During this research a Bayesian Network model was created to determine the probability of a data breach caused by insiders of a health care sector. In addition to this, a data breach assessment tool has been created which can be used to obtain observations for the model. To gather information on the impact of the variables a focus group session with assignments was arranged. To explain the research and the assignments to the participants a presentation was given. The model was validated by sensitivity analyses and performing a data breach assessment in three hospitals.