Children's Preventive Care Use under Two Mature Medicaid Managed Care Plans in California

Article excerpt


The Santa Barbara Health Initiative (SBHI) and the Health Plan of San Mateo (HPSM) are two of the longest-running 1915(b) waiver programs in the United States; the SBHI was initiated in 1982 and the HPSM in 1987. As such, they provide a unique opportunity to investigate children, s preventive care use in mature Medicaid managed care (MMC) programs.

Most studies of MMC have focused on cross-sectional program effects from newly enrolled Medicaid participants or have explored pre/post program effects in early implementation years. In addition, previous studies could not always reliably gauge the impact of MMC because enrolled populations differed in systematic ways from non-enrolled comparison populations.

In this article, we examine preventive care use among infants and toddlers continuously enrolled in the SBHI and HPSM programs for 6, 12, and 24 months since birth during the years 1989-92. In particular, we investigate the extent to which children in two county-organized managed care health systems were compliant with national guidelines for the receipt of health supervision visits and childhood immunizations and whether improvements in preventive care use were realized as the programs matured.

Furthermore, we broke out the analysis by Medicaid eligibility category. In particular, we stratify between Aid to Families with Dependent Children (AFDC) enrollees and all other non-disabled enrollees to examine whether MMC differentially affected these groups. Because children enrolled under the poverty-related expansions are likely to be from families with higher income on average and because of the increased enrollment of immigrants in Medi-Cal (California's Medicaid program) during the early 1990s, the composition of other eligibility groups has changed over time. The greater diversity in background and the possibility for differential health status among different eligibility categories are potentially important distinctions that have not been examined for children in other research.


A recent study of the preventive care use of children enrolled in California's traditional fee-for-service (FFS) Medi-Cal in 1989 and 1992 found virtually no improvement in either the percentage of children who had any recommended well-child visits (46-47 percent in both years), the percentage of well-child visits that were made (44 percent in both years), or the percentage of recommended childhood immunizations received by these children from 1989 to 1992 (48 percent in 1989 and 50 percent in 1992) (Gavin et al., 1998; Herz, Stredl, and Albers, 1996).

The only significant improvements seen in these measures occurred among infants (less than 12 months old at the end of the year), but the rates of compliance with national standards remained very low. The percentage of infants enrolled in the FFS Medi-Cal program who had any well-child visits increased from 51 percent in 1989 to 62 percent in 1992, the percentage of recommended visits made by infants increased from 35 percent to 41 percent, and the percentage of recommended immunizations received by infants increased from 44 percent to 48 percent (Herz, Stredl, and Albers, 1996).

Other studies have found equally low rates of preventive care use among Medicaid children (U.S. Government Accounting Office, 1993; Gavin, Farrelly, and Simpson, 1998). One study of immunization coverage rates among 2-year-olds continuously enrolled in the Tennessee Medicaid program from birth found that the proportion who were up to date in their basic series of childhood immunizations peaked at 50 percent for those born in 1982 and 1983 and decreased to 44 percent for those born in 1989 (Griffin et al., 1995).

MMC presents opportunities for increased use of preventive care among Medicaid children. The assignment of a primary care gatekeeper under these plans is designed to enhance access to routine primary and preventive care. …