However, the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) report also noted there are still dramatic racial disparities in kidney failure rates between black and white Americans.

Cautiously Optimistic

The 2003 rate for new cases of kidney failure was 338 per 1 million population, down slightly from 2002. The average annual increase has been less than 1 percent since 1999, compared to an average annual increase of 5 percent in the previous decade.

The four-year trend from 1999 to 2003 makes researchers cautiously optimistic that rates have stabilized. Careful control of blood pressure and diabetes, the launch of private and government programs to increase awareness and improve care, and drug therapy were cited as factors that have contributed to this stabilization.

The report noted that diabetes and high blood pressure remain the leading causes of kidney failure. They account for 44 percent and 28 percent of all new cases, respectively. While rates for diabetes-related new cases of kidney failure among whites under age 40 were at the lowest since the late 1980s, there's been no change among blacks in the same age group.

Increasing and Aging Population

Even though there's been success in preventing kidney failure and improving the health and survival of people with the disease, more Americans than ever before are developing and living with kidney failure, the report said. That's due to an increasing and aging population.

In 2003, nearly 537,000 people in the United States received dialysis or had a kidney transplant, at a cost of $18.1 billion to Medicare and another $9.2 billion to private insurers and patients. It's estimated another 10 million people have early kidney disease, and most aren't aware of it.

The findings will be presented next month at the American Society of Nephrology annual meeting.

More information: The American Academy of Family Physicians has more about kidney failure.