Data for: Defining usual oral temperature ranges in outpatients using an unsupervised learning algorithm

Importance: Although oral temperature is commonly assessed in medical
examinations, the range of usual or “normal” temperature is poorly
defined. Objective: To determine normal oral temperature ranges by age,
sex, height, weight and time of day. Design: We applied a filtering
algorithm (LIMIT) to 10 years of outpatient temperature measurements.
LIMIT iteratively removed encounters with primary diagnoses
overrepresented in the tails of the temperature distribution, leaving only
those diagnoses unrelated to temperature. Mixed effects modeling was
applied to the remaining temperature measurements to identify independent
predictors of normal oral temperature and to generate individualized
normal temperature ranges. Setting: Single large medical care system,
divisions of Internal Medicine and Family Medicine. Participants: All
adult outpatient encounters that included temperature measurements, April
2008 - June 2017. Exposures: Primary diagnoses and medications,
age, sex, height, weight, time of day and month, abstracted from each
outpatient encounter. Main outcomes and measures: Normal temperature
ranges by age, sex, height, weight, and time of day. Results: From 618,306
encounters, 36% were removed by LIMIT because they included diagnoses or
medications that fell disproportionately in the tails of the temperature
distribution. The encounters removed due to overrepresentation in the
upper tail were primarily linked to infectious diseases (76.81% of all
removed encounters); type 2 diabetes mellitus was the only diagnosis
removed for over-representation in the lower tail (15.71% of all removed
encounters). Prior to running LIMIT, the mean overall oral temperature was
36.71°C (±0.43); following LIMIT, the mean temperature was 36.64°C
(±0.35). Using mixed effects modeling, age, sex, height, weight and time
of day accounted for 6.86% (overall) and up to 25.52% (per subject) of the
observed variability in temperature. Mean normal oral temperature did not
reach 37°C for any subgroup; the upper 99th percentile ranged from 36.8°C
(tall underweight old men in the morning) to 37.9°C (short obese young
women in the afternoon). Conclusion and relevance: Normal oral temperature
varies in a predictable manner based on sex, age, height, weight and time
of day, allowing individualized normal temperature ranges to be
established.