Fig. 2From: Evolution of appraisal tool usage preferences in PROSPERO records: a study of non-Cochrane systematic reviewsThis panel represents tools included in protocols for SRs by condition or domain being studied and time-course changes. a Tools by condition or domain being studied. Points represent protocols and are colored according to the appraisal purpose of the toolkit: red for risk of bias tools, blue for reporting assessment tools, green for methodological quality tools, and black for multiple-purpose appraisal tools. Point size is proportional to the number of protocols in each category. b Tools by year of registration in PROSPEROBack to article page