Contracted family doctor service is the main way of community prevention and treatment of hypertension and type 2 diabetes. With the continuous development of the concept and practice of "patient-centered" medical and health services, accurate allocation of service attributes and levels based on patient preferences has become a key path to improve service accessibility, compliance and health outcomes.

This study takes the research on the preference choices of patients with comorbidity of hypertension and type 2 diabetes mellitus (HTN-T2DM) for family doctor contract services as an example, detailing the entire process of attribute and level development, providing a reference and guidance for the development of attributes and levels in discrete choice experiments (DCE), and offering a reference for formulating strategies for family doctor contract services for patients with HTN-T2DM.

Under the guidance of the consolidated framework for implementation research (CFIR), a literature review and policy analysis were conducted to extract and collate potential attributes and construct an attribute pool, semi-structured interviews were carried out with 5 family doctors, 3 institutional principals, and 20 patients with HTN-T2DM from primary-health-care institution in Haikou city to specify the attributes and levels. Finally, 50 HTN-T2DM patients were recruited by convenience sampling to participate in a pretest to verify the rationality of the attributes and levels.

Through a literature review, 23 literatures were combed, among which 15 were in Chinese and 8 in English, and 18 attributes were collated. In combination with semi-structured interviews, 8 attributes and corresponding levels were determined. Through the pre-experiment, 7 attributes and levels were ultimately determined, namely, the nature of the institution (government-run/social-run/individual-run), service content (health consultation and guidance/traditional Chinese medicine for preventive treatment of diseases/personalized examination items), service mode (institutional visit/remote diagnosis and treatment/home visit service), self-payment cost (50/100/200 yuan per month), doctor's professional title (junior/intermediate/senior), implementation environment (with priority referral/without priority referral), and medication guidance (2 weeks/1 month/2 months).

Scientifically determining attributes and their levels is a crucial foundation for ensuring the effectiveness of DCE. Under the guidance of the CFIR, this study develops 7 attributes and corresponding levels for the preference of family doctor contract services for patients with HTN-T2DM, providing a reference for advancing research on the preference of family doctor contract services for HTN-T2DM patients. Empirical research can be carried out based on these findings in the future to promote the improvement of family doctor contract service strategies.