麻豆果冻传媒影音

BALTIMORE, Aug. 1-Long-term peritoneal dialysis is riskier than hemodialysis, say Johns Hopkins researchers.

For the first year of treatment, there is little difference between the two forms of dialysis, reported Neil Power, M.D., of the university's Welch Center for Prevention, Epidemiology and Clinical Research.

But after the second year, the risk of death for those on peritoneal dialysis is about twice that of those on hemodialysis, especially for people who have cardiovascular disease, Dr. Powe and colleagues reported in the Aug. 1 online edition of Annals of Internal Medicine.

"There is clearly a benefit in choosing hemodialysis over peritoneal dialysis," Dr. Powe said, who was principal investigator of the Choices for Healthy Outcomes in Caring for ESRD study, known as CHOICE for short.

The CHOICE study followed 1,041 newly diagnosed patients as they chose a dialysis method and underwent treatment for a mean follow-up of 2.4 years. The study involved 82 dialysis clinics from across the U.S. There were 274 patients who initially selected peritoneal dialysis and 767 who selected hemodialysis.

The crude mortality rates were not significantly different at 2.4 years, the authors reported -- 21.2% for peritoneal dialysis and 24.4% for hemodialysis.

However, when the analysis was adjusted to take into account demographic, clinical and treatment factors, and laboratory data, the relative risk for death over the whole cohort for peritoneal dialysis was 1.61 (with a confidence interval of 1.13 to 2.30) and for patients in clinics offering both classes of treatment was 2.02 (with a confidence interval of 1.23 to 3.32).

One important factor was general health at baseline; the researchers found that patients whose initial choice was peritoneal dialysis tended to be healthier and of higher socioeconomic status than those who chose hemodialysis.

The researchers found that diabetes, age, and residual urine output at baseline did not appear to affect the risk of death. Cardiovascular disease at baseline, however, did increase the risk of death for patients undergoing peritoneal dialysis. The relative risk was 2.10, with a confidence interval of 1.36 to 3.25.

To further adjust for selection bias which occurs when healthier persons of higher socioeconomic status are more likely to undergo initial treatment with peritoneal dialysis, the researchers used propensity scores. Propensity scores assigned a probability to being treated initially with peritoneal dialysis. They then used these propensity scores in their regression models to account for selection bias. In the adjusted models that included the propensity scores, the relative risk of death remained significantly higher for patients on peritoneal dialysis (HR 1.74, CI 1.23-2.46).

"Until now, people with kidney disease have picked the kind of dialysis that best suits their lifestyle, sometimes switching from one method to the other," said Bernard Jaar, M.D., of the Welch Center, who was a co-author of the journal report.

Peritoneal dialysis remains a valid choice, he said, but physicians and patients need to be aware that in the long term there are factors that can affect its safety.

"It offers good quality of life," he said, "and as long as patients have no significant co-morbidities and maintain residual urine output, I think peritoneal dialysis could be a good option."

Currently, about 400,000 people in the U.S. are being treated for end-stage renal disease with either dialysis or transplantation, and the number is projected to rise to about 2 million by 2030, according to the 2003 report of the U.S. Renal Data System of the National Institutes of Health.

In an accompanying editorial, Dr. Gerald Schulman, M.D., of Vanderbilt said the central value of the CHOICE study is that it contributes to the "science of comparing different techniques of dialysis."

But because dialysis techniques are changing rapidly, Dr. Schulman said, the study's conclusion can't be taken as definitive. "The comparisons of greatest interest are between newer technologies and well-established technologies," he said.

The CHOICE study's "principal shortcoming is that it took aim at a moving target," Dr. Schulman concluded.

Related articles:

• Fast Diagnosis of Renal Failure With Novel Biomarker

• Heart Failure Drug Natrecor May Contribute to Renal Function Decline

Comment