Summary: Graphical displays of information have become an important part of modern communications, but surprisingly little research has examined the impact of display format on clinical decision-making in medical contexts. This dissertation describes the implementation and evaluation of several graphical and tabular displays of patient pulmonary and symptom information taken from a lung transplant home monitoring program. The designs for these displays were informed by current theory and experiment regarding 'best practices' for data and information visualization. Software was implemented to take case information and render it as Portable Document Format (PDF) or Scalable Vector Graphics (SVG) files in a web browser. Clinician readers reviewed randomly-ordered, retrospective cases in each of several display formats (including graphical, graphical interactive, and tabular) and determined whether they showed signs of infection or graft rejection. Differences in decision accuracy between formats were analyzed using receiver operating characteristic (ROC) curve analysis, adapted from radiology studies assessing differential accuracies among imaging modalities. Decision times and reader preferences were also recorded and analyzed. No statistically significant differences were found with respect to decision accuracy, and several possible explanations for these findings are discussed. However, the graphical displays yielded up to 25% faster decision times than numerical tables, presumably because the graphical displays more efficiently organize clinically relevant information, with less cognitive burden on the reader. In terms of preference, readers overwhelmingly preferred the graphical formats, particularly the interactive displays. In conclusion, it is argued that graphical, interactive displays of patient data can be well-accepted and efficacious tools in clinical practice, whether for transplant care, or any care involving the assessment of large bodies of time-oriented, multivariable data.