'More dialysis not always better' headlines distort newly published findings

[plugger]

(an experienced voice of sanity)

3/26/2012

By Dori Schatell, MS

A new analysis of data from the Frequent Hemodialysis Network studies by Dr. Yoshio Hall is making the rounds—and the headlines it has inspired make it seem as if the benefits of longer and/or more frequent hemodialysis aren't really very important after all. The finding: there wasn't much in the way of "objective" improvement in patients' physical activity level. That means more dialysis is not always better, right?

Wrong.

As a passionate advocate for peritoneal dialysis and home hemodialysis, I've had a few conversations with others in the renal community already about this new study. The point we need to keep in mind is that, while physical improvement from more frequent hemodialysis would be beneficial, subjective, patient-perceived improvement is what predicts reduced hospitalization and improved survival. To save lives (and dollars) in the ESRD Program, we don't need to improve actual physical function. We need to improve how patients feel about their physical function. And, the FHN short daily trial did just that.

Measuring improvement
Health-related quality of life (HRQOL) is a way of assessing patients' perceptions of their own mental and physical function, and how burdensome they find kidney disease to be. Surveys like the SF-36, RAND-36, and KDQOL-36 (now required annually by CMS as a clinical performance measure) are valid and reliable, and higher scores predict lower hospitalization and death as strongly as Kt/V or serum albumin levels. In fact, each one-point increase in physical functioning reduces a patient's relative risk of death by 2%. (Click here for details).

What the FHN trials did find among those who did short daily hemodialysis were significant improvements in physical functioning on the RAND-36 (3.4 points worth, + 0.8 points). This suggests that patients who used this therapy really did feel that they were physically better (whether or not they actually were). 

Further, the FHN trials found significant reductions in left ventricular mass in the participants who did short daily hemodialysis, and lower blood pressure. Both of these suggest that there were, in fact, important physiologic improvements that predict longer survival—though others may have been missed by other measures that were perhaps too basic to pick up subtle physical gains. (A note: Exercise does objectively improve physical function among people on dialysis. A whole body of research demonstrates this.)

What about the nocturnal branch of the FHN study?  Are the highly touted benefits of nocturnal hemodialysis just hype?  No, the benefits are real. Unfortunately, this study was not able to recruit enough subjects to obtain statistical power to detect a difference. And, I strongly suspect (though I was not a researcher on this study) that there was not enough separation between the control and experimental group dialysis doses to create a difference.

Nevertheless, more kidney replacement therapy—longer and more frequent hemodialysis—is more physiological. It's just plain common sense.

Ms. Schatell is Executive Director of the non-profit Medical Education Institute, which created www.homedialysis.org, www.lifeoptions.org, www.kidneyschool.org, and www.kdqol-complete.org. She is coauthor with Dr. John Agar of a new patient book entitled, Help, I Need Dialysis! For more details, visit www.lifeoptions.org/help_book.