A Protocol for Developing a Discrete Choice Experiment to Elicit Preferences of General Practitioners for the Choice of Specialty

Objectives: Discrete choice experiment (DCE) has been increasingly used in studies investigating preferences of the health workforce. This pilot study aimed to provide a comprehensive protocol for design and quality assessment of a DCE to elicit preferences of general practitioners for the choice of specialty. Methods: We conducted 3 rigorous qualitative studies, including a review of literature, qualitative interviews, and focus group discussion to develop attributes and levels of the DCE. Then a D-efficient fractional factorial design was applied to generate choice tasks and to block them into 4 equal versions using SAS software. Two hundred and forty general practitioners participated in a pilot study conducted to evaluate the quality of the instrument using 7 tests. Results: The qualitative studies resulted in the development of 8 attributes and 24 levels. Experimental design led to the generation of 36 choice tasks divided into 4 blocks. The pilot study revealed that the instrument has validity and reliability and also indicated that the design is comprehensible and feasible. Conclusions: This study provided an integrated, comprehensive framework for development and quality assessment of a DCE that could be used in other studies. The pilot study indicated that the instrument is of sufficient quality because it was developed using rigorous qualitative studies and accurate experimental design method.