Fig. 1.

Relative risk of cycle irregularity estimated from eight specifications of Eq. 1 separately testing differences by age, race/ethnicity, and six health conditions, (A) unweighted and unadjusted and (B) weighted and adjusted for app use frequency, contraceptive use, and pregnancy intentions. Race and health specifications: are also adjusted for age. The referent is the group with lowest risk (age: 35 y to 39 y; race/ethnicity: non-Hispanic Black persons); for health conditions: all without that condition. The 95% CIs are shown. Numeric relative risk values displayed in B are listed.