By Darrell A. Hughes 

WASHINGTON -- The U.S. Census Bureau said the number of uninsured Americans increased in 2008 to 46.3 million, compared to 45.7 million in 2007.

The bureau also said the U.S poverty rate of 13.2% in 2008 was an increase from 12.5% in 2007. This was the largest annual poverty rate increase since 2004, the bureau said. The statistics released Thursday cover the first full year of the current recession. The median -- or midpoint -- household income declined slightly to $50,303.

The data underscore the need to revamp the U.S. health-care system, President Barack Obama said, adding that more recent surveys show that the situation has grown worse since the recession deepened last September.

"Over the last 12 months, it's estimated that the ranks of the uninsured have swelled by nearly six million. That's 17,000 men and women every single day," the president said in remarks at the White House.

The report, compiled in March, also said the number of people covered by government health-care programs Medicare and Medicaid increased to 87.4 million in 2008 from roughly 83 million in 2007. The number of people covered by Medicare and Medicaid has steadily increased annually over the past eight years.

However, those covered by private health insurance decreased to 201 million in 2008, down from 202 million in 2007. Census Bureau officials said during an online briefing on the figures that overall totals for those uninsured were offset by increases in government health programs and the decrease with those covered by private plans.

After outlining his health-care plans to Congress Wednesday, Mr. Obama's pitch was to a friendlier audience Thursday: a group of nurses who support his proposed overhaul.

"Few people understand as well as you why today's health-care system so badly needs reform," Mr. Obama told members of the American Nurses Association.

He repeated the goals for health-care legislation outlined in Wednesday's prime-time address, and again pleaded for urgent action.

"If there are real concerns about any aspect of my plan, let's address them. If there are real differences, let's resolve them," Mr. Obama said. "But we have talked this issue to death, year after year, decade after decade and the time for talk is winding down."

—Henry J. Pulizzi contributed to this article.

Write to Darrell A. Hughes at darrell.hughes@dowjones.com