Background: The ability to take a patient's temperature quickly, easily, and accurately is desirable in a variety of situations. However, in order to have confidence in the values obtained, it is important to quantify the reliability of the measurement.
Purpose: The purpose of this study, therefore, was to determine the reliability of temperature measurements obtained by infra-red tympanic membrane thermometers.
Method: This study examined intra-tester, inter-tester and inter-instrument reliability using two commercially available tympanic membrane thermometers. Forty-four college students (mean age 20.2 +/- 3.6 yr) had their tympanic membrane temperature taken by two investigators, each using two different instruments (ThermoScan Pro-1 and FirstTemp Genius).
Results: The results indicated a statistically significant difference between testers for each instrument. Similarly, there was a significant statistical difference between instruments within each tester. Correlations were moderately high (r = 0.66-0.88) between testers for each instrument, whereas correlations within instruments varied considerably between testers (r = 0.35-0.78). The intra-tester reliability was good for both testers using both instruments with all coefficients of variation (CV) less than 2%. Statistically significant differences were found between testers for each instrument and between instruments for each tester. A 2 x 2 ANOVA revealed a significant main effect for Tester and a significant Tester x Instrument interaction.
Conclusion: We conclude that individual investigators are able to obtain reliable temperature measures when using either the FirstTemp Genius or ThermoScan Pro-1 instruments under resting laboratory conditions. However, inter-tester and inter-instrument reliability should be considered when collecting or comparing data.