The actor-partner interdependence model in shared decision-making: an illustrative example of its application to the physician-patient dyad in primary care consultations.

Objectives: We applied the actor-partner interdependence model, a method used to evaluate the relationship process between two related persons, to patient-physician data about the effect of shared decision-making behaviors on patient and physician uncertainty. We discuss measurement and interpretation problems.

Study Design And Setting: The EXACKTE project was a cross-sectional study of 263 unique patient-physician dyads in 17 primary care clinics in Canada. Participants independently completed self-administered questionnaires postconsultation to measure patients' and physicians' perceptions of shared decision-making behaviors and their uncertainty about whether the decision was the best one for the patient. We used the actor-partner interdependence model to explore the effect of shared decision-making behaviors on patient and physician uncertainty.

Results: Application of the actor-partner interdependence model to our data showed significant actor effects only. Our exploratory analysis suggested that an appropriate dyadic pattern for this context would be the couple-oriented model.

Conclusion: Each actor's perception of the physicians' shared decision-making behaviors appeared only to affect their own uncertainty (actor effects), but the questionnaire may have been inadequate for identifying partner effects. Researchers should further explore using the actor-partner interdependence model to analyze actor-partner interdependence in the physician-patient relationship, and format questions tailored precisely to the model.