Performance of a non-contact infrared thermometer in healthy newborns

Objective To evaluate the performance of a non-contact infrared thermometer (NCIT) in comparison with digital axillary thermometer (DAT) and infrared tympanic thermometers (ITT) in a population of healthy at term and preterm newborns nursed in incubators. Setting 1 level III maternity hospital, and its intensive neonatal care unit. Participants 119 healthy at term newborns and 70 preterm newborns nursed in incubators were consecutively enrolled. Exclusion criteria were unstable/critical conditions, polymalformative congenital syndromes and severe congenital syndromes. Interventions Body temperature readings were prospectively collected. Each participant underwent bilateral axillary temperature measurement with DAT, bilateral tympanic measurement with ITT and mid-forehead temperature measurements using NCIT. Primary outcome measures Degree of agreement between methods was evaluated by the Bland and Altman method. Results 714 measurements in 119 healthy at term newborns and 420 measurements in 70 preterm newborns nursed in incubators were performed. Clinical reproducibility of NCIT was 0.0455 degrees C for infants in incubators and 0.0861 degrees C for infants outside an incubator. Bias was 0.029 degrees C for infants in incubators and <0.0001 degrees C for infants outside an incubator. Zero outliers were recorded. The mean difference between methods was good both for newborns at term (0.12 degrees C for NCIT vs DAT and 0.02 degrees C for NCIT vs ITT) and preterm newborns in incubators (0.10 degrees C for NCIT vs DAT and 0.14 degrees C for NCIT vs ITT). Limits of agreement were 0.99 to -0.75 and 0.78 to -0.75 in at term newborns and were particularly satisfactory in preterm newborns in incubators (95% CI: 0.48 to -0.27 and 0.68 to -0.40). Conclusions Our results with Bland and Altman analysis demonstrate that NCIT is a very promising tool, especially in preterm newborns nursed in incubators. Trial registration: The study was approved by the Careggi University Hospital Ethics Committee (07/2011).