Validity of Wrist and Forehead Temperature in Temperature Screening in the General Population During the Outbreak of 2019 Novel Coronavirus: a prospective real-world study

Chen, Ge; Xie, Jiarong; Dai, Guangli; Zheng, Peijun; Hu, Xiaqing; Lu, Hongpeng; Xu, Lei; Chen, Xueqin; Chen, Xiaomin

Aims: Temperature screening is important in the population during the outbreak of 2019 Novel Coronavirus (COVID-19). This study aimed to compare the accuracy and precision of wrist and forehead temperature with tympanic temperature under different circumstances. Methods: We performed a prospective observational study in a real-life population. We consecutively collected wrist and forehead temperatures in Celsius (C) using a non-contact infrared thermometer (NCIT). We also measured the tympanic temperature using a tympanic thermometers (IRTT) and defined fever as a tympanic temperature ≥37.3C. Results: We enrolled a total of 528 participants including 261 indoor and 267 outdoor participants. We divided outdoor participants into four types according to their means of transportation to the hospital as walk, bicycle, electric vehicle, car, and inside the car. Under different circumstance, the mean difference ranged from -1.72 to -0.56C in different groups for the forehead measurements, and -0.96 to -0.61C for the wrist measurements. Both measurements had high fever screening abilities in inpatients (wrist: AUC 0.790; 95% CI: 0.725-0.854, P <0.001; forehead: AUC 0.816; 95% CI: 0.757-0.876, P <0.001). The cut-off value of wrist measurement for detecting tympanic temperature ≥37.3C was 36.2C with a 86.4% sensitivity and a 67.0% specificity, and the best threshold of forehead measurement was also 36.2C with a 93.2% sensitivity and a 60.0% specificity. Conclusions: Wrist measurement is more stable than forehead measurement under different circumstance. Both measurements have great fever screening abilities for indoor patients. The cut-off value of both measurements was 36.2C.