First-year and 3-year Unadjusted Cumulative Kaplan–Meier Failure Rates: Subgroup Analyses by BMI, Age and Parity (Full Analysis Set).

BMI, body mass index; CI, confidence interval; LNG-IUS 8; levonorgestrel intrauterine system total content 13.5 mg (average approx. 8 μg/24 hours over the first year); LNG-IUS 13, levonorgestrel intrauterine system total content 19.5 mg (average approx. 13 μg/24 hours over the first year).First-year and 3-year Unadjusted Cumulative Kaplan–Meier Failure Rates: Subgroup Analyses by BMI, Age and Parity (Full Analysis Set).