What's cost got to do with it? Association between hospital costs and frequency of admissions among "high users" of hospital care

BACKGROUND: Efforts to curb healthcare spending have included interventions that target frequently hospitalized individuals. It is unclear the extent to which the most frequently hospitalized individuals also represent the costliest individuals. OBJECTIVE: To examine the relationship between 2 types of "high users" commonly targeted in cost-containment interventions-those incurring the highest hospital costs ("high cost") and those incurring the highest number of hospitalizations ("high admit"). DESIGN, SETTING, AND PATIENTS: Cross-sectional study of 2566 individuals with a primary care physician and at least 1 hospitalization within an academic health system from 2010 to 2011. MEASUREMENTS: Overlap between the population constituting the top decile of hospital costs and the population constituting the top decile of hospitalizations; characteristics of the 3 resulting high user subgroups. RESULTS: Only 48% of individuals who were high cost (>$65,000) were also high admit (≥3 hospitalizations). Compared to hospitalizations incurred by high cost-high admit individuals (n=605), hospitalizations incurred by high cost-low admit individuals (n=206) were more likely to be for surgical procedures (58 vs 22%, P<0.001), had a higher cost ($68,000 vs $28,000, P<0.001), longer length of stay (10 vs 5 days, P<0.001), and were less likely to be a 30-day readmission (17 vs 47%, P<0.001). CONCLUSIONS: Stratifying high admit individuals by costs and high cost individuals by hospitalizations yields 3 distinct high user subgroups with important differences in clinical characteristics and utilization patterns. Consideration of these distinct subgroups may lead to better-tailored interventions and achieve greater cost savings. Journal of Hospital Medicine 2013;8:665-671.