MS Speaks

Most people probably use oral thermometers if they want to record temperature (rectal ones for infants).  This article claims to have shown that peripheral thermometers (oral, axillary, etc.) aren't as good at detecting fever as central thermometers (e.g., rectal).

From NEJM Journal Watch, citing Annals of Internal Medicine (November 17, 2015):

How Reliable Are Peripheral Thermometers?

Jamaluddin Moloo, MD, MPH Reviewing Niven DJ et al., Ann Intern Med 2015 Nov 17; 163:768

In a meta-analysis, the sensitivity of peripheral thermometers for detecting fever was only 64%.

Accurate evaluation of body temperature is essential in many clinical scenarios. In this systematic review and meta-analysis, researchers examined data from 75 prospective studies in which the accuracy of peripheral thermometers (tympanic membrane, temporal, axillary, or oral) was compared with central thermometers (pulmonary artery catheter [the gold standard for temperature measurement], urinary bladder, esophageal, or rectal). Analysis involved nearly 8700 patients; 42 studies were in adults, 32 studies were in children, and 1 study was in both.

The pooled sensitivity and specificity for detecting fever by peripheral thermometers were 64% and 96%, respectively; in other words, when a peripheral thermometer detected fever, it was likely present, but peripheral thermometers frequently missed fever. Sensitivity was lowest for axillary thermometers (42%).

Comment

These findings might have been skewed by publication bias (negative studies often are not published) as well as by differences in the temperature thresholds used to define fever in the populations studied. Nevertheless, the findings indicate that peripheral thermometers have poor sensitivity for detecting fever — an issue of particular concern in patients with low-grade fever. In such situations, central measurement of body temperature might be necessary.

Editor Disclosures at Time of Publication:

Disclosures for Jamaluddin Moloo, MD, MPH at time of publication

Grant / Research support

Colorado Health Foundation

The article can be seen here.