Accuracy of parents in measuring body temperature with a tympanic thermometer

Robinson, Joan L; Jou, Hsing; Spady, Donald W

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 ≥ 0.5 °C was considered clinically significant. A fever was defined as a temperature ≥ 38.5 °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 °C, and 33% of the readings differed by ≥ 0.5 °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 °C, and 72 % of the readings differed by ≥ 0.5 °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 °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.