Estimating the Effect of Hospital Admission on Health Care Outcomes and Spending Among Persons With Dementia : A Quasi-experimental Study.

BACKGROUND: Because transitions in care settings can be confusing for persons with dementia (PWD), hospital admissions can negatively affect their physical and cognitive function. However, the effect of hospital admissions on patient outcomes and health care spending remains largely unknown. OBJECTIVE: To estimate the effects of hospital admissions on health outcomes and health care spending among PWD. DESIGN: Quasi-experimental instrumental variable method, using emergency physicians' admission propensity as the instrument. SETTING: United States. PATIENTS: Medicare fee-for-service beneficiaries aged 66 years or older with dementia who visited an emergency department (ED) in 2017 to 2019. MEASUREMENTS: Death, inpatient days (excluding the index hospital admission), and health care spending (excluding the index ED visit and hospital admission) within 30 and 90 days of ED visits. RESULTS: Among 872 085 ED visits (62.9% women; mean age, 83.1 years) included in the analysis, 482 208 (55.3%) resulted in hospital admission. There was no evidence that hospital admission was associated with 30-day mortality rate (adjusted risk difference, -2.6 percentage points [pp] [95% CI, -5.2 to 0.1 pp]) or inpatient days (adjusted difference, 0.1 days [CI, -0.2 to 0.5 days]). Hospital admission was associated with higher 30-day health care spending (adjusted difference, $2547 [CI, $1390 to $3703]). Patterns were similar for 90-day outcomes. LIMITATION: Residual confounding. CONCLUSION: Among Medicare beneficiaries with dementia who visited an ED, there was no evidence that hospital admission was associated with mortality rates. Under conventional statistical criteria, an effect of hospital admissions between a 5.2-pp decrease and a 0.1-pp increase in 30-day mortality rates was highly compatible with the data. On the contrary, hospital admission was associated with higher health care spending. PRIMARY FUNDING SOURCE: None.