This research compared healthcare services utilization among older persons living in urban and rural Vietnam and determined the key factors contributing to their differences. A nationally representative sample of 3,049 older Vietnamese people in 2019 was used with multivariate logistic regressions and Poisson regressions to identify factors influencing the probability and frequency of service utilization. The standard concentration index (CI) and Erreygers concentration index (EI) were applied to measure the differences. The extension of the Oaxaca-Blinder decomposition was used to examine the rural-urban differences in healthcare services utilization and quantify factors contributing to the differences. CIs and EIs were relatively small and nearly zero, meaning that both inpatient service utilization and outpatient service utilization were equally distributed across all household wealth quintiles, regardless of their residence of living. Oaxaca-Blinder decomposition analysis results revealed statistically significant differences between rural and urban older persons in outpatient service utilization, in terms of its probability and frequency. Rural persons had 4.9% lower in the probability of outpatient services utilization than their urban counterparts. Similarly, rural residents had 3.033 times lower in the frequency of outpatient services utilization than urban residents. The use of health insurance during medical treatments and poor health status were two significant determinants explaining the urban-rural differences in healthcare utilization among older adults. Based on the crucial findings, continual development of the health insurance scheme and investment is recommended to support the rural older population in accessing healthcare. Future research opportunities include exploring a more comprehensive understanding of this field, such as examining the factors influencing the choice of healthcare facilities, reimbursement rates, and out-of-pocket expenses for older individuals in urban and rural areas. Additionally, longitudinal studies are recommended to investigate causal relationships in healthcare service utilization among older Vietnamese.

Keywords: Erreygers concentration index; Oaxaca-Blinder; Vietnam; concentration index; health services utilization; older persons; socio-economic differences.

本研究比较了居住在越南城市和农村地区的老年人的医疗服务利用情况，并确定了导致差异的关键因素。使用2019年全国代表性样本中的3,049名老年人，通过多元逻辑回归和泊松回归来识别影响服务利用率概率和频率的因素。应用标准集中指数（CI）和Erreygers集中指数（EI）来测量差异。扩展的Oaxaca-Blinder分解被用来分析农村与城市地区在医疗服务利用上的差异，并量化导致这些差异的因素。CIs和EIs相对较小且接近于零，这意味着无论居住地如何，住院服务利用率和平诊服务利用率在所有家庭财富五分位数中均等分布。

Oaxaca-Blinder分解分析结果显示，在门诊服务使用概率和频率方面，农村老年人与城市老年人之间存在统计学上的显著差异。具体来说，农村居民的门诊服务利用概率比城市居民低4.9%；类似地，农村居民的门诊服务利用率也仅为城市居民的3.033倍。

在医疗期间使用健康保险和个人健康状况不佳是解释城乡老年人医疗服务利用差异的两个重要因素。基于这些关键发现，建议继续发展和完善健康保险制度，并投资于支持农村老年人获取医疗服务方面的工作。未来的研究机会包括对这一领域进行更全面的理解，例如研究影响医疗设施选择、报销率和自付费用的因素等。此外，还推荐进行纵向研究以调查越南老年人在医疗服务利用方面的因果关系。

关键词：Erreygers集中指数；Oaxaca-Blinder；越南；集中指数；卫生服务利用率；老年人；社会经济差异。