Accuracy of tympanic and forehead thermometers in private paediatric practice

Abstract

To compare infrared tympanic and infrared contact forehead thermometer measurements with traditional rectal digital thermometers. A total of 254 children (137 girls) aged one to 24 months (median 7 months) consulting a private paediatric practice because of fever were prospectively recruited. Body temperature was measured using the three different devices. The median and interquartile range for rectal, tympanic and forehead thermometers were 37.6 (37.1-38.4)°C, 37.5 (37.0-38.1)°C and 37.5 (37.1-37.9)°C, respectively (p < 0.01). The limits of agreement in the Bland-Altman plots were -0.73 to +1.04°C for the tympanic thermometer and -1.18 to +1.64°C for the forehead thermometer. The specificity of both the tympanic and forehead thermometers for detecting fever above 38°C was good, but sensitivity was low. Forehead measurements were susceptible to the use of a radiant warmer. Both the tympanic and forehead devices recorded lower temperatures than the rectal thermometers. The limits of agreement were particularly wide for the forehead thermometer and considerable for the tympanic thermometer. In the absence of valid alternatives, because of the ease to use and little degree of discomfort, tympanic thermometers can still be used with some reservations. Forehead thermometers should not be used in paediatric practice.