Where Maine ranks nationally in its addiction to painkillers depends on how you measure it.

A federal report published in December ranked Maine No. 1 in the rate of residents getting publicly funded treatment for pain-pill addiction in 2008. A total of 386 of every 100,000 residents age 12 or older were admitted for treatment, more than eight times the national rate, according to the Substance Abuse and Mental Health Services Administration report.

But that doesn’t necessarily mean Maine has the most addiction. The ranking may also reflect differences in treatment programs, funding structures and reporting standards from state to state.

The latest national survey indicates that about the same percentage of Mainers over age 12 – just under 5 percent – admitted to abusing painkillers in 2009, as Americans did as a whole. By that standard, Oklahoma is the most addicted state, with 8 percent of residents saying they used painkillers for a nonmedical reason. But that survey is based on self-reporting.

Another measure is the rate of fatal overdoses.

Maine’s overall drug overdose rate was 10.5 per 100,000 residents in 2007, the most recent year reported by the U.S. Centers for Disease Control and Prevention. The national rate was about 9, while West Virginia had the highest rate – 21.1.

Those numbers are increasingly driven by prescription painkiller abuse, but also reflect illicit drugs and other prescription drugs.

A 2009 CDC study looked only at overdose deaths from prescription opiates. That study, based on 2006 overdose data, said Maine was one of 16 states with the highest rates of painkiller overdoses.

The report said only that Maine’s rate was significantly higher than the U.S. rate – 4.6 per 100,000 residents. It did not rank individual states.

Overdose rates also can be influenced by factors such as access to medical care and  prevention efforts.