Reliability of Non-Contact Infrared Thermometers for Fever Screening Under COVID-19

Comparison of two non-invasive body temperature measurement methods for the detection of febrile neutropenia in children with cancer

BACKGROUND

This study was conducted to compare the accuracy of two noninvasive thermometers (axillary and infrared non-contact forehead thermometer) in measuring core temperature compared to the gold standard oral thermometer in the detection of fever in pediatric cancer patients with febrile neutropenia.

METHODS

The study was conducted with a single group of 42 children with febrile neutropenia between 23 December 2020 and 25 January 2023 in the pediatric hematology and oncology clinic of a training and research hospital, which provides a specialized environment for both medical education and advanced scientific research in the field of pediatric hematology and oncology. The participants' body temperature was measured with an oral, axillary, and non-contact infrared forehead thermometer immediately after admission to the clinic and at 5 and 10 min after admission. The inter-rater agreement for each method and inter-method agreement between axillary and non-contact infrared temperature readings and oral readings were analyzed for each time point using intraclass correlation coefficients (ICC).

RESULTS

The children in the study had a mean age of 11.62 ± 3.00 years and 28 (66.7%) were boys, 19 (45.2%) were younger children (5-10 years of age), and 23 (54.8%) were adolescents (11-16 years of age). In the analysis of agreement between the thermometers at admission and at 5 and 10 min after admission in children with febrile neutropenia, the highest agreement was between the oral and axillary thermometers (ICC: 0.584, 0.835, 0.536, respectively) and the lowest agreement was between the oral and non-contact infrared thermometers (ICC: 0.219, 0.022, 0.473, respectively).

CONCLUSION

Compared to orally measured body temperature, axillary temperature readings showed better agreement than non-contact infrared temperature readings from the forehead in pediatric patients with febrile neutropenia.

PRACTICE IMPLICATIONS

The research findings may guide nurses and families caring for pediatric patients with febrile neutropenia and should contribute to the prevention of false findings of fever and the reduction of its adverse consequences.

Non-Contact Infrared Thermometers and Thermal Scanners for Human Body Temperature Monitoring: A Systematic Review

In recent years, non-contact infrared thermometers (NCITs) and infrared thermography (IRT) have gained prominence as convenient, non-invasive tools for human body temperature measurement. Despite their widespread adoption in a range of settings, there remain questions about their accuracy under varying conditions. This systematic review sought to critically evaluate the performance of NCITs and IRT in body temperature monitoring, synthesizing evidence from a total of 72 unique settings from 32 studies. The studies incorporated in our review ranged from climate-controlled room investigations to clinical applications. Our primary findings showed that NCITs and IRT can provide accurate and reliable body temperature measurements in specific settings and conditions. We revealed that while both NCITs and IRT displayed a consistent positive correlation with conventional, contact-based temperature measurement tools, NCITs demonstrated slightly superior accuracy over IRT. A total of 29 of 50 settings from NCIT studies and 4 of 22 settings from IRT studies achieved accuracy levels within a range of ±0.3 °C. Furthermore, we found that several factors influenced the performance of these devices. These included the measurement location, the type of sensor, the reference and tool, individual physiological attributes, and the surrounding environmental conditions. Our research underscores the critical need for further studies in this area to refine our understanding of these influential factors and to develop standardized guidelines for the use of NCITs and IRT.

Optimal diagnostic fever thresholds using non-contact infrared thermometers under COVID-19

Fever screening is an effective method to detect infectors associated with different variants of coronavirus disease 2019 (COVID-19) based on the fact that most infectors with COVID-19 have fever symptoms. Non-contact infrared thermometers (NCITs) are widely used in fever screening. Nevertheless, authoritative data is lacking in defining "fever" at different body surface sites when using NCITs. The purpose of this study was to determine the optimal diagnostic threshold for fever screening using NICTs at different body surface sites, to improve the accuracy of fever screening and provide theoretical reference for healthcare policy. Participants (n = 1860) who were outpatients or emergency patients at Chengdu Women's and Children's Central Hospital were recruited for this prospective investigation from March 1 to June 30, 2021. NCITs and mercury axillary thermometers were used to measure neck, temple, forehead and wrist temperatures of all participants. Receiver operating characteristic curves were used to reflect the accuracy of NCITs. Linear correlation analysis was used to show the effect of age on body temperature. Multilinear regression analysis was used to explore the association between non-febrile participant's covariates and neck temperature. The mean age of participants was 3.45 ± 2.85 years for children and 28.56 ± 7.25 years for adults. In addition 1,304 (70.1%) participants were children (≤12), and 683 (36.7%) were male. The neck temperature exhibited the highest accuracy among the four sites. Further the optimal fever diagnostic thresholds of NCITs at the four body surface measurement sites were neck (36.75 °C, sensitivity: 0.993, specificity: 0.858); temple (36.55 °C, sensitivity: 0.974, specificity: 0.874); forehead (36.45 °C, sensitivity: 0.961, specificity: 0.813); and wrist (36.15 °C, sensitivity: 0.951, specificity: 0.434). Based on the findings of our study, we recommend 36.15, 36.45, 36.55, and 36.75 °C as the diagnostic thresholds of fever at the wrist, forehead, temple and neck, respectively. Among the four surface sites, neck temperature exhibited the highest accuracy.

Clinical Accuracy of Non-Contact Forehead Infrared Thermometer Measurement in Children: An Observational Study

We evaluated the clinical reliability and utility of temperature measurements using no-contact forehead infrared thermometers (NCFITs) by comparing their temperature measurements with those obtained using infrared tympanic thermometers (IRTTs) in children. In this observational, prospective, and cross-sectional study, we enrolled 255 children (aged 1 month to 18 years) from the pediatric surgery ward at a tertiary medical center in Korea. The mean age of the children was 9.05 ± 5.39 years, and 54.9% were boys. The incidence rate of fever, defined as an IRTT reading of ≥38.0 °C, was 15.7%. The ICC coefficient for the assessment of agreement between temperatures recorded by the NCFIT and IRTT was 0.87, and the κ-coefficient was 0.83. The bias and 95% limits of agreement were 0.15 °C (−0.43 to 0.73). For an accurate diagnosis of fever (≥38 °C), the false-negative rate was much lower, but the false-positive rate was higher, especially in 6-year-old children. Therefore, NCFITs can be used to screen children for fever. However, a secondary check is required using another thermometer when the child’s temperature is >38 °C. NCFITs are proposed for screening but not for measuring the temperature. For the latter, an accurate and reliable thermometer shall be used.

A Novel Non-Invasive Thermometer for Continuous Core Body Temperature: Comparison with Tympanic Temperature in an Acute Stroke Clinical Setting

There is a growing research interest in wireless non-invasive solutions for core temperature estimation and their application in clinical settings. This study aimed to investigate the use of a novel wireless non-invasive heat flux-based thermometer in acute stroke patients admitted to a stroke unit and compare the measurements with the currently used infrared (IR) tympanic temperature readings. The study encompassed 30 acute ischemic stroke patients who underwent continuous measurement (Tcore) with the novel wearable non-invasive CORE device. Paired measurements of Tcore and tympanic temperature (Ttym) by using a standard IR-device were performed 3−5 times/day, yielding a total of 305 measurements. The predicted core temperatures (Tcore) were significantly correlated with Ttym (r = 0.89, p < 0.001). The comparison of the Tcore and Ttym measurements by Bland−Altman analysis showed a good agreement between them, with a low mean difference of 0.11 ± 0.34 °C, and no proportional bias was observed (B = −0.003, p = 0.923). The Tcore measurements correctly predicted the presence or absence of Ttym hyperthermia or fever in 94.1% and 97.4% of cases, respectively. Temperature monitoring with a novel wireless non-invasive heat flux-based thermometer could be a reliable alternative to the Ttym method for assessing core temperature in acute ischemic stroke patients.