A Graphical Device to Represent the Outcomes of a Logistic Regression Analysis

BACKGROUND. Ongoing research on the best way to diagnose prostate cancer has yielded and will continue to yield vast amounts of information. Based on, for example, information from prostate cancer screening trials models have been made that enable urologists to predict which man has prostate cancer on the basis of pre-biopsy data. In patients with screen detected prostate cancer, the presence of indolent disease can now be identified with reasonable certainty by a different model. For these men active surveillance may be a better option than aggressive treatment with its possible side effects as impotence, incontinence and bowel damage. Both models mentioned above are logistic regression models. Nomograms enable their use in daily clinical practice. METHODS. Nomograms require the memorization and addition of intermediate results. We aimed to design a device that has the same function as a nomogram without this draw back. RESULTS. A new device that resembles a circular slide rule was developed and is currently being tested in prostate cancer diagnosis and in prostate cancer patient counseling. CONCLUSIONS. The new device has identical functionality to the nomogram without the drawback of the latter. The application of the device is not limited to the field of prostate cancer research. Prostate 68: 1674-1680, 2008. (C) 2008 Wiley-Liss, Inc.