Rose Sally B, Garrett Susan M, Stanley James, Pullon Susan R H
Department of Primary Health Care and General Practice, University of Otago, Wellington, New Zealand.
Biostatistical Group, University of Otago, Wellington, New Zealand.
Aust N Z J Obstet Gynaecol. 2017 Dec;57(6):665-675. doi: 10.1111/ajo.12685. Epub 2017 Aug 22.
Long-acting reversible contraception (LARC) effectively protects against pregnancy but provides no protection against sexually transmitted infections (STIs).
To compare rates of chlamydia testing and diagnosis for women initiating long-acting versus oral contraception.
Retrospective cohort study involving data collection for 6160 women initiating post-abortion contraception at a large New Zealand regional public hospital abortion clinic (2009-2012), with chlamydia testing data obtained from the local laboratory during two-year follow up. Negative binomial regression modelling examined the effect of contraceptive method on two outcome measures: chlamydia testing and chlamydia diagnosis (adjusting for potential covariates of age, ethnicity, past chlamydia infection, pregnancy history) in year one and two of follow up.
Two thousand seven hundred and twenty nine women (44%) received a LARC and 1764 (28.6%) were prescribed oral contraception. Adjusted testing rates differed by contraceptive method only in year one (P < 0.01): with higher rates among copper intrauterine device users (relative risk (RR) 1.2, 95% CI 1.06-1.35), and lower rates for implant users (RR 0.84, 95% CI 0.72-0.99) compared with oral contraceptive users (reference group). No significant differences were observed in chlamydia diagnosis rates by contraceptive method (P > 0.05). Younger age, past chlamydia infection, Maori and Pacific ethnicity were associated with higher rates of chlamydia diagnosis (P < 0.01).
Known STI-related risk factors (age, ethnicity, past infection) but not contraceptive method were independently related to rates of subsequent chlamydia diagnosis. This suggests that increased LARC uptake would not occur at the expense of chlamydia control. Regular screening and risk reduction advice (including condom use) are important chlamydia control measures for at-risk groups.
长效可逆避孕法（LARC）能有效预防怀孕，但无法预防性传播感染（STIs）。
比较开始使用长效避孕法与口服避孕药的女性衣原体检测和诊断率。
一项回顾性队列研究，收集了新西兰一家大型地区公立医院堕胎诊所6160名开始堕胎后避孕的女性的数据（2009 - 2012年），衣原体检测数据来自两年随访期间的当地实验室。负二项回归模型研究了避孕方法对两个结局指标的影响：随访第一年和第二年的衣原体检测和衣原体诊断（对年龄、种族、既往衣原体感染、妊娠史等潜在协变量进行调整）。
2729名女性（44%）采用了长效可逆避孕法，1764名（28.6%）被开了口服避孕药。仅在第一年，调整后的检测率因避孕方法而异（P < 0.01）：与口服避孕药使用者（参照组）相比，使用铜宫内节育器的女性检测率更高（相对风险（RR）1.2，95%可信区间1.06 - 1.35），而使用植入式避孕器的女性检测率较低（RR 0.84，95%可信区间0.72 - 0.99）。按避孕方法划分的衣原体诊断率未观察到显著差异（P > 0.05）。年龄较小、既往衣原体感染、毛利族和太平洋岛民种族与衣原体诊断率较高相关（P < 0.01）。
已知的性传播感染相关风险因素（年龄、种族、既往感染）而非避孕方法与后续衣原体诊断率独立相关。这表明增加长效可逆避孕法的使用不会以衣原体控制为代价。定期筛查和降低风险建议（包括使用避孕套）是高危人群重要的衣原体控制措施。
