Title
Basel Assessment of Adherence to Immunosuppressive Medications Scale^©

Project Management
Sabina De Geest

INS-Team
Sabina De Geest
Kris Denhaerynck 

External Partner
Charles University, CZ (Barbora Vankova)
Universität Wien, AT (Frederik Haupenthal/Gregor Bond)
BAASIS^© consortium (researchers who agreed to use the BAASIS^© and share back their data)

Location of Data Selection
Basel, Switzerland
Prag, Czech Republic

Duration
Fortlaufend

Description
The Basel Assessment of Adherence to Immunosuppressive Medication Scale (BAASIS^©) was developed to assess adherence to immunosuppressive drugs in transplant recipients. It is increasingly used in transplant and other patient populations.

Developed according to the ABC taxonomy of medication adherence (Vrijens et al., 2012), the BAASIS^© is recommended in the COMMIT guidelines for assessing medication adherence as a 5th vital sign in transplantation (Neuberger et al., 2017).

As part of our on-going efforts to evaluate its psychometric properties (i.e., validity/reliability), this project is reaching out to researchers who have used the BAASIS^© and whose work is relevant to our validation study.
The validity of the BAASIS^© has been analyzed psychometrically in a meta-analysis of individual patient data (Denhaerynck et al., 2023; commentary: Elias et al., 2023).

Predictive validity has been established for critical outcomes such as biopsy-proven graft rejection (Haupenthal et al., 2025) in collaboration with researchers at the University Hospital VIenna.

More information about the BAASIS^© can be obtained on the website: BAASIS – The Basel Assessment of Adherence to immunoSuppressive medIcations Scale© .

The BAASIS^© has been translated into 19 languages and more are in preparations.

From 2020 to November 2025, the BAASIS^© has been used in 101 clinical and 186 research projects, and around another 200 projects were registered before 2020. It makes 487 projects using the BAASIS^© scale worldwide.