Accuracy of parents in measuring body temperature with a tympanic thermometer.

BACKGROUND: It is now common for parents to measure tympanic temperatures in children. The objective of this study was to assess the diagnostic accuracy of these measurements.

METHODS: Parents and then nurses measured the temperature of 60 children with a tympanic thermometer designed for home use (home thermometer). The reference standard was a temperature measured by a nurse with a model of tympanic thermometer commonly used in hospitals (hospital thermometer). A difference of >or= 0.5 degrees C was considered clinically significant. A fever was defined as a temperature >or= 38.5 degrees C.

RESULTS: The mean absolute difference between the readings done by the parent and the nurse with the home thermometer was 0.44 +/- 0.61 degrees C, and 33% of the readings differed by >or= 0.5 degrees C. The mean absolute difference between the readings done by the parent with the home thermometer and the nurse with the hospital thermometer was 0.51 +/- 0.63 degrees C, and 72 % of the readings differed by >or= 0.5 degrees C. Using the home thermometer, parents detected fever with a sensitivity of 76% (95% CI 50-93%), a specificity of 95% (95% CI 84-99%), a positive predictive value of 87% (95% CI 60-98%), and a negative predictive value of 91% (95% CI 79-98 %). In comparing the readings the nurse obtained from the two different tympanic thermometers, the mean absolute difference was 0.24 +/- 0.22 degrees C. Nurses detected fever with a sensitivity of 94% (95 % CI 71-100 %), a specificity of 88% (95% CI 75-96 %), a positive predictive value of 76% (95% CI 53-92%), and a negative predictive value of 97% (95%CI 87-100 %) using the home thermometer. The intraclass correlation coefficient for the three sets of readings was 0.80, and the consistency of readings was not affected by the body temperature.

CONCLUSIONS: The readings done by parents with a tympanic thermometer designed for home use differed a clinically significant amount from the reference standard (readings done by nurses with a model of tympanic thermometer commonly used in hospitals) the majority of the time, and parents failed to detect fever about one-quarter of the time. Tympanic readings reported by parents should be interpreted with great caution.