Impact of a decline in Colorado Medicaid managed care enrollment on access and quality of preventive primary care services.

BACKGROUND: Beginning in 1997 the Colorado Medicaid program de-emphasized managed care and shifted children from enrollment in a health maintenance organization (HMO), which required an enrollee to have an assigned primary care physician, to either the unassigned fee-for-service (UFFS) program in which the enrollee was not required to have a primary care physician (PCP) or to the primary care physician program (PCPP) in which the enrollee was required to select a participating PCP if one was available. The proportion of Medicaid enrollee-months in HMOs dropped from 75.4% in 1997 to 29% in 2003, whereas the proportion of enrollee-months in UFFS programs during this time period increased from 18.6% to 45.6%, and the proportion in the PCPP increased from 5.5% to 25.3%. This shift of children from HMO managed care to the UFFS program provided a natural experiment to assess the impact of not having an assigned PCP on pediatric primary care services.

OBJECTIVE: We sought to assess whether an elective shift of children from Medicaid HMO managed care plans with an assigned PCP to the UFFS program without an assigned PCP restricted access to a primary care medical home, recommended health supervision visits, and age-appropriate immunizations.

METHODS: Published Colorado Health Plan Employer Data and Information Set (HEDIS) data for 1999-2003 were reviewed to determine if Colorado children enrolled in Medicaid managed care programs with an assigned PCP (HMO and PCPP) compared with the UFFS program were more likely to have any type of visit with a PCP, to have recommended health supervision visits, and to be fully immunized. In the analysis, "HMO total" refers to the average of all children participating in HMO plans. Kaiser Permanente was considered a benchmark because it had the highest immunization rates of all HMOs. "Total Colorado" refers to the average of all children enrolled in Medicaid including the managed care and UFFS options. For 2-year-olds, the 4:3:2:1:1 combination immunization included 4 diphtheria-tetanus-acellular pertussis vaccines, 3 oral poliovirus vaccines or inactivated polio vaccines, 2 hepatitis B vaccines, 1 Haemophilus influenzae type b vaccine, and 1 measles-mumps-rubella vaccine.

RESULTS: In 1999 the percentages of children 12 to 24 months of age having any type of visit with a PCP were >80% for the PCPP, Kaiser Permanente, and UFFS programs. However, although the proportion with any visit remained >85% in 2001 for children enrolled in the PCPP and Kaiser Permanente program, the percentage dropped 13.9% to 66.2% for children in the UFFS program. In 2001 the percentage of children with any type of PCP visit enrolled in the UFFS program (66.2%) was significantly lower than the total Colorado (73.6%) as well as the PCPP (85.7%) and Kaiser Permanente program (97.7%). Children 12 to 24 months of age enrolled in the PCPP in 2001 were 1.3 times more likely to have any type of visit with a PCP compared with those enrolled in the UFFS program. Children in the PCPP in 2001, 2002, and 2003 were 1.4, 1.9, and 2.6 times more likely, respectively, to have all 6 of the recommended health supervision visits compared with children enrolled in the UFFS program. Children 3 to 6 years old in the PCPP in 2001, 2002, and 2003 were 1.3, 1.5, and 1.4 times more likely, respectively, to have an annual health supervision visit compared with children enrolled in the UFFS program. In 1999, 2001, 2002, and 2003 2-year-old children enrolled in the PCPP were 2.0, 1.4, 1.5, and 1.8 times more likely, respectively, to be up-to-date with 4:3:2:1:1 vaccines compared with children enrolled in the UFFS program. In 1999, 2001, 2002, and 2003 adolescents enrolled in the PCPP were 1.8, 1.6, 1.3, and 1.6 times more likely, respectively, to be up-to-date with 2 measles-mumps-rubella vaccines compared with children enrolled in the UFFS program.

CONCLUSIONS: This study documents the diminishing ability of the Colorado Medicaid program to provide children access to the benefits of a medical home, including visits with PCPs, recommended health supervision visits, and immunizations as care was shifted to the UFFS program from HMO managed care. The high up-to-date immunization rates achieved by Kaiser Permanente suggest that differences in immunization rates reflect the effectiveness of the care processes rather than the characteristics of the Medicaid population.