Home hemodialysis in this millennium: The return of the king?

Home hemodialysis in this millennium: The return of the king?
8/27/2008 11:12:22 AM

Alan Hull, MD

Those who have known me for a long time know that I've always believed that more therapy is better. This is what led me to transplant nephrology. However, with todays advancements, home hemodialysis, I believe, presents another way to pursue the goal of more therapy for more patients.

It has now been seven years since the monumental HEMO and ADEMEX trials (randomized controlled trials on the impact of dose on mortality in HD and PD, respectively) showed that increasing dialysis dose did not in fact increase survival. These results surprised many, including myself. However, upon reflection, I (like many others) came to a very simple conclusion: we're never going to be able to meaningfully increase the amount of therapy we deliver to patients with traditional in-center HD because of the logistical and economic limitations of a staff-intensive, shift system; nor PD, because of the fluid volume and the number of exchanges a patient can tolerate. If the amount of therapy is important, we have to radically change how and/or where we provide dialysis.

Data from the U.S. Renal Data System shows us that little has changed during the seven years since the results of HEMO and ADEMEX were published. The vast majority of patients still receive in-center HD three times per week, and a shrinking balance still does PD at home. What we have seen, however, is a quietly emerging trend of more patients returning to the roots of renal replacement therapy: home hemodialysis. I believe that home HD is the king of dialysis therapies, because of its inherent flexibility versus shift-limited in-center dialysis. The kidneys perform the way they do for a reason. By removing the schedule limitations of traditional dialysis we will be able to administer therapy in ways more like the naturally functioning kidney, improving patient well-being and quality of life.

I am not alone, evidenced by the growing body of literature supporting more frequent and/or longer-at-home HD.

Although home HD still represents less than 1% of the dialysis population, it is becoming the fastest growing segment, with growing industry support.

Why did we lose it?

As older readers may remember, dialysis started as home HD in the late 1960s. This was at least until multiple reimbursement changes (HR 1 in 1973, the composite rate system in the early 80s, and, later, separately billable IV drugs) facilitated the development and rapid expansion of institutional in-center HD at the expense of home HD.

To be fair, reimbursement was not the only factor hastening the decline of home HD, and not all patients are candidates. Home HD was difficult with existing equipment, and required a trained helper. In contrast, the in-center HD patient has no responsibility. PD addressed some of the technical challenges of home HD, and as such grew to be the primary choice for dialysis at home. However, PD peaked in the early to mid-1990s at 15% (Collins, personal communication) of the U.S. dialysis population, and has now declined to approximately 8%.

So what makes me think home HD is returning? I estimate that the number of patients doing HD at home has more than doubled in the past three years after a long period of decline. Lockridge In Virginia, Hoy in New York, Ting in California, and Lindsay and Perriatos in Canada created the environment for change, with their passion and encouraging results. However (and I can say this because they are all friends), they are zealots and were able convince their patients to do HD daily and/or at home overnight despite the cumbersome nature of conventional dialysis equipment.

Here in the states, Aksys PHD system (Libertyville, Ill.) was the first available system designed and indicated specifically for daily home therapy, but its economics and reliability limited its adoption. NxStages System One (Lawrence, Mass.) became available in mid-2005; the company reports 2,007 patients are on the machine as of October 2007, translating into an estimated increase in HD patients at home of over 100%. These numbers still remain small; the therapy skews to younger, male patients, and virtually none of these patients came from other home HD modalities.

Is this change good for patients and the health care system? Here are some well-established advantages to more frequent dialysis.

Blood pressure control. Any questions remaining that daily dialysis therapies can control blood pressure using fewer antihypertensive medications should be answered. This was a definitive finding in NxStages FDA trials, and the Goldfarb-Rumyantzev crossover study showed that the blood pressure control is attributable to daily therapy and is not maintained upon return to conventional dialysis. ² When initiating patients on NxStage daily home therapies, it has become standard practice to immediately reduce antihypertensive doses.

Volume control and LVH. Again, there is little debate that more frequent or longer therapy will improve fluid volume control vs. conventional 3x weekly HD therapy. I believe that the gravity of this will become increasingly obvious over time. Movilli showed that higher ultrafiltration rates are associated with higher mortalitity ³ and more frequent/longer therapies are able to achieve fluid control objectives at lower ultrafiltration rates. In addition, Culletons Canadian randomized study showing a reduction in LVH with nocturnal home therapy ⁴ is particularly important given the recruitment challenges of the NIHs study.

Phosphorus management. This topic is receiving increasing focus given the cardiovascular complications of patients, but Im not sure we all speak the same language. As a baseline, both conventional 3x weekly HD and PD do a poor job of phosphorus removal, and drugs are not without their limitations. Short daily HD, even with modest fluid volumes, removes more phosphorus than conventional modalities,⁵ and it appears that patients begin to eat more. Normalization of phosphorus without binders, as in the nocturnal dialysis literature, is achievable with increases in fluid volume and time per treatment.

Quality of life. Many physicians would argue that traditional in-center care provides a social experience for many patients, and I think that is true. Patients who control their own daily care, however, definitely feel better. Most striking is the time to recovery after therapy minutes versus hours for conventional HD. And when therapy is done at home on the patients own schedule, he or she gets the chance to take full advantage of the benefit the therapy brings.

Survival and hospitalization. The kidney care community has traditionally had challenges showing benefit in these measures because of comorbidities and a resulting need for enormous study sample sizes. However, I am very optimistic that benefits will soon be shown. Blagg published that daily dialysis in 117 patients was associated with a standardized mortality ratio (SMR) of 0.39,6 and NxStages unpublished internal data on survival with thousands of patients similarly indicates an SMR reduction of 40% or more, as well as a much higher transplantation frequency.

To further document daily therapy clinical outcomes, NxStage is conducting the FREEDOM Study, a 500 patient prospective observational study of daily therapy patients matched to 5,000 conventional dialysis patients drawn from the USRDS database. The primary endpoint of this study is annual hospitalization days; total costs of care, drug utilization, and quality of life are secondary endpoints. This study is approximately one-third enrolled as of the fourth quarter of 2007. Interim presentations of demographic and select secondary endpoint data will be released in 2008. We hope that other organizations will also contribute to the clinical knowledge base over time.

Moving forward

So what needs to happen for the resurgence to continue and for home HD to reach a percentage of patients that hits the radar screen? In my opinion, needs fall into three areas:

Simplicity and support. Although home HD technique survival is favorable versus PD therapy benchmarks, it can improve. Dropout is highest during the first three months due to the responsibilities of therapy on the patient and/or helper. Continuing to improve product ease-of-use and home training program support will help patients make it through this critical transition to home.

Physician awareness and support. Not surprisingly at this point in home HDs resurgence, a relatively small number of nephrologists are most active in prescribing the therapy to their patients. NxStage data suggests that over half of home dialysis patients are associated with less than 5% of practicing nephrologists. There is significant opportunity for greater physician involvement and awareness of the therapy.

Reimbursement. Over 85% of dialysis patients have Medicare as their primary payer, and Medicare's payment system has led to the predominantly in-center dialysis treatment regimen. You get what you pay for. Those with access today to home daily therapy disproportionately are commercially insured, and organizations like Kaiser Permanente have been at the forefront of expanding access to home hemodialysis. In particular, Medicare disincentives to home HD therapies in training reimbursement and in-center IV drugs as a profit center must be addressed.

Turning the corner on HHD

In summary, I believe that we are on the brink of a new era, with opportunities to achieve the improvements we had hoped to see in the HEMO and ADEMEX studies. We now have equipment that is patient-friendly and will be seeing more from industry. A growing number of nephrologists recognize the benefits of home daily therapy. And a motivated patient grapevine is proving to be a significant source of therapy candidates. Its just the beginning.
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Dr. Hull spent most of his nephrology career in the field of transplantation with Dallas Nephrology Associates, but treated his first hemodialysis patient in a home setting in 1968. He has consulted for a number of companies in the renal industry, and now serves as the senior medical advisor for NxStage Medical, based in Lawrence, Mass. He is a member of NNI's Emeritus Editorial Board.

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