National Hospitalization Trends and the Role of Preventable Hospitalizations among Centenarians in the United States (2000-2009).

Increases in life expectancy mean that an unprecedented number of individuals are reaching centenarian status, often with complex health concerns. We analyzed nationally representative hospital admissions data (200-2009) from the National Inpatient Study (NIS) for 52,618 centenarians (aged 100-115 years, mean age 101.4). We predicted length of stay (LOS) via negative binomial models and total inflation adjusted costs via fixed effects regression analysis informed by descriptive data. We also identified hospitalizations due to ambulatory care-sensitive conditions defined by AHRQ Prevention Quality Indicators. Mean LOS decreased from 6.1 to 5.1 days, while over the same time period the mean total adjusted charges rose from USD 13,373 to USD 25,026 in 2009 dollars. Black, Hispanic, Asian, or other race centenarians had higher cost stays compared to White, but only Black and Hispanic centenarians had significantly greater mean length of stay. Comorbidities predicted greater length of stay and higher costs. Centenarians admitted on weekends had higher costs but shorter length of stay. In total, 29.4% of total costs were due to potentially preventable hospitalizations for total charges (2000-2009) of USD 341.8M in 2009 dollars. Centenarian hospitalizations cost significantly more than hospitalization for any other group of elderly in the U.S.