Measuring contraceptive use patterns among teenage and adult women

Context: Measures of contraceptive use at one point in time do not account for ifs changing nature. A measure that addresses the pattern of method use over time may better predict the cumulative risk of unintended pregnancy. Methods: Women at risk of unintended pregnancy were selected from the 1995 National Survey of Family Growth, and their contraceptive use patterns were compared across age-groups. Survival analysis was used to validate women's long-term use pattern as an indicator of pregnancy risk, and multivariate regression analyses were used to explore potential covariates of current pa tterns of contraceptive use. Results: More than two-thirds of women aged 15-19 report long-term uninterr upted contraceptive use, but they are more likely to report sporadic use an d less likely to report uninterrupted use of a very effective method than a re women aged 25-34. Compared with women aged 25-34, women aged 20-24 have higher rates of sporadic use and lower rates of effective uninterrupted use . Among teenagers, nonusers are 12 times as likely as uninterrupted effecti ve users to experience an unintended pregnancy within 12 months at risk. Wo men in less stable relationships, those having more infrequent intercourse and women who have recently experienced nonvoluntary intercourse for the fi rst time are more likely than others to have a high-risk contraceptive patt ern. Women aged 17 and younger whose current partner is more than three yea rs older are significantly less likely to practice contraception than are t heir peers whose partner is closer in age. Conclusions: Long-term contraceptive use pattern is a valid predictor of un intended pregnancy risk. Policies aimed at reducing unintended pregnancies should target women who do not practice contraception and those who are spo radic users. Women in unstable relationships, those having infrequent sex a nd women who experience sexual coercion need access to methods, such as eme rgency contraception, that can be used sporadically or after unprotected in tercourse.