Health care utilization and potentially preventable adverse outcomes of high-need, high-cost middle-aged and older adults: Needs for integrated care models with life-course approach

Purpose of the research: The success of modern health care increases life expectancy and prolongs the days of having multimorbidity and functional limitations; the so-defined "high need, high cost (HNHC)" state represents the extreme scenarios of care burden and complexity. This study aims to explore health care utilization and the risk of preventable adverse outcomes stratified by age and HNHC state.Materials and methods: We conducted a retrospective cohort study using the National Health Insurance (NHI) database. People aged >= 40 years were included and further stratified by age (middle-aged: 40-64 and older adults: 65) and HNHC state (top 10% of spending). Health care utilization and drug consumption across different groups were obtained. The multimorbidity frailty index (mFI) was developed for further analysis. Cox regression models were used to examine the associations between HNHC and adverse clinical outcomes (preventable hospitalizations, preventable emergency department visits, and mortality).Results: HNHC participants were older, had a higher mFI and drug consumption, and had higher health care utilization. Compared with non-HNHC participants, HNHC participants exhibited a 4.4-fold and 2.4-fold higher risk of preventable hospitalizations in middle-aged (HR=4.41; 95% CI, 4.17-4.65, p<0.01) and older adults (HR=2.44; 95% CI, 2.34-2.55, p<0.01). Similar risks were observed for preventable emergency department visits and mortality (all p<0.01).Conclusions: The HNHC state substantially increased health care utilization, polypharmacy, and potentially preventable adverse outcomes after adjustment for frailty. Intervention studies developing integrated care models using the life-course approach are needed to improve the quality of health care systems in super-aged societies.