes that negatively impact adherence. This study sought to quantify the attributes of these medications influencing overall prescription and patient adherence. Results A web-based, quantitative survey including discrete choice experiment (DCE) methodology captured responses from health care providers for patients with UCDs. In the DCE, respondents were presented with a series of hypothetical treatment profile sets that described treatment attributes such as route of administration, taste/odor, preparation instructions, packaging, dose measurement, and weight use restrictions. From 16 choice sets, with 3 hypothetical product profiles, respondents evaluated the product attributes most preferred for overall treatment selection or for patient adherence. A total of 51 respondents completed the survey. Respondents reported dissatisfaction with current treatments [mean rating (SD) = 5.4 (1.7); Likert scale with 1 = not at all satisfied through 9 = extremely satisfied]. Using DCE methodology, four attributes achieved relative importance (RI) scores > 16.67% [i.e., 100/6 (number of attributes), the value if all attributes were considered of equal importance] indicating higher overall preference: taste/odor (24%), weight restrictions (21%), preparation instructions (18%), and route of administration (17%). When considering adherence, three attributes achieved RI scores > 16.67%: taste/odor (28%), preparation instructions (21%), and route of administration (17%). Within the taste/odor attribute, preference weights for “taste/odor masked” were higher than “not taste/odor masked” for overall preference for prescribing [mean (SD); 1.52 (1.10) vs -1.52 (1.10)] and preference for treatment adherence [mean (SD); 73.8 (55.2) vs -73.8 (55.2)]. Conclusions Taste/odor was the most important attribute influencing overall preference for both prescribing and for patient adherence and compliance, with taste/odor masking preferred. Optimizing nitrogen-binding medications to encourage increased patient adherence through masking taste/odor may support improved outcomes in UCDs.