The Commonwealth Fund report examines performance variations among states' child health systems for all 50 states, plus the District of Columbia, ranking for each indicator and the five dimensions of performance -- access, quality, costs, equity, and potential to lead healthy lives.

Thirteen states: Iowa, Vermont, Maine, Massachusetts, New Hampshire, Ohio, Hawaii, Rhode Island, Kentucky, Kansas, Wisconsin, Michigan, and Nebraska emerge at the top quartile of the overall performance rankings.

The 13 states at the bottom quartile of the overall performance rankings are: lllinois, New Mexico, Alaska, New Jersey, Oregon, Arkansas, Nevada, Texas, Arizona, Louisiana, Mississippi, Florida and Oklahoma.

There is wide variation in children's access to care and healthcare quality across the United States. The proportion of children who are uninsured ranges from 5 percent in Michigan to 20 percent in Texas.

The proportion of children who have regular medical and dental preventive care ranges from 75 percent in Massachusetts to 46 percent in Idaho.