Table 2.

Machine learning algorithms used in the reviewed studies (N=20).

Algorithm	Reference	Studies, n (%)
KNNa	Totty and Wade [46] Guan et al [48]	2 (10)
NBCb	Syed et al [45] Guan et al [48]	2 (10)
SVMc	Li et al [39] Guan et al [48]	2 (10)
ANNd	Gorjani et al [35]	1 (5)
LRe	Gorjani et al [35]	1 (5)
CNNf	Costa et al [40]	1 (5)
RNNg	Costa et al [40]	1 (5)
GM-HMMh	Guan et al [48]	1 (5)
HMMi	Helal et al [3]	1 (5)
Not reported	Demiris et al [51]	1 (5)
N/Aj	Brauner and Ziefle [32] Chung et al [33] Görer et al [34] Fung et al [37] Biagetti et al [38] Li et al [39] Paay et al [41] Rahman and Hossain [42] Sahu et al [43] Schmied et al [44] Cahill et al [47] Naranjo-Hernández [49]	12 (60)

^aKNN: k-nearest neighbor.

^bNBC: naïve Bayes classifier.

^cSVM: support vector machine.

^dANN: artificial neural network.

^eLR: logistic regression.

^fCNN: convolutional neural network.

^gRNN: recurrent neural network.

^hGM-HMM: Gaussian mixture hidden Markov model.

ⁱHMM: hidden Markov model.

^jN/A: not applicable.