Children with private health insurance are still more likely to get their prescriptions filled, regardless of cost concerns, than other U.S. residents, but the situation is getting better for most other demographic groups and worse for privately insured children.

Ellyn Boukus and Emily Carrier, researchers at the Center for Studying Health System Change (HSC), Washington, have published data supporting that conclusion in a prescription drug access paper.

Boukus and Carrier based on the paper on an analysis of data from 2010 and 2007 HSC telephone surveys. The sample included about 18,000 U.S. residents in 2007 and 17,000 in in 2010.

The researchers estimated the unmet need for prescription drugs by having poll staffers ask the following question: “During the past 12 months, was there any time you needed prescription medicines but didn’t get them because you couldn’t afford it?”

The recession rolled in starting in 2007, but Walmart started offering many generic prescriptions for $4 each in May 2006 and greatly expanded the program in 2007. Many competitors followed suit.

Possibly because of the effects of the $4 prescription programs, the percentage of HSC survey participants with unmet prescription needs held steady at about 13%.

The rate increased slightly, to 8.4%, from 8.2%, for Medicare enrollees ages 65 and older, and it increased to almost 31%, from about 27%, for Medicare enrollees younger than 65.

Only 4.2% of the participants with privately insured children admitted that the children had unmet prescription needs, but that percentage has increased from 2.4% in 2007.

For uninsured children, the percentage with unmet prescription needs increased to 14%, from 13%.

About 26% of insured people in fair or poor health reported having unmet prescription needs in 2010, up from about 23% in 2007.