Figure 1.

PRISMA flow diagram of the literature screening and selection process. CENTRAL, Cochrane Central Register of Controlled Trials; CGD, cervicogenic dizziness; CiNii, Citation Information by NII; CNKI, China National Knowledge Infrastructure; DBpia, Database Periodical Information Academic; EMBASE, Excerpta Medica Database; KISS, Korean Studies Information Service System; KMbase, Korean Medical Database; MEDLINE, Medical Literature Analysis and Retrieval System Online; NDSL, National Digital Science Library; PRISMA, Preferred Reporting Items for Systematic reviews and Meta-Analyses; and RISS, Research Information Sharing Service.