Evaluation of New York State's Child Health Plus: Methods

Background. The State Children's Health Insurance Program (SCHIP) is the la rgest public investment in child health care in 30 years, targeting 11 mill ion uninsured children, yet little is known about the impact of health insu rance on uninsured children. In 1991 New York State implemented Child Healt h Plus (CHPlus), a health insurance program that was a prototype for SCHIP. A study was designed to measure the association between CHPlus and access to care, utilization of services, and quality of care. Methods. The setting was a 6-county region in upstate New York (population 1 million) around and including the city of Rochester. A before-and-during design was used to compare children's health care for the year before they enrolled in CHPlus versus the first year during CHPlus, for 1828 children ( ages 0-6.99 years at enrollment) who enrolled between November 1, 1991 and August 1, 1993. An additional study involved 187 children 2 to 12.99 years old who had asthma. Parents were interviewed to assess demographic characte ristics, sources of health care, experience with CHPlus, and impact of CHPl us on their children's quality of care and health status. Medical charts we re reviewed to measure utilization and quality of care, for 1730 children 0 to 6.99 years and 169 children who had asthma. Charts were reviewed at all primary care offices and at the 12 emergency departments and 6 public heal th department clinics in the region. CHPlus claims files were analyzed to d etermine costs during CHPlus and to impute costs before CHPlus from utiliza tion data. Analyses. Logistic regression and Poisson regression were used to compare t he means of dependent measures with and without CHPlus coverage, while cont rolling for age, prior insurance type, and gap in insurance coverage before CHPlus. Conclusions. This study developed and implemented methods to evaluate the a ssociation between enrollment in a health insurance program and children's health care. These methods may also be useful for evaluations of SCHIP.