Proper use of noncontact infrared thermometry for temperature screening during COVID-19

Among the myriad of challenges healthcare institutions face in dealing with coronavirus disease 2019 (COVID-19), screening for the detection of febrile persons entering facilities remains problematic, particularly when paired with CDC and WHO spatial distancing guidance. Aggressive source control measures during the outbreak of COVID-19 has led to re-purposed use of noncontact infrared thermometry (NCIT) for temperature screening. This study was commissioned to establish the efficacy of this technology for temperature screening by healthcare facilities. We conducted a prospective, observational, single-center study in a level II trauma center at the onset of the COVID-19 outbreak to assess (i) method agreement between NCIT and temporal artery reference temperature, (ii) diagnostic accuracy of NCIT in detecting referent temperature [Formula: see text] and ensuing test sensitivity and specificity and (iii) technical limitations of this technology. Of 51 healthy, non-febrile, healthcare workers surveyed, the mean temporal artery temperature was [Formula: see text] ([Formula: see text] confidence interval (CI) = [Formula: see text]). Mean NCIT temperatures measured from [Formula: see text], [Formula: see text], and [Formula: see text] distances were [Formula: see text] [Formula: see text], [Formula: see text] [Formula: see text], and [Formula: see text] [Formula: see text], respectively. From statistical analysis, the only method in sufficient agreement with the reference standard was NCIT at [Formula: see text]. This demonstrated that the device offset (mean temperature difference) between these methods was [Formula: see text] ([Formula: see text]) with 95% of measurement differences within [Formula: see text] ([Formula: see text]) and [Formula: see text] ([Formula: see text]). By setting the NCIT screening threshold to [Formula: see text] at [Formula: see text], we achieve diagnostic accuracy with [Formula: see text] test sensitivity and specificity for temperature detection [Formula: see text] by reference standard. In comparison, reducing this screening criterion to the lower limit of the device-specific offset, such as [Formula: see text], produces a highly sensitive screening test at [Formula: see text], which may be favorable in high-risk pandemic disease. For future consideration, an infrared device with a higher distance-to-spot size ratio approaching 50:1 would theoretically produce similar results at [Formula: see text], in accordance with CDC and WHO spatial distancing guidelines.