Measuring the clinical utility of a diagnostic test involves evaluating its impact on patient outcomes, clinical decision-making, and healthcare resource utilization. Determining clinical utility requires accessing patient medical history and outcomes data. These studies involve enrolling patients undergoing diagnostic tests and tracking their clinical outcomes. Researchers can determine the test's clinical utility by comparing the outcomes of patients who receive the diagnostic test to those who do not. These outcomes include benefits and harm. The highest level of evidence to support clinical utility determinations may be obtained from clinical trials. However, clinical laboratories are often not involved in clinical trials, and laboratory specialists may not be experienced in conducting such trials. Many established laboratory tests have never had clinical utility determined. Prospective studies assessing a diagnostic test's impact on clinical outcomes may require long-term patient monitoring, which is problematic. This paper presents methods that may be used to assess clinical utility.