Objectives: We explored the history and conceptual trends of outcomes research.
Methods: We described different aspects of this field, after dividing it into conceptually distinct strata.
Results: Outcomes research can be divided into macro, meso and micro levels. Each level is further subdivided. Macro-level research targets cost and health care utilization, as well as racial, ethnic and geopolitical population health determinants. Meso-level studies address effectiveness, variability, disease impact, clinical modeling and program evaluation studies. Finally, micro-level studies address all aspects of direct patient-clinician decision-making.
Conclusions: An explosion of outcomes research has occurred in the past decades. Wide access to information technology, data sharing and collaborative efforts between researchers represent some of the ingredients that did and will continue to fuel that growth.