Table 2.

PROSPERO protocols with a single risk of bias tool listed

Study designs to be included in systematic review
RCT only N = 156		RCT and NRS N = 163
Tool	N(%)	Tool	N (%)
Cochrane RoB Tool [5]	133 (85.2)	Cochrane RoB Tool [5]	58 (35.6)
PEDro Scale [17]	9 (5.8)	Newcastle-Ottawa Scale [18]	20 (12.3)
Jadad Scale [19]	4 (2.6)	Downs and Black [16]	14 (8.6)
Cochrane RoB 2 Tool [20]	3 (1.9)	ROBINS-I [21]	7 (4.3)
Tool listed < 2 times	7 (4.5)	GRADE approach* [22]	6 (3.7)
		Mixed Methods Assessment Tool [23]	6 (3.7)
		Cochrane Handbook* [24]	5 (3.1)
		PEDro Scale [17]	5 (3.1)
		Jadad Scale [19]	4 (2.5)
		McMaster Critical Review Forum [25]	4 (2.5)
		EPHPP [26]	3 (1.8)
		MINORS [27]	3 (1.8)
		Oxford CEBM Levels of Evidence [28]	3 (1.8)
		Quality Criteria Checklist: Primary Research [29]	3 (1.8)
		NHLBI Pre-Post Quality Appraisal Tool [30]	2 (1.2)
		QUADAS-2 [31]	2 (1.2)
		Tool listed < 2 times	18 (11.0)

Note: Tools listed only once were excluded. Unless “2” or “2.0” was specifically stated, it was assumed that the original version of the Cochrane RoB Tool was being referenced

EPHPP = Effective Public Health Practice Project tool, MINORS = Methodological Index for Non-Randomized Studies, NHLBI = National Heart, Lung, and Blood Institute, NRS = non-randomized study; Oxford CEBM = Oxford Centre for Evidence-based Medicine Levels of Evidence, PEDro = Physiotherapy Evidence Database, QUADAS = Quality Assessment of Diagnostic Accuracy Studies, RCT = Randomized controlled trial; RoB = Risk of bias; ROBINS-I = Risk Of Bias In Non-randomized Studies - of Interventions

⁺These are not RoB tools, but were identified as such by protocol authors