Validity and reliability of oral temperature compared to ingestible core temperature pill in free-living conditions

TL;DR

This study compares oral and ingestible core temperature measurements in free-living conditions, revealing statistically significant differences and highlighting the complexities in interpreting body temperature data due to thermodynamics and external factors.

Contribution

It provides empirical evidence on the accuracy and reliability of oral versus ingestible core temperature devices in real-world settings.

Findings

MAE of 0.30°C between methods

Significant differences (p<0.001) observed

Complex thermodynamics affect temperature readings

Abstract

Complex thermodynamics of the human body and external factors may cause differences between oral and core body temperatures. We present a 19-subject study where continuous measurements of ingested core temperature pills are compared against spot measurements of oral temperature, both FDA-cleared devices, in free-living conditions. Based on measurements from 419 samples across 19 subjects, MAE of 0.30 +/- 0.26 oC and 95% limits of agreement of -0.60 and 0.90 oC was observed between ingestible pill temperature and oral temperature. These results demonstrate that statistically significant differences (p<0.001) between oral and core temperature may arise in free-living conditions. Such clinically relevant differences in temperature measurements due to complex thermodynamics of heat exchange in the human body, measurement noise, and other external factors show the intricacies of interpreting body temperatures measured at different locations.