From 1992 to 1995, researchers at the University of California, San Francisco, studied access to primary care in selected urban California communities. The research was designed to assess whether hospitalization rates for certain chronic conditions typically managed by timely outpatient care are valid and useful measures of community access to care.
Using hospital discharge and census data, the researchers calculated hospitalization rates for five "ambulatory care sensitive" (ACS) conditions—asthma, hypertension, congestive heart failure, chronic obstructive pulmonary disease and diabetes—among 250 zip code clusters in California.
Among the investigators' key findings:
- Communities where people perceive their access to care as the lowest have the highest rates of hospitalization for ambulatory care sensitive conditions.
- Hospitalizations for ambulatory care sensitive conditions were higher in communities with greater proportions of uninsured and Medicaid patients, and higher in areas where greater proportions of residents said they had no regular place to obtain health care.
- Variations in physician practice styles or in patients' propensity to seek care for medical symptoms could not explain variations in hospitalization rates for ambulatory care sensitive conditions.