Table 1.

Characteristics of included studies

First author, year, country	Participants*	Study design†	No. and duration of training sessions	Duration of intervention	Comparison(s)‡	Type of outcome(s) of interest	Outcome measures
Comparison: AEEs versus other educational interventions
Casebeer, 2003, USA	PP; n=181	RCT; post-test-only, 2 groups	Four sessions; 1 hour each	NR	NR	Knowledge	21-item multiple-choice questionnaire
						Skills
Cook, 2008, USA	R; n=122	RXT; post-test-only, 4 groups	Four sessions; 30 min each	126 days	NEE	Knowledge	69-item case-based multiple-choice questionnaire
Crowley, 2010, USA	PP; n=15	RCT; pretest–post-test, 2 groups	Four sessions; 4 hours each	138 days	P	Skills	Virtual slide test to examine diagnostic accuracy
de Ruijter, 2018, the Netherlands	NP; n=269	RCT; pretest–post-test, 2 groups	No fixed sessions	180 days	NEE	Knowledge	18-item true-false questionnaire (range 0–18)
						Behaviour	9-item self-reported questionnaire (range 0–9)
Hayes-Roth, 2010 USA	MS, NS; n=30	RCT; pretest–post-test–retention-test, 3 groups	NR; mean training time 2.36 hours	NR	NEE NI	Skills	6-item written skill probe (range −6–18)
Lee, 2017, USA	MS; n=1522	NRCT; pretest–post-test, 3 groups	Five sessions; NR	42 days	NEE	Knowledge	Unclear
						Skills	Multidimensional situation-based questions—Real Index (range 0%–100%)
						Behaviour	Unclear
Micheel, 2017, USA	PP, NP; n=751	NRCT; pretest–post-test–retention-test, 2 groups	NR	NR	NEE	Knowledge	10-item true-false questionnaire (range 0–10)
Morente, 2013, Spain	NS; n=73	RCT; pretest–post-test, 2 groups	One session; 4 hours	1 day	T	Knowledge	22-item multiple-choice questionnaire (range 0–22)
Munoz, 2010, Colombia	MS; n=40	NRCT; pretest–post-test, 2 groups	NR; mean training time 5.97 hours	NR	NEE	Knowledge	10-item multiple-choice questionnaire (range 0–10)
Romito, 2016, USA	R; n=24	NRCT; pretest–post-test–retention-test, 2 groups	One session; 30 min	1 day	NEE and T	Skills	22-item video clip-based test
Samulski, 2017, USA	MS, R, PP; n=36	RXT; pretest–post-test, 2 groups	Two sessions; 20 min to 14 hours	1 month	P	Knowledge	28-item multiple-choice questionnaire (range 0%–100%)
Thai, 2015, USA	HSC; n=87	RCT; pretest–post-test–retention-test, 3 groups	One session; 45 min	1 day	AEE NEE	Skills	14-item case-based test (range 0%–100%)
Van Es, 2015, Australia	R; n=43	RXT; post-test-only, 2 groups	Three sessions; NR	50 days	P	Knowledge	7-item to 21-item multiple-choice questionnaire (range 0%–100%)
Van Es, 2016, Australia	MS; n=46	RXT; post-test-only, 2 groups	Three sessions; 2 hours each	34 days	NEE	Knowledge	Multiple-choice questionnaire
Wong, 2015, Australia	MS; n=99	RXT; post-test-only, 2 groups	Two sessions; 1.5 hour each	14 days	NEE	Knowledge	8-item multiple-choice and interactive questions (range 0%–100%)
Wong, 2017, USA	MS; n=178	NRCT; pretest–post-test–retention-test, 3 groups	One session; NR	35 days	T AEE and T	Skills	Test to examine diagnostic accuracy
Woo, 2006, USA	MS; n=73	NRCT; pretest–post-test, 3 groups	One session; 2 hours	1 day	NEE NI	Knowledge	Short-response questionnaire
Comparison: adaptive e-learning vs adaptive e-learning (two AEEs with design variations)
Crowley, 2007, USA	R; n=21	RCT; pretest–post-test–retention-test, 2 groups	One session; 4.5 hours	1 day	AEE	Knowledge	51-item multiple-choice questionnaire (range 0%–100%)
El Saadawi, 2008, USA	R; n=20	RXT; pretest–post-test, 2 groups	Two sessions; 2 hours each	1 day	AEE	Skills	Virtual slide test to examine diagnostic accuracy
El Saadawi, 2010, USA	R; n=23	RXT; pretest–post-test, 2 groups	Two sessions; 2.25 hours each	2 days	AEE	Skills	Virtual slide test to examine diagnostic accuracy
Feyzi-Begnagh, 2014, USA	R; n=31	RCT; pretest–post-test, 2 groups	Two sessions; 2 hours and 3 hours	1 day	AEE	Knowledge	Unspecified test

*Participants: MS, medical students; NS, nursing students; R, residents (physicians in postgraduate training); PP, physicians in practice; NP, nurses in practice; HSC, health sciences students.

†Study design: RCT, randomised controlled trial; RXT, randomised cross-over trial; NRCT, non-randomised controlled trial.

‡Comparison: AEE, adaptive e-learning environment; NEE, non-adaptive e-learning environment; NI, no-intervention control group; T, traditional (group lecture); P, paper (handout, textbook or latent image cases).

NR, not reported.