Accuracy of Non-contact Infrared Thermometry Versus Rectal Thermometry in Young Children Evaluated in the Emergency Department for Fever

Objective: We evaluated the accuracy of a non-contact infrared thermometer compared with a rectal thermometer. Methods: Two hundred patients, ages 1 month to 4 years, were included in the study. Each child underwent contemporaneous standard rectal thermometry and mid forehead non-contact infrared thermometry. Clinical features, including chief complaint, recently administered antipyretic agents, and ambient temperature at the time of measurement, were included. Analysis: Linear models were used to compare agreement between the 2 techniques, as well as to determine bias of infrared thermometry at different rectal temperatures. Multivariate linear models were used to evaluate the impact of clinical variables and ambient temperature. Results: A linear relationship between rectal and infrared temperature measurements was observed; however, the coefficient of determination (r²) value between was only 0.48 (P < 0.01). Infrared thermometry tended to overestimate the temperature of afebrile children and underestimate the temperature of febrile patients (P < .01). Ambient temperature and child age did not affect the accuracy of the device. Conclusion: In this study, non-contact infrared thermometry did not sufficiently agree with rectal thermometer to indicate its routine use.