Table 3.

Features of AI-based techniques used for COVID-19.

Features		Studies (N=82), n
AIa branchesb
	Deep learning	60
	Machine learning	29
	Natural language processing	3
AI models/ algorithmsc
	Convolutional neural network	37
	Support vector machine	10
	Random forest	9
	Decision tree	9
	Logistic regression	9
	Recurrent neural network	8
	Artificial neural network (unspecified)	6
	Transfer learning	4
	Autoencoders	4
	Deep neural network	3
	K-nearest neighbors	3
	Least absolute shrinkage and selection operator	3
	Polynomial neural network	3
	Multilayer perceptron	2
	Advance deep Q-learning network	2
	AdaBoost	1
	Auto-regressive integrated moving average model	1
	Bayesian analysis	1
	Bidirectional encoder representations from transformers	1
	Continuous bag of words	1
	Eureqa modeling	1
	Genetic algorithm	1
	Generative adversarial network	1
	Generalized logistic growth model	1
	Holistic agent-based model	1
	Linear discriminant analysis	1
	Linear regression	1
	Language model	1
	Multi-task deep model	1
	Naive Bayes	1
	Porter stemming	1
	Reinforcement learning	1
	Skip-gram model	1
	Time series forecasting	1
	Universal-sentence-encoder-large	1
	Vector auto average	1
Platforms
	Computer	81
	Mobile	1

^aAI: artificial intelligence.

^bNumbers do not add up as AI techniques in some studies were based on more than one AI branch.

^cNumbers do not add up as several studies used more than one AI model or algorithm.