Table 54Strength of evidence domains for the effect of OC use on stroke

ComparisonNumber of Studies (Women and/or Person-Years)Domains Pertaining to SOESOE and Magnitude of Effect (95% CI)
Risk of BiasConsistencyDirectnessPrecision
Incidence of Ischemic/Undifferentiated Stroke
Current vs. noncurrent use/never9 (54,767 plus 310,564 person-years)MediumConsistentDirectPreciseHigh
2.15 (1.49 to 3.11)
Duration4 (51,038 plus 310,626 person-years)MediumConsistentDirectImpreciseInsufficient
NR (Insufficient evidence to support quantitative synthesis of findings)
Estrogen3 (9977)MediumConsistentDirectPreciseHigh
Low dose: 1.73 (1.29 to 2.32)

High dose: 4.10 (1.91 to 8.80)
Progestin3 (6994)MediumInconsistentDirectImpreciseInsufficient
NR (heterogeneity in evidence about specific progestin generation)
Incidence of Ischemic Stroke
Current vs. noncurrent use/never7 (49,803 plus 310,564 person-years)MediumConsistentDirectPreciseHigh
1.90 (1.24 to 2.91)
Incidence of Hemorrhagic Stroke
Current vs. noncurrent use/never4 (48,382)MediumInconsistentDirectImpreciseLow
No difference, 1.03 (0.71 to 1.49)
Mortality From Stroke
Current vs. noncurrent use/never3 (46,112 plus 3,091,673 person-years)MediumConsistentDirectImpreciseModerate
0.80 (0.59 to 1.08)

CI = confidence interval; SOE = strength of evidence

From: 4, Oral Contraceptives and Vascular Events

Cover of Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer
Oral Contraceptive Use for the Primary Prevention of Ovarian Cancer.
Evidence Reports/Technology Assessments, No. 212.
Havrilesky LJ, Gierisch JM, Moorman PG, et al.

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