Functional Differentiation Among Medical Institutions During COVID-19 State of Emergency Periods: Autoregressive Integrated Moving Average Analysis of Percutaneous Coronary Intervention Using Diagnosis Procedure Combination Data

The COVID-19 pandemic significantly impacted healthcare delivery systems worldwide, with medical institutions facing the dual challenge of COVID-19 care and maintaining regular services. However, the relationship between institutional characteristics and changes in clinical practice during the pandemic remains unclear. This study evaluated how hospital characteristics affected percutaneous coronary intervention (PCI) implementation during the pandemic by analyzing Diagnosis Procedure Combination (DPC) data from April 2018 to December 2021. We stratified 634 hospitals by PCI volume (High/Middle/Low) and COVID-19 response level (High/Middle/Low) and employed autoregressive integrated moving average models with exogenous variables to quantify changes during state of emergency periods. Results revealed differential impacts based on institutional characteristics. In PCI volume stratification, high and middle-volume facilities showed significant reductions in both emergency PCIs (5.0% and 5.1%, respectively) and elective PCIs (9.6% and 10.8%, respectively). In COVID-19 response stratification, high-response facilities demonstrated the largest decreases in elective PCIs (17.7%), compared to medium-response (8.5%) and low-response facilities (6.4%). High COVID-19 response facilities had a greater proportion of public hospitals (62.1%) and fewer advanced treatment hospitals (4.9%) compared to low-response facilities (43.0% and 21.2%, respectively). These findings suggest that functional differentiation among medical institutions during the pandemic resulted from complex interactions between historical roles, management constraints, and institutional priorities. Our study provides important implications for medical service delivery system planning for future infectious disease outbreaks, emphasizing the need for planned role allocation and appropriate management support systems.