Table 1.
Probability of failure within the first 3, 6 and 12 months of typical contraceptive use in the United States: weighted data, both unadjusted and adjusted for underreporting of abortion in the 1995 NSFG
| Method | Probability of failure, unadjusted
|
Probability of failure, adjusted
|
Unweighted na | ||||
|---|---|---|---|---|---|---|---|
| 3 months | 6 months | 12 months | 3 months | 6 months | 12 months | ||
| Injectable | 1.1 | 1.1 | 2.9 | 0.8 | 2.3 | 5.4 | 209 |
| Pill | 1.1 | 2.9 | 6.7 | 2.2 | 4.6 | 8.8 | 2127 |
| Diaphragm | 1.1 | 4.4 | 8.0 | 2.2 | 5.9 | 11.5 | 165 |
| Male condom | 2.4 | 5.3 | 8.6 | 5.4 | 10.2 | 17.8 | 2909 |
| Fertility-awareness | 4.6 | 14.4 | 19.6 | 5.5 | 16.2 | 22.6 | 249 |
| Spermicides | 4.9 | 9.2 | 16.4 | 8.5 | 16.8 | 28.2 | 272 |
| Withdrawal | 5.8 | 12.5 | 18.7 | 9.7 | 17.0 | 28.4 | 438 |
| All methods | 2.6 | 5.4 | 9.2 | 4.6 | 8.7 | 14.9 | 6839 |
a
Number of contraceptive-use segments.