Mercer Catherine H, Copas Andrew J, Sonnenberg Pam, Johnson Anne M, McManus Sally, Erens Bob, Cassell Jackie A
Centre for Sexual Health & HIV Research, Research Department of Infection & Population Health, University College London, Mortimer Market Centre, London WC1E 6JB, UK.
Int J Epidemiol. 2009 Feb;38(1):206-14. doi: 10.1093/ije/dyn216. Epub 2008 Nov 11.
Sexually transmitted infection (STI) risk is determined both by partner numbers and partnership characteristics. Studies describing only recent partnership(s) overestimate long-term partnerships and underestimate the contribution of casual partnerships to STI transmission in populations. We describe all heterosexual partnerships in the past year in terms of partnership type, age and geographical mixing and how these characteristics relate to condom use.
Probability sample survey of 11 161 men and women aged 16-44 resident in Britain, 1999-2001. Computer-assisted self-interviews asked respondents about partner numbers and detailed questions about their three most recent partnerships. We weight these data to represent partnerships for which detailed questions were not asked to present estimates for the population of partnerships.
Of 15 488 heterosexuals partnerships, 39.1% (95% CI 36.6-41.7%) of men's partnerships were 'not (yet) regular' vs 20.0% (95% CI 18.2-21.9%) of women's partnerships. While condoms were used at last sex in 37.1% (95% CI 35.0-39.3%) of men's and 28.8% (95% CI 27.1-30.6%) of women's partnerships, and for 55.3% (95% CI 52.6-58.0%) of first sex with new partners, these proportions declined with age. When partnerships involved an age difference of 5+ years [26.2% (95% CI 23.0-29.6%) of men's and 36.5% (95% CI 33.0-40.1%) of women's partnerships], condoms were less commonly used at first sex than when partners were closer in age [44.1% (95% CI 39.1-48.4%) vs 60.8% (95% CI 57.3-64.2%)]. Sex occurred within 24 h in 23.4% (95% CI 19.7-27.5%) of men's and 10.7% (95% CI 8.3-13.6%) of women's partnerships.
A substantial minority of partnerships in the population is casual. The proportion of partnerships not protected by condoms is high, especially for partnerships involving larger age differences and people in their 30s and 40s. Condom use with new partners needs to be promoted among all age-groups.
性传播感染（STI）风险由性伴侣数量和伴侣关系特征共同决定。仅描述近期伴侣关系的研究高估了长期伴侣关系，并低估了偶然伴侣关系在人群中对性传播感染传播的贡献。我们根据伴侣关系类型、年龄和地域混合情况描述了过去一年中所有异性伴侣关系，以及这些特征与避孕套使用之间的关系。
1999 - 2001年对居住在英国的11161名16 - 44岁男女进行概率抽样调查。通过计算机辅助自填式访谈询问受访者性伴侣数量，并就其最近的三段伴侣关系提出详细问题。我们对这些数据进行加权，以代表未被询问详细问题的伴侣关系，从而得出总体伴侣关系的估计值。
在15488段异性伴侣关系中，男性伴侣关系中有39.1%（95%置信区间36.6 - 41.7%）为“（尚未）固定”，而女性伴侣关系中这一比例为20.0%（95%置信区间18.2 - 21.9%）。在男性的37.1%（95%置信区间35.0 - 39.3%）和女性的28.8%（95%置信区间27.1 - 30.6%）的伴侣关系中，最后一次性行为时使用了避孕套；在与新伴侣的首次性行为中，这一比例为55.3%（95%置信区间52.6 - 58.0%），但这些比例随年龄增长而下降。当伴侣关系中年龄相差5岁及以上时（男性伴侣关系中的26.2%（95%置信区间23.0 - 29.6%）和女性伴侣关系中的36.5%（95%置信区间33.0 - 40.1%）），首次性行为时使用避孕套的情况比伴侣年龄相近时更少（分别为44.1%（95%置信区间39.1 - 48.4%）和60.8%（95%置信区间57.3 - 64.2%））。在男性的23.4%（95%置信区间19.7 - 27.5%）和女性的10.7%（95%置信区间(8.3 - 13.6%)）的伴侣关系中，性行为发生在24小时内。
人群中相当一部分伴侣关系是偶然的。未受避孕套保护的伴侣关系比例很高，尤其是涉及较大年龄差的伴侣关系以及30多岁和40多岁人群的伴侣关系。需要在所有年龄组中推广与新伴侣使用避孕套的行为。
