In order to evaluate whether the introduction of this premium has a differential effect on enrollment in KCHIP 3 by child health type, we use medical claims data from the Kentucky Medical Management Information System (KYMMIS) claims data warehouse for the sample of 46,068 children for the years 2001-2005.
The KCHIP 3 Sample for the Survey of Premium Nonpayment
Soon after the introduction of the premium, the Kentucky Cabinet for Health and Family Services requested that we survey families that lost KCHIP coverage due to premium nonpayment to ascertain why these families chose not to pay the new CHIP premium, what their sociodemographic and health characteristics were, and whether they obtained an alternative source of health coverage.
Table 2 presents demographic information from the KCHIP eligibility records for children in the responding families, all children from the universe of families surveyed, and the universe of KCHIP enrollees for the month of January 2004.
A comparison of children in the universe of families surveyed to children enrolled in KCHIP in January 2004 provides some insight into how children who lost coverage compare to the typical enrollee.
We are interested in modeling the family decision to end a child's spell of KCHIP 3 coverage and how differences in premium levels and health status impact that decision.
To empirically analyze this relationship, the duration of the KCHIP 3 enrollment spells described earlier is estimated using a Cox proportional hazard model with time-varying covariates to model the yearly recertification process and introduction of the premium.
Instead, we use the average monthly exit probability in the KCHIP 3 sample, 3.18%, as an estimate of the average hazard when interpreting the coefficients of the model.
Our findings (Table 1c) indicate that children in Arizona were 10 percent less likely to re-enroll in the 101-150 percent of FPL category of KidsCare (p < .01) after the implementation of the new premium and that children in Kentucky may have also experienced a reduction in their re-enrollment rate in KCHIP III of 5 percent (p < .33).
However, there was a significant increase in the average monthly caseload for KCHIP II of 638 children or 2 percent (p = .02) following the adoption of the new premium in KCHIP III.
In Kentucky, under Scenario 2, spending would fall by an additional $885,740 due to decreased KCHIP III enrollment, generating a total savings of $1,300,939.
Table 2: Time Series Estimates of Caseload Changes in Public Insurance Programs in Kentucky and Arizona, 2001-2005 Arizona KidsCare O-150 Percent Medicaid of the SOBRA FPL All Children * Ages Average monthly 1,275 -1,155 premium effect (p=.37) (p=.03) ([double dagger]) Premium effect as a 1.7% -5.3% percent of premium- paying caseload Kentucky KCHIP III Medicaid KCHIP II ([dagger]) Average monthly 2,126 634 -3,262 premium effect (p=.14) (p=.02) (p<.Ol) ([double dagger]) Premium effect as a 0.7% 2.0% -18.1% percent of premium- paying caseload * Medicaid SOBRA Children are children ages 1-5 with family incomes up to 133 percent of the FPL and infants under age 1 with family incomes up to 140 percent of the FPL.