Place and Health: Preventable Hospitalizations for Adults in the Central Valley of California

Background
Rates of hospitalization for preventable conditions measure the burden of disease that could be avoided with increased access to preventive care.  There is ongoing debate about how other community level social and environmental factors influence these admissions.

Methods
Analysis was conducted using the 2010 California Office of Statewide Health Planning and Development (OSHPD) discharge database, for 8 Central Valley counties. A summary preventable hospitalization score was created based on the AHRQ prevention quality indicators.  US Census and other data were used to incorporate zip-code level factors including racial composition, distance from hospital, pollution burden and poverty rates.   OLS and negative binomial regression for preventable conditions were calculated and mapped to illustrate the variance in hospitalization rates by zip code across the Central Valley, controlling for zip-code level factors. 

Results
Average rate of preventable disease hospitalizations is 121/10,000. Zip codes with high concentrations of families in poverty are associated with a 45% increase in preventable disease hospitalizations for adults age 20 and older.  As pollution burden increases by 10%, hospitalizations rates increase by 10%.    Because of high rates of respiratory admissions, the summary score was disaggregated. Communities with high concentrations of African American residents and families in poverty are associated with higher rates of preventable respiratory hospitalizations (127% and 40% relative increase, respectively.)

Conclusions
Understanding the geographic distribution of disease and impact of community level factors is essential to expanding access to care and preventive resources to improve the health of California’s most underserved population.