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

Data files

Jul 17, 2023 version files 38.30 MB

Abstract

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.