Clinical accuracy and agreement between tympanic and forehead body temperature measurements for screening of patients with COVID-19

Evaluation of concordance in estimation of excess mortality due to COVID-19 pandemic

BACKGROUND

The World Health Organization (WHO) kept track of COVID-19 data at country level daily during the pandemic that included the number of tests, infected cases and fatalities. This daily record was susceptible to change depending on the time and place and impacted by underreporting. In addition to reporting cases of excess COVID-19-related deaths, the WHO also provided estimates of excess mortality based on mathematical models.

OBJECTIVE

To evaluate the WHO reported and model-based estimate of excess deaths to determine the degree of agreement and universality.

METHODOLOGY

Epidemiological data gathered from nine different countries between April 2020 and December 2021 are used in this study. These countries are India, Indonesia, Italy, Russia, United Kingdom, Mexico, the United States, Brazil and Peru and each of them recorded more than 1.5 million deaths from COVID-19 during these months. Statistical tools including correlation, linear regression, intraclass correlation and Bland-Altman plots are used to assess the degree of agreement between reported and model-based estimates of excess deaths.

RESULTS

The WHO-derived mathematical model for estimating excess deaths due to COVID-19 was found to be appropriate for only four of the nine chosen countries, namely Italy, United Kingdom, the United States and Brazil. The other countries showed proportional biases and significantly high regression coefficients.

CONCLUSION

The study revealed that, for some of the chosen nations, the mathematical model proposed by the WHO is practical and capable of estimating the number of excess deaths brought on by COVID-19. However, the derived approach cannot be applied globally.

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.

Agreement of infrared ear temperature with nasopharyngeal temperature and diagnostic performance on hypothermia in general anesthetized patients

BACKGROUND

Infrared ear thermometry is widely used in clinical practice due to its noninvasive, convenient, and quick sampling. However, its accuracy and feasibility in anesthetized patients have not yet been established.

METHODS

We conducted this cross-sectional study to evaluate the agreement between infrared ear temperature and nasopharyngeal temperature in general anesthetized patients and its performance in intraoperative hypothermia, defined as nasopharyngeal temperature <36°C. Adult female patients who underwent gynecological surgery under general anesthesia were enrolled in this study. Infrared ear temperature by Braun ThermoScan PRO 4000 (Braun GmbH, Kronberg, Germany) and nasopharyngeal temperature were measured simultaneously before, during, and after surgery. The agreement between the two temperatures was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. The diagnostic performance of the infrared ear thermometer for hypothermia was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

Fifty-six patients with 168 pairs of simultaneous infrared ear and nasopharyngeal temperatures were included in this analysis. The mean infrared ear temperature was consistently higher than the nasopharyngeal temperature throughout surgery, but the differences were small (0.22, 0.13, and 0.06°C before, during, and after surgery, respectively). The ICC between the two temperatures before, during, and after surgery was 0.70, 0.75, and 0.80, respectively, and 93.5% of the differences fell within the 95% limits of agreement of ±0.5°C. An infrared ear thermometer had high diagnostic accuracy for hypothermia, with an area under the ROC curve of 0.95 (95% confidence interval [CI], 0.92-0.98). The cutoff of infrared ear temperature for hypothermia was 36.2°C with a sensitivity of 0.89 (95% CI, 0.71-0.98) and a specificity of 0.87 (95% CI, 0.81-0.92).

CONCLUSION

The infrared ear temperature is in good agreement with the nasopharyngeal temperature in general anesthetized patients without hyperthermia and has high performance for detecting hypothermia. An infrared ear thermometer can be a diagnostic tool for intraoperative hypothermia.

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

Purpose

Fever is one of the most typical clinical symptoms of coronavirus disease 2019 (COVID-19), and non-contact infrared thermometers (NCITs) are commonly used to screen for fever. However, there is a lack of authoritative data to define a “fever” when an NCIT is used and previous studies have shown that NCIT readings fluctuate widely depending on ambient temperatures and the body surface site screened. The aim of this study was to establish cut-off points for normal temperatures of different body sites (neck, forehead, temples, and wrist) and investigate the accuracy of NCITs at various ambient temperatures to improve the standardization and accuracy of fever screening.

Patients and Methods

A prospective investigation was conducted among 904 participants in the outpatient and emergency departments of Chengdu Women’s and Children’s Central Hospital. Body temperature was measured using NCITs and mercury axillary thermometers. A receiver operating characteristic curve was used to determine the accuracy of body temperature detection at the four body surface sites. Data on participant characteristics were also collected.

Results

Among the four surface sites, the neck temperature detection group had the highest accuracy. When the neck temperature was 37.35°C as the optimum fever diagnostic threshold, the sensitivity was 0.866. The optimum fever diagnostic thresholds for forehead, temporal, and wrist temperature were 36.65°C, 36.65°C, and 36.75°C, respectively. Moreover, triple neck temperature detection had the highest sensitivity, up to 0.998, whereas the sensitivity of triple wrist temperature detections was 0.949. Notably, the accuracy of NCITs significantly reduced when the temperature was lower than 18°C.

Conclusion

Neck temperature had the highest accuracy among the four NCIT temperature measurement sites, with an optimum fever diagnostic threshold of 37.35°C. Considering the findings reported in our study, we recommend triple neck temperature detection with NCITs as the fever screening standard for COVID-19.