Knowledge and Attitudes of Emergency Department Patients Regarding Radiation Risk of CT: Effects of Age, Sex, Race, Education, Insurance, Body Mass Index, Pain, and Seriousness of Illness

OBJECTIVE. The purpose of this study was to assess knowledge and attitudes about radiation from CT among emergency department patients with symptoms prompting CT who were stratified on the basis of demographic variables, pain, and perceived illness. SUBJECTS AND METHODS. This survey study was based on three knowledge and three attitude questions asked of patients who underwent any CT examination from June 23 through July 31, 2008. Data were analyzed with chi-square for categoric data and the Student's t test or analysis of variance for continuous data. RESULTS. The survey was completed by 383 patients (mean age, 48 +/- 18 years; 60% women; 40% black; 52% white; 8% other race). In answering the three knowledge-based questions, 79% and 83% of patients correctly estimated their risk of cancer from chest radiography and CT, respectively, as none, small, or very small. Patients who were white, more educated, and had lower pain scores were more likely to be correct. Only 34% of all patients correctly thought that CT gave more radiation than chest radiography; the more educated patients were more likely to be correct. In answering the three attitude questions, 74% of patients believed having their condition diagnosed with CT was more important than worrying about radiation. Patients preferred a better test with more radiation, although 68% wanted their physician to take the time to discuss the risk and benefits rather than using their judgment to order the best test. Privately insured patients preferred to have their condition diagnosed with CT rather than worry about radiation. Blacks and patients with less pain wanted the risks and benefits explained at the expense of time. Whites preferred a more definitive test at the expense of more radiation. CONCLUSION. Patients did not estimate the risk of development of cancer from their imaging examinations as high and were more concerned about having their condition diagnosed with CT than about the risk of future cancer. Knowledge and attitudes differed by age, race, education, insurance status, and pain level but not by sex, body mass index, or perceived seriousness of condition.