Quasi experimental study of same-sex marriage laws & sexually transmitted infections

Objectives On June 26, 2015, the Supreme Court legalized same-sex marriages in the United States. This change has had some positive implications for the health of Lesbian, gay, bisexual, and transgender (LGBT) individuals and public health in general. Sexually transmitted infections (STIs) are common among LGBT individuals and legalization of same sex marriage effected the rate of emergency department (ED) visits for STIs. We examined the effect of same-sex marriage legalization on emergency department visits related to STIs among LGBT individuals. Study design Quasi-experimental difference-in-difference negative binomial design is used with state and time fixed-effects. We used data for 16 states from State Emergency Department Database and State Inpatient Database from January 2007–December 2015. People over 18 years of age visited the ED for STIs were included. Results At 5% significance level, number of STIs cases decreased by 6.1% (95% CI, 0.906–0.973; P = 0.001) after same-sex marriage legalization. When adjusting for sex, these cases decreased by 7.6% (95% CI, 0.885–0.966; P < 0.001) for females, and 4.7% (95% CI, 0.914–0.995; P = 0.027) for males. By age cohorts, 18–24 aged had 8.5% (95% CI, 0.875–0.957; P < 0.001) decrease, while older age cohorts was statistically insignificant. Conclusions Our results show that there is an association between legalization and decreased STIs cases in ED visits. Policy makers need to focus on encouraging a positive attitude towards LGBT community, as it leads to better quality of health for sexual minority groups and leads to positive externalities for general community.

本研究关注美国2015年同性婚姻合法化对LGBT群体性传播感染（STIs）相关急诊就诊率的影响，旨在探讨这一政策变革如何影响LGBT个体的健康状况及公共卫生领域，特别是同性婚姻合法化是否对LGBT群体的STIs急诊就诊率产生显著影响。

本研究采用准实验设计，比较同性婚姻合法化州（处理组）与未合法化州（对照组）在政策实施前后的性传播感染（STIs）急诊就诊率变化，使用差异中的差异（DID）模型与负二项分布进行分析，控制州和时间固定效应。数据来源于美国医疗成本与利用项目（HCUP）的州急诊数据库（SEDD）和州住院数据库（SID），分析2007年至2015年16个州STIs相关的ICD-9和ICD-10编码病例数。研究通过设置即时政策变化和12个月滞后效应两种模型，探讨同性婚姻合法化对STIs急诊就诊率的短期与长期影响，并按性别和年龄（18-24、25-40、41-64、65+岁）对数据进行分组分析。为验证模型稳健性，研究还使用肺结核与高血压的急诊就诊率进行虚假分析，以确保其他疾病的就诊率不会因同性婚姻合法化而显著变化。所有数据分析均在Stata 12中完成，且研究符合伦理审查豁免标准。

本研究通过分析同性婚姻合法化与LGBT群体性传播感染（STIs）急诊就诊率之间的关系，探讨政策对性少数群体健康状况的影响。研究采用准实验设计，比较同性婚姻合法化州与未合法化州在政策实施前后的STIs急诊就诊率变化，结合差异中的差异（DID）模型进行分析，控制州和时间固定效应。研究认为，同性婚姻合法化能促进社会对LGBT群体的接纳，改善其医疗可及性和健康结果，降低STIs发生率及相关医疗支出，从而为性少数群体创造更积极和支持性的社会环境。