Contraceptive method use among women and its association with age, relationship status and duration: findings from the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3).

BACKGROUND: One in six pregnancies in Britain are unplanned. An understanding of influences on contraceptive method choice is essential to provision compatible with users' lifestyles. This study describes contraceptive method use by age, and relationship status and duration, among women in Britain. METHODS: Data from women participating in the third British National Survey of Sexual Attitudes and Lifestyles were used to describe contraceptive use grouped as: unreliable method or none; barrier methods; oral/injectable hormonal methods; and long-acting reversible contraception. A total of 4456 women at risk of pregnancy were used to examine associations between contraception use, age, relationship type and duration. Age-stratified odds ratios for contraceptive use by relationship type and duration were estimated using binary logistic regression. RESULTS: Some 26.0% of 16-49-year-olds used hormonal contraception as their usual method. Use of hormonal and barrier methods was highest in the youngest age group and decreased with age; the reverse was true for use of unreliable methods or none. Barrier method use was higher in short-term relationships among younger participants; this was not seen among older respondents. Duration was more strongly associated with usual contraceptive method than relationship type; this pattern was more marked among younger participants. CONCLUSIONS: Asking about relationship status and duration may help providers support women's contraceptive use by considering their priorities and preferences at different life stages. Interactions between relationship characteristics, age and contraception are complex, and bear closer scrutiny both in research and in policy and practice.