The odds of thrombotic stroke in OC users (Case OC+) compared to non-users (Case OC-) is (2/5). The odds of thrombotic stroke in controls who are OC users (Control OC+) compared to non-users (Control OC-) is (44/55). The odds ratio (OR) for thrombotic stroke is calculated as: OR = (odds of exposure in cases) / (odds of exposure in controls) OR = (2/5) / (44/55) Now, let's calculate the OR: OR = (2/5) * (55/44) OR = (2*55) / (5*44) OR = 110 / 220 OR = 0.5 For the hemorrhagic stroke table, we have: Cases with OC use (Case OC+): 5 Cases without OC use (Case OC-): 13 Controls with OC use (Control OC+): 30 Controls without OC use (Control OC-): 107 The odds of hemorrhagic stroke in OC users (Case OC+) compared to non-users (Case OC-) is (5/13). The odds of hemorrhagic stroke in controls who are OC users (Control OC+) compared to non-users (Control OC-) is (30/107). The odds ratio (OR) for hemorrhagic stroke is calculated as: OR = (odds of exposure in cases) / (odds of exposure in controls) OR = (5/13) / (30/107) Now, let's calculate the OR: OR = (5/13) * (107/30) OR = (5*107) / (13*30) OR = 535 / 390 OR = 1.37 Interpretation of the findings: For thrombotic stroke, the OR