USEFULNESS OF FOREHEAD INFRARED THERMOMETERS TO SCREEN PATIENTS FOR FEVER DURING COVID-19 PANDEMIC

Objective: To determine accuracy of infrared thermometer for detection of fever as compared to mercury thermometer. Study Design: Cross sectional study. Place and Duration of Study: Department of Medicine, Combined Military Hospital Peshawar, from May to Jun 2020. Methodology: All willing adult patients reporting to the fever desk were selected by consecutive sampling. Exclu-sion criteria included any dermatological condition affecting forehead and unwillingness. Forehead temperature was first checked twice using Kinlee FT3010 infrared thermometer. Axillary temperature was then recorded using a standard clinical mercury thermometer. Results: There were 538 patients, including 251 (46.65%) males and 287 (53.35%) females, aged 46.76 ± 12.44 years. Median temperatures recorded with infrared and mercury thermometers were 97.00°F (interquartile range: 95.10-97.80°F) and 98.30°F (interquartile range: 98.00-98.90°F) respectively (p<0.001). Intra-class correlation was 0.143 (95% CI-0.052, 0.323). There was a weak to moderate correlation (R: 0.366; p<0.001) between temperatures recorded by the two techniques. ROC curve analysis for temperatures recorded by infrared thermometer revealed an area under curve of 0.725 at a threshold of 98.6°F and 0.746 at a threshold of 100.4°F defined by mercury thermometer. Infrared thermometer had sensitivity, specificity, positive predictive value and negative predictive value of 13.61% and 9.38%, 97.95% and 99.80%, 71.43% and 75.00%, and 75.10% and 95.57% for thresholds of 98.6°F and 100.4°F respectively. Conclusion: Infrared thermometer underestimates temperatures recorded by mercury thermometer. Limits of agreement are too broad, indicating inconsistency in measurements. A significantly lower threshold is required to improve the sensitivity of Infrared thermometer in picking up fever.