  Demand for health care is constantly increasing due to the ongoing
demographic change, while at the same time health service providers face
difficulties in finding skilled personnel. This creates pressure on health care
systems around the world, such that the efficient, nationwide provision of
primary health care has become one of society's greatest challenges. Due to the
complexity of health care systems, unforeseen future events, and a frequent
lack of data, analyzing and optimizing the performance of health care systems
means tackling a wicked problem. To support this task for primary care, this
paper introduces the hybrid agent-based simulation model SiM-Care. SiM-Care
models the interactions of patients and primary care physicians on an
individual level. By tracking agent interactions, it enables modelers to assess
multiple key indicators such as patient waiting times and physician
utilization. Based on these indicators, primary care systems can be assessed
and compared. Moreover, changes in the infrastructure, patient behavior, and
service design can be directly evaluated. To showcase the opportunities offered
by SiM-Care and aid model validation, we present a case study for a primary
care system in Germany. Specifically, we investigate the effects of an aging
population, a decrease in the number of physicians, as well as the combined
effects.
