One percent of the U.S. population accounted for 22 percent of all healthcare spending in 2009 while the lower spending half of the population accounted for only 2.9 percent, according to a report from the Agency for Healthcare Research and Quality (AHRQ).

A statistical brief on the data released by AHRQ also noted some trends in the numbers. While the concentration of healthcare spending among the top one percent has waned somewhat since the mid-1990s when the top one percent of spenders accounted for 28 percent of healthcare spending in 1996, a large number of healthcare spenders retained their ranking from the previous year. Of the individuals in the top percent of spending for 2008, one-fifth maintained this ranking in 2009; three out of four individuals in the bottom half of spending maintained their ranking.

AHRQ’s report also provided characteristics of those most and least likely to be big healthcare spenders.

“Relative to the overall population, those who remained in the top decile of spenders were more likely to be in fair or poor health, elderly, female, non-Hispanic whites and those with public-only coverage,” wrote the authors. “Those who remained in the bottom half of spenders were more likely to be in excellent health, children and young adults, men, Hispanics and the uninsured.”

Overall, 2.8 percent of the total U.S. population reported poor health in 2009, with another 8 percent reported to be in fair health. The percentages of individuals in the top decile of spenders reporting poor or fair health were 23.9 percent and 29.6 percent, respectively.

Some other notable findings:

• More than one-fourth of those in the bottom half of spenders for 2008 and 2009 were uninsured.
• Nearly 60 percent of patients in the top 10 percent of spenders were women.
• More than 80 percent of patients in the top 10 percent were white.
• Individuals 65 and older make up 13 percent of the overall population, but account for 43 percent of the top decile of healthcare spending.

Just how much healthcare spending gets an individual into the top group of spenders? The average per capita spending for the top one percent was $90,061, while the top 10 percent accounted for just under $24,000 in per capita expenses. Individuals in the bottom half of the healthcare spending distribution had a mean expenditure of $232.

The total healthcare bill in the U.S. was $1.26 trillion in 2009, according to AHRQ.

“Studies that examine the persistence of high levels of expenditures over time are essential to help discern the factors most likely to drive healthcare spending and the characteristics of the individuals who incur them,” wrote the authors.