Accuracy, precision and diagnostic accuracy of oral thermometry in pediatric patients

Purpose

To determine the accuracy and precision of oral thermometry in pediatric patients, along with its sensitivity and specificity for detecting fever and hypothermia, with rectal thermometry as reference standard.

Design and methods

This method-comparison study enrolled patients aged between 6 and 17 years, admitted to the surgical ward during a 21-month period. KD-2150 and IVAC Temp Plus II were used for oral and rectal temperature measurements respectively. Fever and hypothermia were defined as core temperature ≥38.0 °C and ≤ 35.9 °C respectively. Accuracy and precision of oral thermometry were determined by the Bland-Altman method. Sensitivity, specificity, positive and negative predictive value, and correct classification of oral temperature cutoffs for detecting fever and hypothermia were calculated.

Results

Based on power analysis, 100 pediatric patients were enrolled. The mean difference between oral and rectal temperatures was −0.34 °C, with 95 % limits of agreement ranging between −0.52 and −0.16. Sensitivity and specificity of oral thermometry for detecting fever were 0.50 and 1.0 respectively; its sensitivity and specificity for detecting hypothermia were 1.0 and 0.88 respectively. The oral temperature value of 37.6 °C provided excellent sensitivity for detecting fever, while the value of 35.7 °C provided optimal sensitivity and specificity for detecting hypothermia.

Conclusions

Oral thermometry had low sensitivity for detecting fever and suboptimal specificity for detecting hypothermia; thus, temperature values <38.0 °C and <36.0 °C cannot exclude fever and confirm hypothermia respectively with high certainty.

Practice implications

Diagnostic accuracy of oral thermometry can be improved by the use of oral temperature thresholds <38.0 °C for detecting fever and <35.9 °C for detecting hypothermia.