A number of evaluations of models of integrated care have not produced the expected result of reduced hospital admissions, and in some cases have even found people receiving integrated care services using hospitals more than matched controls. We tested three hypotheses for these surprising results with a group of 50 integrated care experts in a seminar: (1) problems with the model; (2) problems of implementation; and (3) problems of evaluation. Our group of experts did not rule out any of these hypotheses and came up with some advice as to manage these issues. For example, model designers should rigorously test the underlying logic; commissioners should seek out advice from experts and patients/professionals; and evaluators should choose outcomes wisely, use mixed methods approaches, and provide regular feedback loops to implementation sites. Evaluating integrated care is a skilled task that requires multiple approaches in terms of the design and implementation of the models. National research funders or other appropriate bodies might consider developing an advisory service to provide support to local systems planning evaluations
