A big data analysis of fever threshold and vital sign characteristics using tympanic temperature in hospitalized patients

Abstract

This study aimed to analyze vital sign characteristics of adult patients admitted at the Tertiary Hospital, and to define fever threshold and average body temperature by examining the tympanic temperatures of all patients. Retrospective medical data were extracted from 9195 patients aged > 21 years admitted to a tertiary hospital for elective surgeries between 2016 and 2020. Data regarding the patients' vital signs during their hospital stay, including tympanic body temperature, heart rate, and respiratory rate, were analyzed according to age, sex, and circadian rhythm. A normal-distribution graph was obtained when all the body temperature results were aligned. The average body temperature measured was 36.91 ± 0.45 °C (average ± standard deviation), indicating a potential fever threshold of 37.81 °C. When the participants were divided into age groups, the average temperature, heart rate, and respiratory rate exhibited parabolic trends. Patients in their 60s exhibited the lowest average temperature (36.88 °C), whereas those in their 50s had the lowest average heart rate (75.82/min) and lowest respiratory rate (19.08/min). Heart rate and respiratory rate tended to increase in elderly people older than 81 years. The average body temperature was greater in women than in men (36.94 ± 0.42 °C vs. 36.89 ± 0.47 °C), while the average heart (75.53 ± 10.04/min vs. 77.31 ± 11.52/min) and respiratory rates (19.13 ± 1.39/min vs. 19.29 ± 2.24/min) were lower in women than in men respectively. According to the time of measurement, the average temperature and heart rate appeared to follow a sinusoidal pattern, suggesting that the circadian rhythm was highest at 1 a.m. and lowest at 8 a.m. Tympanic temperature is a convenient measurement method preferred in hospital settings because it is noninvasive and easier to measure compared to other body parts. To develop an improved device and measurement method in the future, it is necessary to analyze tympanic temperature big data and compare it with past vital sign data or biometric information from other body parts.

Keywords: Body temperature; Circadian rhythm; Fever; Heart Rate; Respiratory rate.

Fig. 1

Study design and protocol used in this study. Datasets (n = 149,254) including demographic data and vital sign information from 9195 patients were included in the study.

Fig. 2

Body temperature of admitted patients. The average body temperature, which is indicated by the green line, was 36.91 °C with a standard deviation of 0.45. The blue line indicates the upper limit of 95% confidence interval (CI) at 37.81 °C (fever threshold).

Fig. 3

Average temperature, heart rate, and respiratory rate of admitted patients according to age group. (A) The average temperature (°C), heart rate (beats/min), and respiratory rate (/min) in different age groups. (B) The average temperature demonstrated a parabolic trend, with body temperature being lowest in those aged between 61 and 70 years. (C) The average heart rate was lowest in those aged between 51 and 60 years, and a tendency for the heart rate to increase was observed in those either younger or older than their 50s. (D) The graph depicting the average respiratory rate demonstrates a parabolic shape with breathing rates being lowest in those aged between 51 and 60 years. Overall, vital signs were generally lowest in those aged between 51 and 70 years.

Fig. 4

Average temperature, heart rate, and respiratory rate of admitted patients according to sex. (A) The average temperature (°C), heart rate (beats/min), and respiratory rate (/min) by sex. (B) The average body temperature was significantly greater in women than in men. (C) The average heart rate was significantly lower in women than in men. (D) The respiratory rate was significantly lower in women than in men. **Statistically significant.

Fig. 5

Average temperature, heart rate, and respiratory rate of admitted patients according to the time of measurement. (A) The measured biosignals were divided into hourly intervals, allowing for analysis of the data across a 24-h period. the circadian rhythm was highest at 1 a.m. and lowest at 8 a.m. (B) Body temperature increases during the day and decreases during the night while sleeping; in particular, at 8 a.m., the body temperature typically drops. (C) Heart rate shows a circadian rhythm similar to body temperature. In particular, the heart rate drops most at 8 a.m. (D) The respiratory rate does not show a specific circadian rhythm and is a constant pattern throughout the day.