After a couple of years of modest growth, health care spending leapt at a much higher than expected rate last year, according to a recent report.

The average amount spent on the privately insured climbed by about 4.6 percent in 2011, up to $4,547 per person. That's far more than the 3.8 percent uptick in 2010, according to a recently released study by the Health Care Cost Institute. Consumers spent about $735 out-of-pocket on health care, up by $32, with costs covered by insurance rising at a similar rate.

"While it's hard to know whether this means spending levels are going to continue rising, it clearly is a signal that we have to pay attention to," Martin Gaynor, board chairman of the institute, said in a press release. "We need to continue studying these data to see whether this acceleration in spending growth is the beginning of an upward trend that will return us to pre-recession levels."

The institute gathered its data based on the claims of 40 million people with employer-sponsored health insurance plans, up 7 million people from the previous year's sample. All told, the organization estimates that total private health insurance spending totaled $709.2 billion, a 4.2 percent increase, year over year.

Rising prices was the main cause of increased spending, according to the report, with costs increasing in all major categories of health care. Outpatient care saw the largest increase, while spending on prescriptions slowed.

Here are some other highlights from the study:

  • The Northeast portion of the country had the highest per-person spending at $4,659, while the West had the lowest at $4,358.
  • In terms of age groups, spending on children under age 18 grew the fastest, up 2.1 percentage points to 7.7 percent. That's twice the rate of spending when compared to consumers ages 19 to 44, or 55 to 64.
  • The cost split for care between insurers and patients stayed relatively the same at 83.8 percent and 16.2 percent, respectively. On average, insurers paid about $3,812 per person last year.
  • Those with private insurance used more outpatient services and had more procedures performed last year, and ED visits increased by 3.7 percent.