Meaning of the DID method.

Background Civil unrest is a collective term that includes limited political violence, sporadic violent collective action, or nonviolent and mildly violent collective action that causes dissatisfaction over political, economic, or social changes. It had deadly impacts on the lives of children and adolescents. It often results in difficulties for civilian to access basic services including healthcare. Objective Evaluate the effect of civil unrest on child healthcare provision evidenced by the proportion of children admitted with acute medical complications. Methods Institution-based retrospective comparative study of Difference in Difference with Propensity Score Matching (PSM-DID) was implemented. Setting and participants The study was conducted on children admitted to pediatric ward of Bahir Dar University Tibebe-Ghion specialized teaching hospital. Data were collected from medical records for the months of January 01, 2023 – July 31, 2023 (pre-civil unrest) and August 01, 2023 – February 29, 2024 (into the civil unrest), on a retrospective basis. 632 Participants (345 in the treatment and 247 in the control group) were selected randomly using Microsoft Excel based on their medical record number (MRN) from the HMIS registry with treatment assignment (rural residency or not). Results PSM was conducted on 7 covariates. In the unmatched sample, significant differences between groups were found for two of the 7 covariates. PSM successfully adjusted for bias in all covariates in the matched sample. The civil unrest has increased acute medical complications at presentation to our hospital for rural residents, with a DID value of 0.241 (p-value = 0.009). Conclusion Our study has concluded that civil unrest has an immediate impact on child health care evidenced by an increased proportion of acute medical complications at presentation. It affects more children coming from rural areas compared to those from urban communities.

背景 社会动荡（Civil Unrest）是一类集合术语，涵盖有限政治暴力、零星暴力集体行动，以及因政治、经济或社会变革引发不满的非暴力与轻度暴力集体行动。其对儿童与青少年的生命健康造成致命危害，且常导致民众难以获取包括医疗保健在内的基本公共服务。
目的 评估社会动荡对儿童医疗服务供给的影响，以因急性医疗并发症就诊入院的儿童占比作为评估依据。
方法 本研究采用基于医疗机构的回顾性对照研究设计，结合倾向得分匹配（Propensity Score Matching，PSM）与双重差分（Difference in Difference，DID）法（即PSM-DID法）开展研究。
研究场景与对象 本研究在巴希尔达大学蒂贝贝-吉翁专科教学医院儿科病房收治的儿童中开展。研究回顾性收集了2023年1月1日至2023年7月31日（社会动荡前阶段）以及2023年8月1日至2024年2月29日（社会动荡发生阶段）的医疗记录数据。研究通过Microsoft Excel依据医疗记录编号（Medical Record Number，MRN），从健康管理信息系统（Health Management Information System，HMIS）登记库中随机选取632名研究对象，其中干预组345例、对照组247例，分组依据为是否为农村居民（即干预分配条件）。
结果 本研究对7项协变量实施了倾向得分匹配。未匹配样本中，7项协变量中有2项存在组间显著差异。匹配后样本中，倾向得分匹配成功校正了所有协变量的偏倚。结果显示，社会动荡使农村居民就诊时的急性医疗并发症发生率显著升高，双重差分值为0.241（p值=0.009）。
结论 本研究证实，社会动荡对儿童医疗保健存在即时负面影响，表现为就诊时急性医疗并发症占比升高；相较于城市社区儿童，该影响对农村来源儿童更为显著。