Risks associated with the use of IV contrast material: analysis of patients' awareness

Opinions differ on the need to obtain informed consent for IV administration of contrast material. If the potential risks are common knowledge among most patients, the need for informed consent is reduced. The purpose of this study was to assess patients' baseline knowledge of the risks associated with use of IV contrast material.

This study included 150 consecutive outpatients who had radiographic studies (CT or excretory urography) requiring use of IV contrast material. Before the procedure, patients were asked to complete a 10-question questionnaire assessing their understanding of the risks associated with the use of contrast material. Questions concerned the nature of their test and the reasons for and risks of contrast material. Analysis was done with Fisher's exact chi 2-test of association and Wilcoxon's two-sample test.

On average, the patients performed significantly better on this questionnaire than if they had randomly picked each answer, indicating that the average patient has acquired some information about IV contrast material. However, the mean score was 51%, demonstrating that the average patient is not knowledgeable about all risks associated with the use of IV contrast material. We found no differences associated with sex or age. Patients with more than a high school level of education and who had previously received contrast material scored better, although they still correctly answered only 56% and 54% of the questions, respectively.

Information about the risks associated with use of IV contrast material cannot be considered common knowledge among the general population of patients.