Association between healthcare utilization patterns and long-term all-cause mortality after acute myocardial infarction discharge in South Korea

Acute myocardial infarction (AMI) is a disease associated with high mortality. Therefore, early identification of high-risk patients and timely intervention are critical to improving long-term survival. This study aims to find the association between long-term all-cause mortality after AMI discharge using healthcare utilization patterns. Using the National Health Insurance Service-National Sample Cohort in South Korea (2011-2019), we included patients who survived for 120 days after AMI discharge. Four healthcare utilization patterns were identified using the latent class linear mixed model. The high-utilization group was characterized by the highest number of outpatient visits, the longest length of stays, and greatest health expenditure than other groups. In contrast, the decreasing-utilization group showed a declining trend in these components over time. We estimated the hazard ratios for all-cause mortality after 120 days from AMI discharge using the Cox-proportional hazard model. Of 3,535 individuals, 266 (7.5%) died and the mean age were 74.0 years (SD = 10.2). Among the elderly population (over 65 years), high-utilization (HR = 1.96; 95% CI, 1.13-3.42) and second-high-utilization (HR = 2.05; 95% CI, 1.22-3.43) groups had a significantly higher mortality risk than the decreasing-utilization group. This study confirmed the association between healthcare utilization patterns and long-term mortality among the elderly. Therefore, healthcare utilization patterns can be considered a predictor of long-term all-cause mortality after AMI discharge.