Raphael E, et al. - In the present study, the researchers analyzed the relationship of place-based socioeconomic factors with disease distribution by contrasting hospitalisation rates in California in 2001 and 2011 by zip code median household income. The sample consisted of all hospitalised adults over 18 years old residing in California in 2001 and 2011 who were not pregnant or incarcerated. This comprised all acute-care hospitalisations in California involving 1,632 zip codes in 2001 and 1,672 zip codes in 2011. Findings revealed that there were 1.58 and 1.78 million hospitalisations in California in 2001 and 2011, respectively. Hospitalization rates among Californians living in low- and middle-income zip codes increased from 2001 to 2011. A granular description of disease burden was provided by the integration of spatially defined state hospital discharge and federal zip code income data. This method can help identify high-risk areas and evaluate interventions in public health that address health disparities.