A longitudinal study to identify the influence of quality of chronic care delivery on productive interactions between patients and (teams of) healthcare professionals within disease management programmes

__Abstract__ Objective: The chronic care model is an increasingly used approach to improve the quality of care through system changes in care delivery. While theoretically these system changes are expected to increase productive patient-professional interaction empirical evidence is lacking. This study aims to identify the influence of quality of care on productive patient-professional interaction. Setting: Longitudinal study in 18 Dutch regions. Participants: Questionnaires were sent to all 5076 patients participating in 18 Disease Management Programmes (DMPs) in 2010 (2676 (53%) respondents). One year later (T1), 4693 patients still participating in the DMPs received a questionnair