Department of Population, Family and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Glob Health Sci Pract. 2022 Apr 29;10(2). doi: 10.9745/GHSP-D-21-00597. Print 2022 Apr 28.
Standard measures of contraceptive prevalence have known biases given that they do not reflect sexual activity and true exposure to the risk of an unintended pregnancy. In this study, we aim to understand the extent to which women protect themselves against unintended pregnancy, taking into account exposure to sex, by examining contraceptive use patterns by marital status and recent sexual activity.
Data come from population-based surveys of reproductive age women in 9 low-resource settings. We estimated contraceptive prevalence using (1) the standard current contraceptive use measure, (2) a new measure of contraceptive use at last sex, and (3) a comprehensive measure that combines current use and use at last sex. Analyses are stratified by site and examine patterns by marital status only, and by both marital status and sexual activity separately. We then examined method mix by each contraceptive measure.
Study findings reveal distinct patterns in contraceptive use in relation to marital status and sexual recency across sites. Overall, married women tended to report higher levels of current contraceptive use compared to use at last sex, whereas unmarried women reported higher levels of contraceptive use at last sex. When examining these measures by sexual activity and marital status, results indicate lower levels of contraceptive use among women who had not had sex in the month prior to the survey, for both married and unmarried women. The comprehensive measure of contraceptive use yielded the highest estimates, by design. Method mix varied consistently by contraceptive measure, with current use tending to capture more permanent and long-acting methods and use at last sex more likely to capture short-acting and coital-dependent methods.
These findings have important implications for how the family planning field evaluates unintended pregnancy risk and unmet need for contraception within low-resource settings, given different estimates yield discrepant estimates for who is "at risk."
由于标准避孕普及率的衡量方法不能反映性行为和真实的意外怀孕风险，因此存在已知的偏差。本研究旨在通过考察不同婚姻状况和近期性行为下的避孕使用模式，了解女性在多大程度上通过性行为来防止意外怀孕。
数据来自 9 个资源匮乏环境中育龄女性的基于人群的调查。我们使用（1）标准的当前避孕使用措施，（2）最近一次性行为时的避孕使用新措施，（3）综合当前使用和最近一次性行为使用的综合措施来估计避孕普及率。分析按地点分层，仅考察婚姻状况的模式，并分别考察婚姻状况和性行为的模式。然后，我们按每种避孕措施考察方法组合。
研究结果揭示了不同地点在婚姻状况和最近性行为与避孕使用之间的明显模式。总体而言，已婚女性倾向于报告比最近一次性行为时更高的当前避孕使用率，而未婚女性则报告最近一次性行为时更高的避孕使用率。当按性行为和婚姻状况考察这些措施时，结果表明在调查前一个月没有发生性行为的女性的避孕使用率较低，无论是已婚还是未婚女性。综合避孕使用措施因设计而产生了最高的估计值。按避孕措施，方法组合始终存在差异，当前使用更倾向于捕捉更持久和长效的方法，而最近一次性行为更可能捕捉短期和依赖性行为的方法。
这些发现对计划生育领域在资源匮乏环境中评估意外怀孕风险和未满足的避孕需求具有重要意义，因为不同的估计方法会对“处于风险之中”的人群产生不同的估计。
