Benign Paroxysmal Positional Vertigo and the Increased Risk of Ischemic Stroke: A Nested Case-Control Study Using a National Cohort Sample

Figure 1

Schematic illustration of the participant selection process used in this study. (a) From a total of 1,125,691 participants, 15,610 ischemic stroke participants were matched with 62,440 control I participants for age, group, sex, income group, residential location, and past medical history. (b) From a total of 1,125,691 participants, 4,923 hemorrhagic stroke participants were matched with 19,692 control II participants for age, group, sex, income group, residential location, and past medical history.

(a)

(b)