A theory-based evaluation framework for primary care: setting the stage to evaluate the "Comparison of Models of Primary Health Care in Ontario" project

Primary care reform has triggered a flood of demonstration projects across Canada that need to be evaluated. This presents a challenge to an evaluator who is uncertain about how to convince clinical investigators to think beyond traditional research designs toward using evaluation approaches. The purpose of this article is to describe the application and benefits of using a theory-based evaluation framework for a large evaluation of four unique models of primary care delivery in Ontario, the Comparison of Models of Primary Health Care in Ontario (COMP-PC) project.