Forehead thermometers may be less accurate than oral thermometers in Black patients

Compared with oral temperature measurement, measurement with a temporal artery (forehead) thermometer was associated with lower odds of identifying fever in Black patients but not in White patients, a recent study found.

To assess racial differences in thermometry, researchers retrospectively evaluated the performance of temporal versus oral thermometry in detecting fever in adult patients admitted to four hospitals between 2014 and 2021. The inclusion criterion was suspected infection, defined as a combination of cultures and antibiotics within 24 hours of hospital presentation. Patients self-reported their race and ethnicity during hospital registration. For each patient, the study included the first pair of oral and temporal temperatures measured within one hour of each other within the first day of hospitalization; measurements after receipt of acetaminophen were excluded. The researchers examined the association between race, route of measurement, and fever (38 °C or greater, with repeat analyses under varying cutoffs), controlling for demographics, hospital, and comorbidities. They also conducted a sensitivity analysis on temperature measurements from the first hour of presentation. Results were published as a research letter on Sept. 6 by JAMA.

Overall, 2,031 Black patients and 2,344 White patients with paired temporal and oral measurements were included (patients who self-reported as Asian, Hispanic, or other were not included due to small sample sizes). Temporal temperature was lower than oral temperature in Black patients (36.98 °C vs. 37.05 °C; difference, −0.07 °C [95% CI, −0.10 to −0.04 °C]; P<0.001) but not in White patients (36.97 °C vs. 36.95 °C; difference, 0.02 °C [95% CI, −0.01 °C to 0.05 °C]; P=0.18), irrespective of which was measured first. The prevalence of fever with temporal and oral thermometry was 10.1% and 13.2% in Black patients and 10.8% and 10.2% in White patients, respectively. Compared with oral measurement, temporal measurement was associated with a significantly lower likelihood of identifying fever in Black patients (odds ratio [OR], 0.74 [95% CI, 0.61 to 0.90]; P=0.002) but not in White patients (OR, 1.07 [95% CI, 0.89 to 1.29]; P=0.47). The association was significant in Black patients at multiple fever cutoffs (38.0 °C, 38.3 °C, and 38.5 °C). In the sensitivity analysis of patients with paired measurements within the first hour of presentation, fever prevalence was 23.4% with temporal and 35.8% with oral measurement in 265 Black patients and 27.8% and 26.0%, respectively, in 281 White patients. Temporal measurement had a lower likelihood of finding fever in Black patients (OR, 0.54; [95% CI, 0.37 to 0.79]; P=0.002) but not in White patients (OR, 0.91 [95% CI, 0.62 to 1.34; P=0.62).

Limitations of the study include its retrospective design, inadequate power to evaluate differences in Asian and Hispanic patients, and potential selection bias of patients with paired measurements, the authors noted.

The findings suggest that the discrepancy in oral and temporal temperatures, combined with commonly used fever cutoffs, may cause fever to be undetected in many Black patients, they said. “The racial difference found may stem from the medical device or from systemic mishandling of the device (eg, not scanning the forehead sufficiently),” the authors wrote. “Differences in detection of fever could lead to delays in antibiotics and medical care for Black patients.”