Development and Validation of the Behavioral Determinants of Deprescribing Questionnaire (BDDQ)

Deprescribing is a strategy to optimize medication use. While a patient's willingness to engage in deprescribing depends on several factors, the literature on the subject relies almost exclusively on questionnaires that only measure patients' attitudes towards deprescribing. This study used health behavior theories (HBTs) to develop a questionnaire that measures a larger range of psychological determinants of patients' deprescribing participation.

A draft self-report questionnaire was developed based on a recent systematic review. It measures 11 dimensions representing the main HBT-derived determinants of patients' participation in deprescribing, as well as previous experience with deprescribing, current behavior, and intention to participate in deprescribing. Face validity was assessed via small group discussions involving 10 healthcare professionals and 12 older people. Construct validity was assessed in a sample of 103 participants, using exploratory factor analysis (EFA). Internal consistency was assessed via Cronbach's alpha and Omega coefficient.

The EFA confirmed 11 dimensions explaining 67,15% of the total variance but revealed poor factor loadings for some items and low Cronbach alpha values (<.50) for three factors. Removal of items and factors resulted in a final questionnaire of 25 items measuring 8 conceptually relevant dimensions, with internal consistencies ranging between.55 and.77: perceived necessity of medication, perceived risks of medication, perceived norms regarding medication use, perceived effects of deprescribing, perceived difficulty of deprescribing, perceived social support, healthcare system support, and medication literacy.

A conceptually based and psychometrically validated questionnaire was developed measuring the main behavioral determinants of older patients' participation in deprescribing, allowing a comprehensive investigation of intentions and behavior.