Pneumonia and influenza hospitalizations in elderly people with dementia

To compare the demographic and geographic patterns of pneumonia and influenza (P&I) hospitalizations in older adults with dementia with those of the U.S. population and to examine the relationship between healthcare accessibility and P&I.

Observational study using historical medical claims from the Centers for Medicare and Medicaid Services (CMS) and CMS records supplemented with information derived from other large national sources.

Retrospective analysis of medical records uniformly collected over a 5-year period with comprehensive national coverage.

A study population representative of more than 95% of all people aged 65 and older residing in the continental United States.

Six million two hundred seventy-seven thousand six hundred eighty-four records of P&I between 1998 and 2002 were abstracted, and county-specific outcomes for hospitalization rates of P&I, mean length of hospital stay, and percentage of deaths occurring in a hospital setting were estimated. Associations with county-specific elderly population density, percentage of nursing home residents, median household income per capita, and rurality index were assessed.

Rural and poor counties had the highest rate of P&I and percentage of influenza. Patients with dementia had a lower frequency of influenza diagnosis, a shorter length of hospital stay, and 1.5 times as high a rate of death as the national average.

The results suggest strong disparities in healthcare practices in rural locations and vulnerable populations; infrastructure, proximity, and access to healthcare are significant predictors of influenza morbidity and mortality. These findings have important implications for influenza vaccination, testing, and treatment policies and practices targeting the growing fraction of patients with cognitive impairment.