# Accuracy and Precision of Third‐Generation Tympanic Thermometers With Varying Calibration Intervals: A Multicenter Cross‐Sectional Study

## TL;DR

This study evaluates the accuracy and reliability of a third-generation tympanic thermometer and finds that its accuracy declines if not calibrated within six months.

## Contribution

The study identifies calibration intervals as a critical factor affecting the accuracy of third-generation tympanic thermometers.

## Key findings

- The tympanic thermometer showed excellent intra- and interobserver reliability.
- The device consistently underestimated body temperature by an average of 0.3°C.
- Calibration intervals over six months significantly reduced measurement accuracy.

## Abstract

To evaluate intra‐ and interoperator reliability and accuracy of the third‐generation tympanic thermometer (GeniusTM3) and to explore the relationship between measurement error and calibration intervals of the tympanic thermometer.

Open‐label, pragmatic multicenter cross‐sectional study.

The study was carried out in intensive care units and operating theaters across five hospitals in Northern Italy. Patients of any age admitted to intensive care units or undergoing surgical procedures in operating theaters between December 2023 and October 2024 were enrolled. Two trained nurses independently took the temperature three consecutive times using the same tympanic thermometer. Core temperature was measured using one of the gold standard methods. The measurement error was calculated as the difference between the gold standard measurement and the measurement made with the tympanic temperature.

A total of 550 patients were enrolled. The precision of the tympanic thermometer was shown to be excellent in both intraobserver and interobserver reliability. The tympanic thermometer consistently underestimated body temperature, with a mean measurement error of 0.3°C and a limits of agreement of ±1.3°C. The generalized linear model (GLM) showed calibration interval, recruiting hospital, and the variable defined by their interaction as factors that were independently and statistically significant predictors of accuracy variation.

The third‐generation tympanic thermometer (GeniusTM3) represents a reliable tool for ensuring high accuracy in terms of both intraoperator and interoperator concordance. However, the accuracy of the device has been significantly affected by the timing of the calibration: a calibration interval of more than 6 months results in a significant deterioration in accuracy.