Dr. Deppen is a clinical epidemiologist with extensive experience in the validation and clinical evaluation of imaging, biomarkers, and diagnostic tests, cost effectiveness and implementation science with a focus on the diagnosis of lung nodules. His modeling expertise includes geospatial, predictive risk, quantification of evidence and longitudinal modeling. This focus on issues relevant to the evaluation of indeterminate lung nodules has resulted in groundbreaking work that has changed current guidelines for nodule diagnosis and quantified the limitations of our imaging technology. With his expertise in economics, he has helped address questions regarding diagnostic imaging effectiveness and the cost effectiveness of strategies to improve HPV vaccination rates in a randomized implementation trial. As a member of the TREAT group at Vanderbilt University Medical Center with Drs. Grogan, Massion and Aldrich, we have pursued improving the non-invasive diagnosis of lung nodules through biomarker development and validation.