Table 2.

Results from studies that used descriptive models with time-dependent output.

Method and authors			Domain		Independent variables		Dependent variable
Classical time series
	Chen et al [69]	Health care (patient data)		HRa, resting HR		Heartbeat
	Kazmi et al [33]	Physiology		HR, HRVb, time		HR
	Zakeri et al [80]	Physical activity		HR, energy expenditure, accelerometer, age		Energy expenditure
	Peng et al [70]	Medical		HR, heartbeat, time		HR
Mixed regression
	Gee et al [75]	Biomedical		HR, heartbeat, respiration, time		HR
	Bonomi et al [81]	Physical activity		HR, energy expenditure, photoplethysmography, accelerometer		HR
	Xu et al [82]	Physical activity		HR, energy expenditure, different training paradigms, age, height, weight		Energy expenditure

^aHR: heart rate.

^bHRV: heart rate variability.