Background/Objectives: South Korea implemented a case management program for Medical Aid (MA) beneficiaries in 2003. This study evaluates the effect of case management on healthcare utilization among MA beneficiaries, with a focus on both outpatients and inpatients. Methods: This retrospective comparative study was conducted using the 2023 full dataset of MA beneficiaries. The propensity score matching method was used to match the case management group with the non-case management group, and differences in healthcare utilization were analyzed using a difference-in-differences analysis. Results: The case management group exhibited characteristics of a medically vulnerable population, with greater healthcare needs than those of the non-case management group. Case management interventions reduced outpatient days by 4.7 and outpatient medical costs by USD 327 per person annually. For long-term inpatients, it reduced inpatient days by 13.6 and medical costs by USD 2261 per person annually (p < 0.001). Conclusions: MA case management effectively reduced both outpatient/inpatient days and medical costs. As the effects may vary depending on the type of case management, developing diverse and detailed case management programs is necessary.

Keywords: Medical Aid; case management; healthcare utilization; inpatient; medical cost; outpatient.

背景/目的：韩国于2003年实施了针对医疗援助（Medical Aid，MA）受益者的个案管理计划。本研究评估了个案管理对MA受益者医疗服务利用的影响，重点关注门诊和住院患者。方法：这项回顾性比较研究使用了2023年MA受益者的完整数据集。采用倾向评分匹配法将个案管理组与非个案管理组进行匹配，并通过差异分析来分析医疗服务利用的差异。结果：个案管理组表现出医疗脆弱人口的特点，其医疗服务需求高于非个案管理组。个案管理干预措施使门诊天数每年减少4.7天，门诊医疗费用每人每年减少327美元。对于长期住院患者，它将住院天数减少了13.6天，医疗费用每人每年减少了2261美元（p 结论：MA个案管理有效降低了门诊和住院天数及医疗成本。由于效果可能因个案管理类型的不同而异，有必要开发多样且详细的个案管理计划。

关键词：医疗援助；个案管理；医疗服务利用；住院患者；医疗费用；门诊患者。