Table 1.

Characteristics of the included studies.

Comparisons groups and studies		Learning modalities compared	Number and types of participants	Field of study	Outcomes
DPBLa vs traditional PBLb
	Alverson et al 2008 [44], RCTc, United States	VRd PBL vs traditional PBL	36 medical students (year unspecified)	Traumatic head injury	Knowledge
	Bowdish et al 2003 [22], RCT, United States	Online PBL vs traditional PBL	150 medical students (first year)	Human physiology	Knowledge
	Dennis 2003 [39], RCT, United States	Online PBL vs traditional PBL	34 medical students (second year)	Pregnancy-associated urinary incontinence	Knowledge
	Kong et al 2009 [21], RCT, China	Online PBL vs traditional PBL	90 medical students (year unspecified)	Ophthalmology	Knowledge
	Li et al 2013 [31], RCT, China	Offline PBL vs traditional PBL	120 medical students (fourth year)	Dermatology	Knowledge, Skills
	Moeller et al 2010 [43], RCT, Germany	Online PBL vs traditional PBL	237 medical students (year unspecified)	Multidisciplinary	Knowledge, Skills
	Sobocan et al 2017 [42], RCT, Slovenia	VPe-based PBL vs traditional PBL	34 medical students (third year)	Internal medicine	Knowledge
	Taradi et al 2005 [40], RCT, Croatia	Online PBL vs traditional PBL	121 medical students (second year)	Biochemistry (acid-base physiology)	Knowledge
DPBL vs traditional learning
	Kong et al 2009 [21], RCT, China	Online PBL vs traditional learning (lecture)	90 medical students (year unspecified)	Ophthalmology	Knowledge
	Li et al 2013 [31], RCT, China	Offline PBL vs traditional learning (lecture)	120 medical students (fourth year)	Dermatology	Knowledge
	Schutte et al 1997 [41], RCT, The Netherlands	VR PBL vs traditional learning (textbook)	68 medical students (first year)	Genetics (global structure of DNA)	Knowledge

^aDPBL: digital problem-based learning.

^bPBL: problem-based learning.

^cRCT: randomized controlled trial.

^dVR: virtual reality.

^eVP: virtual patient.