Table 2.
Classification of data analytics for wearable-generated temperature data.
| Types of analytics and description of the included studies | Temperature features | Analysis techniques | |||
| Descriptive analytics (n=19) | |||||
|
|
Compared differences in temperatures recorded across monitoring methods, patient cohorts, or anatomical sites [43,44,47] | Mean, SD, median, and maximum | Student t test and ANOVA | ||
|
|
Counted the numbers and frequencies of febrile events and compared the time difference between fever episodes detected by continuous and intermittent monitoring [17,38,39,42,47,48,50,52,58,61] | Timing of fever | Student t test | ||
|
|
Developed a heuristic scoring system to quantify the clinical relevance of fever detection, incorporating fever duration (short spike <60 minutes; prolonged episode ≥60 minutes) and clinical actions triggered [53] | Thresholds and fever duration | Descriptive comparison | ||
|
|
Hourly points from the continuous temperature data were used to simulate 1 to 24 intermittent daily measurements to identify the optimal timing and frequency achieving the highest fever detection rate [60] | Counts and frequencies | Brute-force strategy | ||
|
|
Compared the performance of fixed, individualized (baseline mean + 2SD), and combined thresholds for axillary temperature in detecting cytokine release syndrome [59] | Thresholds | Grid search | ||
|
|
Detected abnormal values or temperature deviations from preset thresholds to trigger alerts [17,61] | Thresholds | Described the counts and frequencies | ||
|
|
Visualized patterns of temperature, such as rising trends or fluctuations in temperature curves [41,46,51] | Visual patterns | Line plots | ||
|
|
Described the disappearance of the circadian rhythm of skin temperature in patients with critical illness, in comparison with recovered patients [49] | Circadian rhythmicity | Cosinor models | ||
| Diagnostic analytics (n=6) | |||||
|
|
Classified fevers of infectious or non-infectious causes using temperature trajectory patterns within 4 hours around fever start time [37] | Trajectory patterns | Dynamic time warping and k-means clustering | ||
|
|
Quantified fever intensity and evaluated its association with epidural analgesia duration and dosage to identify risk factors for fever [62] | Area under time-temperature curve | Logistic regression and ROCa curve analysis | ||
|
|
Examined the correlation between skin temperature and oral/ear canal temperature and identified a diagnostic cut-off value of skin temperature for detecting fever or infections [44,48,57] | Correlations | ROC curve analysis | ||
|
|
Analyzed the correlation between standard deviation and peak temperature to reveal an increased temperature variability before and after the spike [39] | Correlations | Pearson correlation and linear regression | ||
| Predictive analytics (n=9) | |||||
|
|
Predicted SCCb by inputting temperature data into a deep neural network to calculate an SCC score reflecting dissimilarity from normal patterns [45] | Cosine similarity | Deep neural network | ||
|
|
Used aggregated temperature features (median, variance, coefficient of variation) as inputs for pulmonary infection prediction models [56] | Median, variance, coefficient of variation | XGBoostc | ||
|
|
Extracted residual deviations of temperature from the patient's individual circadian rhythm pattern as early signs of febrile adverse events [6] | Circadian residuals | Circadian modeling and genetic algorithm | ||
|
|
Used continuous temperature data as inputs for machine learning models to predict the risk of advanced sepsis [54], cytokine release syndrome [59], or COVID-19 deterioration within the next 24 hours [63] | Mean, SD, extreme value, and percentage of time spent over thresholds | Machine learning models | ||
|
|
Used skin temperature features (eg, mean and maximum) within various time windows before fever onset as early predictive signals for impending fever episodes [40,55,57] | Correlations | Logistic regression and generalized estimating equation | ||
aROC: receiver operating characteristic.
bSCC: serious clinical complications.
cXGBoost: extreme gradient boosting.