NEW YORK - Kidney disease patients who are black or lack private health insurance are less likely to get matched up with a donor organ before needing to go on dialysis, a new study suggests.

Still, researchers said, as long as patients get a kidney transplant within a year or so of starting dialysis, any extra benefit of a pre-dialysis transplant may be low.

"It's a possible benefit, but it's not entirely clear," said Dr. Morgan Grams, who led the new study at the Johns Hopkins University School of Medicine in Baltimore.

She told Reuters Health the findings represent "just another disparity" for African American patients, in particular, who take longer to get on the waitlist for a donor kidney and are less likely to get one at all.

"Studies over the last 10 to 15 years have consistently shown that minorities have poorer access to transplantation," said Dr. Douglas Scott Keith, head of the kidney transplant program at the University of Virginia Medical Center in Charlottesville.

"This article basically shows that it's persisting, it hasn't gotten much better," Keith, who wasn't involved in the new study, told Reuters Health.

Grams and her colleagues looked at about 122,000 first-time kidney recipients who received their organ from a deceased donor off a transplant list between 1995 and 2011.

Nine percent of those patients had their kidney transplant before going on dialysis, and another 12 percent received a kidney within their first year on dialysis, the researchers reported Thursday in the Clinical Journal of the American Society of Nephrology.

African Americans were 56 percent less likely to receive a kidney before dialysis than whites - possibly because there was a delay in getting them on the transplant list or fewer matching donors, researchers said.

Typically, an available organ goes to the local patient who has been on the kidney transplant list the longest - but that person can be skipped if the organ is a direct match to the immune system of another patient high on the list.

People in the study who had private insurance were also three times more likely to get an early kidney than others.

Insurance is required for a transplant, so anyone with private insurance can get on the list early. Others aren't eligible for government-funded insurance until they're on dialysis.

It's still unclear whether receiving a kidney very early on improves the long-term outlook for patients with renal disease.

Pre-dialysis recipients and people who got their kidney within a year of starting dialysis were equally likely to survive for years after their transplant, the researchers found. Both did better than late-dialysis recipients.

"I would certainly not advocate postponing dialysis in the hope of getting a transplant without getting dialyzed," said Dr. Titte Srinivas, the head of transplant nephrology at the Medical University of South Carolina in Charleston, who also wasn't part of the research team.

For a patient who needs it, "A short duration of dialysis is not really detrimental to health."

Srinivas told Reuters Health what's most important is for anyone diagnosed with renal failure to get on the kidney transplant list as quickly as possible.

Health care reform could make that easier for some people, Grams noted, as more low-income patients will have access to insurance - and the transplant list.

"People don't realize that insurance makes such a huge difference," she said.

Keith said aside from the insurance issue, researchers are still grappling with how to distribute kidneys of all different qualities, from all different types of donors, to the people who need them most.

"We should be trying to make the system as fair as possible, and to limit disparities as much as possible," he said. "The question is how to do it."