Table 1. Comparison between imbalanced data versus imbalance mitigation strategies.

Studies	Participant distribution	Techniques	Conclusion
Moon et al [29]	524 patients with PDa and 43 patients with essential tremor	SMOTEb	F1-score improved
Veeraragavan et al [30]	93 patients with idiopathic PD and 73 controls; 10 patients with H&Yc 3; 28 patients with H&Y 2.5; and 55 patients with H&Y 2	SMOTE	Test accuracy improved
Falchetti et al [31]	388 patients with idiopathic PD and 323 controls	Oversampling Undersampling Combination of oversampling and undersampling	Without any sampling, the combination of oversampling and undersampling methods is comparable
Jeancolas et al [32]	115 patients with PD and 152 controls	Data augmentation	Performed better for free speech task No consistent improvement in the sentence repetition task

^aPD: Parkinson disease.

^bSMOTE: synthetic minority oversampling technique.

^cH&Y: Hoehn and Yahr.