Abstract：
BACKGROUND: Pregnancy is the second most common cause of limited duty days among active duty service members in the U.S. Military. Pregnancy accounts for 10% of all days on restricted duty, despite impacting a minority of active duty service members. One out of five service women will experience an unintended pregnancy every year despite the availability of no-cost contraception and reproductive healthcare. Young, single, junior enlisted service women experience the highest rate of unintentional pregnancy. Previous studies have demonstrated service branch-based variability in selection, initiation, and continuation of specific contraceptive methods related to service branch culture and access to contraception during basic training. It is unclear if these differences impact overall contraception use or fertility rates among junior enlisted service women in their first term of enlistment. This study examines rates of contraceptive selection, initiation, continuation, and efficacy among junior enlisted service women in their first 4-year enlistment period, and the service branch specific variability in these outcomes.
METHODS: This study is a secondary analysis of Military Healthcare Data Repository records from women who began basic training between 2012 and 2020 and remained on active duty for at least 12 months. We used Kaplan-Meier analyses to examine the effect of age and military branch on contraceptive continuation and efficacy. We used binomial regression for interval censored data, to assess the association of service branch with rates of contraceptive initiation, contraception use, births, and childbirth-related duty restrictions.
RESULTS: We identified 147,594 women who began basic training between 2012 and 2020. The mean age of these women at the beginning of basic training was 20.4 ± 3.1 years. Women in the marines and navy had higher contraceptive initiation rates than women in the army or air force. Among women initiating a contraceptive pill, patch, or ring (short-acting reversible contraception), 58.3% were still using some form of hormonal contraception 3 months later. Among women initiating depot-medroxyprogesterone (DMPA), 38.8% were still using any form of hormonal contraception 14 weeks later. Long-acting reversible contraceptive methods, such as intrauterine or subdermal contraceptives, had higher continuation rates and less service-based variability in continuation and failure rates than short-acting reversible contraception or depot-medroxyprogesterone. The proportion of days on any form of prescription contraception during the first 4 years on active duty varied from 23.3% in the army to 38.6% in the navy. The birth rate varied from 34.8 births/1,000 woman-years in the air force up to 62.7 births/1,000 woman-years in the army. Compared with women in the air force, women in the army experienced 2,191 additional days of postpartum leave and 13,908 days on deployment restrictions per 1,000 woman-years.
CONCLUSIONS: Service branch specific variability in contraceptive use is associated with differences in days of pregnancy-related duty restrictions during first 4 years on active duty among junior enlisted females. Robust implementation of best practices in contraceptive care across the military health system to improve contraceptive initiation and continuation appears to offer an opportunity to improve military readiness and promote the health and well-being of active duty service women, particularly in the army.
METHODS: This study is a secondary analysis of Military Healthcare Data Repository records from women who began basic training between 2012 and 2020 and remained on active duty for at least 12 months. We used Kaplan-Meier analyses to examine the effect of age and military branch on contraceptive continuation and efficacy. We used binomial regression for interval censored data, to assess the association of service branch with rates of contraceptive initiation, contraception use, births, and childbirth-related duty restrictions.
RESULTS: We identified 147,594 women who began basic training between 2012 and 2020. The mean age of these women at the beginning of basic training was 20.4 ± 3.1 years. Women in the marines and navy had higher contraceptive initiation rates than women in the army or air force. Among women initiating a contraceptive pill, patch, or ring (short-acting reversible contraception), 58.3% were still using some form of hormonal contraception 3 months later. Among women initiating depot-medroxyprogesterone (DMPA), 38.8% were still using any form of hormonal contraception 14 weeks later. Long-acting reversible contraceptive methods, such as intrauterine or subdermal contraceptives, had higher continuation rates and less service-based variability in continuation and failure rates than short-acting reversible contraception or depot-medroxyprogesterone. The proportion of days on any form of prescription contraception during the first 4 years on active duty varied from 23.3% in the army to 38.6% in the navy. The birth rate varied from 34.8 births/1,000 woman-years in the air force up to 62.7 births/1,000 woman-years in the army. Compared with women in the air force, women in the army experienced 2,191 additional days of postpartum leave and 13,908 days on deployment restrictions per 1,000 woman-years.
CONCLUSIONS: Service branch specific variability in contraceptive use is associated with differences in days of pregnancy-related duty restrictions during first 4 years on active duty among junior enlisted females. Robust implementation of best practices in contraceptive care across the military health system to improve contraceptive initiation and continuation appears to offer an opportunity to improve military readiness and promote the health and well-being of active duty service women, particularly in the army.
摘要：
背景：怀孕是美国现役军人的第二大常见原因。怀孕占所有限制值班天数的10%，尽管影响了少数现役军人。尽管有免费的避孕和生殖保健服务，但五分之一的在职妇女每年都会意外怀孕。年轻,单身,初级服役妇女意外怀孕率最高。以前的研究已经证明了基于服务分支的选择可变性，initiation,并在基本培训期间继续使用与服务部门文化和获得避孕药具有关的特定避孕方法。目前尚不清楚这些差异是否会影响初级服役妇女在第一任期内的整体避孕使用率或生育率。这项研究调查了避孕药的选择率，initiation,延续,在第一个4年入伍期的初级服役女性中，以及服务部门在这些结果中的特定可变性。
方法：这项研究是对2012年至2020年期间开始接受基础培训并至少12个月现役的女性的军事医疗数据存储记录的二次分析。我们使用Kaplan-Meier分析来检查年龄和军事部门对避孕延续和疗效的影响。我们对间隔删失数据使用二项回归，评估服务部门与避孕药具启动率的关联，避孕使用,出生,和分娩相关的职责限制。
结果：我们确定了在2012年至2020年期间开始接受基础培训的147,594名女性。这些妇女在基础培训开始时的平均年龄为20.4±3.1岁。海军陆战队和海军中的女性避孕率高于陆军或空军中的女性。在服用避孕药的女性中，补丁,或环（短效可逆避孕），58.3％的人在3个月后仍使用某种形式的激素避孕。在开始服用甲羟孕酮(DMPA)的女性中，38.8%的人在14周后仍在使用任何形式的激素避孕。长效可逆避孕方法，如子宫内或皮下避孕药，与短效可逆避孕或长效甲羟孕酮相比，延续率更高，基于服务的连续性和失败率的变异性更小。在现役的前4年中，任何形式的处方避孕天数的比例从陆军的23.3％到海军的38.6％不等。出生率从空军的34.8个婴儿/1,000个妇女年到军队的62.7个婴儿/1,000个妇女年不等。与空军女性相比，军队中的妇女每1000个妇女年增加了2,191天的产后假期和13,908天的部署限制。
结论：服务部门使用避孕药具的特定差异与初级入伍女性在前4年中与怀孕相关的职责限制天数的差异有关。在整个军事卫生系统中大力实施避孕护理最佳做法，以改善避孕方法的开始和延续，似乎为改善军事准备和促进现役军人的健康和福祉提供了机会，尤其是在军队中。
方法：这项研究是对2012年至2020年期间开始接受基础培训并至少12个月现役的女性的军事医疗数据存储记录的二次分析。我们使用Kaplan-Meier分析来检查年龄和军事部门对避孕延续和疗效的影响。我们对间隔删失数据使用二项回归，评估服务部门与避孕药具启动率的关联，避孕使用,出生,和分娩相关的职责限制。
结果：我们确定了在2012年至2020年期间开始接受基础培训的147,594名女性。这些妇女在基础培训开始时的平均年龄为20.4±3.1岁。海军陆战队和海军中的女性避孕率高于陆军或空军中的女性。在服用避孕药的女性中，补丁,或环（短效可逆避孕），58.3％的人在3个月后仍使用某种形式的激素避孕。在开始服用甲羟孕酮(DMPA)的女性中，38.8%的人在14周后仍在使用任何形式的激素避孕。长效可逆避孕方法，如子宫内或皮下避孕药，与短效可逆避孕或长效甲羟孕酮相比，延续率更高，基于服务的连续性和失败率的变异性更小。在现役的前4年中，任何形式的处方避孕天数的比例从陆军的23.3％到海军的38.6％不等。出生率从空军的34.8个婴儿/1,000个妇女年到军队的62.7个婴儿/1,000个妇女年不等。与空军女性相比，军队中的妇女每1000个妇女年增加了2,191天的产后假期和13,908天的部署限制。
结论：服务部门使用避孕药具的特定差异与初级入伍女性在前4年中与怀孕相关的职责限制天数的差异有关。在整个军事卫生系统中大力实施避孕护理最佳做法，以改善避孕方法的开始和延续，似乎为改善军事准备和促进现役军人的健康和福祉提供了机会，尤其是在军队中。
