Table 6.
Probability of ever using contraceptives methods, according to the World Health Organization’s tiered effectiveness, among female participants in the U.S.-based Nurses’ Healthy Study 2 and 31 by sexual orientation group.
| Risk Ratio2 (95%CI) | |||||
|---|---|---|---|---|---|
| Total N=118,462 | Heterosexual (NHS2) or Completely Heterosexual with no same-sex partners (NHS3) | Completely Heterosexual with same-sex partners | Mostly Heterosexual | Bisexual | Lesbian |
| NHS2 (n=99,850) | (n=98,509, 98.7%) | (n=415, <1%) | (n=926, 0.9%) | ||
| Contraceptive Method3 | |||||
| Tier 1 | ref. | 0.74 (0.67, 0.82) | 0.24 (0.20, 0.28) | ||
| Tier 2 | ref. | 0.97 (0.93, 1.01) | 0.77 (0.74, 0.81) | ||
| Tier 3 | ref. | 1.02 (0.92, 1.12) | 0.33 (0.28, 0.39) | ||
| Tier 4 | ref. | 1.09 (0.88, 1.34) | 0.37 (0.29, 0.48) | ||
| None | ref. | 1.00 (0.91, 1.10) | 1.00 (0.94, 1.07) | ||
| NHS3 (n=18,612) | (n=15,288, 82.1%) | (n=450, 2.4%) | (n=2,171, 11.7%) | (n=361, 1.9%) | (n=342, 1.8%) |
| Contraceptive Method3 | |||||
| Tier 1 | ref. | 1.17 (1.03, 1.32) | 1.26 (1.19, 1.33) | 1.30 (1.16, 1.46) | 0.19 (0.13, 0.29) |
| Tier 2 | ref. | 1.03 (1.00, 1.07) | 1.02 (1.00, 1.04) | 1.00 (0.96, 1.04) | 0.76 (0.70, 0.82) |
| Tier 3 | ref. | 0.99 (0.80, 1.23) | 1.17 (1.07, 1.28) | 1.06 (0.85, 1.33) | 0.18 (0.09, 0.34) |
| Tier 4 | ref. | 3.12 (1.26, 7.77) | 1.81 (1.00, 3.25) | 1.56 (0.38, 6.37) | 0.80 (0.11, 5.80) |
| None | ref. | 0.92 (0.79, 1.09) | 0.86 (0.79, 0.93) | 1.03 (0.87, 1.22) | 2.13 (1.89, 2.40) |
Nurses’ Health Study 2 (NHS2) participants were born 1947–1964 and Nurses’ Health Study 3 (NHS3) 1965–1995.
Adjusted for age and race. Multiple imputation was used during analyses for any missing covariate data. Models estimate the likelihood of using each contraceptive method vs all other methods (excluding none).
Tier 1=hormonal/non-hormonal intrauterine device (IUD), implant, tubal ligation, vasectomy; Tier 2=oral contraceptives, shots, ring, patch; Tier 3=male/female condom, diaphragm/cervical cap, natural family planning, rhythm; Tier 4=foam/jelly/spermicide/sponge, withdrawal. Frequencies add up to more than 100% due to participants being able to report more than one method.