Impact of child health insurance expansions on ambulatory care-sensitive hospitalizations in California

Background: Common chronic conditions in childhood, such as asthma or diabetes, can often be adequately managed in primary care. In 2001, nearly 350,000 children in California, however, lacked such primary care access because they were uninsured. In response, 18 counties across California (and more on the way) developed Children's Health Initiatives (CHIs) that were designed to enroll eligible children in Medicaid and the State Children's Health Insurance Program. The CHIs also aimed to expand coverage further through the design of county-based health insurance programs—known as Healthy Kids—for low-income children otherwise ineligible for existing programs.

Purpose: To assess the impact of increasing children's health insurance coverage rates on hospitalizations for ambulatory care sensitive conditions (ACSC). ACSC are conditions that should not typically result in hospitalization if they are well-managed in primary care settings.

Study Design: Analysis of publicly available, quarterly patient discharge data for California children ages 0-19 years between 1998 and 2005.

Main Outcome Measure: Proportion of total hospitalizations for eight ACSC. Conditions considered ACSC as defined by the Agency for Healthcare Research and Quality. These include asthma, bacterial pneumonia, diabetes short-term complications, gastroenteritis and dehydration, iron deficiency anemia, perforated appendix, and urinary tract infection.

Results: In the study period, there was an overall decrease in the number of ACSC hospitalizations and an increase in non-ACSC hospitalizations. Among all hospitalizations, 6.24% were for ACSCs in county-quarters in which there was an active CHI, statistically different from 6.12% for county-quarters with no CHI (P<0.0001), reflecting 1,265 fewer ACSC hospitalizations in county-quarters in which there was an active CHI during the study period. When restricted to low-income children, 6.85% of all hospitalizations were for ACSCs in county-quarters with an active CHI compared to 6.74% in county-quarters with no CHI (P<0.01). This reflects 607 fewer ACSC hospitalizations for low income children during the study period. When examined for each CHI, Riverside showed the greatest decrease in proportion of ACSC hospitalizations from pre-CHI to post-CHI compared to all other counties (8.02% to 6.36%, P<0.001).

Conclusion: This study suggests that the decrease in ACSC hospitalizations may be correlated with efforts to expand health insurance coverage in California. The decrease in proportion of ACSC hospitalizations is slight, and may be limited by the fact that many of the CHIs are only a year or less into full implementation. Further monitoring of the effects of the CHIs as they mature is needed.