In this thesis we have studied the extent of guideline adherence in the management of NST ACS patients with emphasis on the use of cardiac risk scores in clinical practice. Besides the actual use of risk scores in clinical practice, determinants for suboptimal cardiac risk score use were studied on a patient-, healthcare provider- and organizational-level. Furthermore, the impact of different components of clinical information, including risk score outcomes, on cardiologists’ decision-making regarding performing coronary angiography was studied.