Medicaid Pay for Performance Programs and Childhood Immunization Status

Introduction Although pay for performance (P4P) programs are being increasingly used by state Medicaid programs to provide incentives for managed care plans to provide high-quality care, no national study has examined the effects of these plans on commonly targeted outcomes such as childhood immunization rates. Methods Information from the 1999–2011 National Immunization Survey combined with information on state Medicaid P4P programs from the Centers for Medicare and Medicaid Services was used to study the effect of Medicaid P4P programs on the immunization status of children aged 19–35 months. Difference-in-difference-in-difference models were used to study whether adoption of Medicaid P4P programs was associated with higher immunization rates among Medicaid-eligible children relative to non–Medicaid eligible children within states that adopted Medicaid P4P programs compared with states that did not. Linear probability models were used in all estimations, and models controlled for demographic factors. Results The study found no overall effect of Medicaid P4P on the chance that children aged 19–35 months had completed the 4:3:1:3:3:1 vaccination series. However, there was a 4 percentage point increase in the chance that a child 19–23 months had completed the series. Conclusions This study provides some evidence that Medicaid P4P programs may be helpful in improving childhood vaccination rates. Further study of the effects on other targeted outcomes as well as the effects of different P4P program designs may increase understanding of the potential role of these programs in improving the quality of health care.