Choice of Dialysis Modality in the United StatesKirsten L. Johansen, MD
Arch Intern Med. Published online September 27, 2010. doi:10.1001/archinternmed.2010.370
Over 100 000 patients started dialysis in 2007, the most recent year for which data are available.1 Although kidney transplantation is considered the best choice for renal replacement therapy on the basis of survival and quality of life, many patients are not eligible for transplantation. This factor, plus a shortage of available organs, means that many patients with end-stage renal disease (ESRD) undergo prolonged dialysis therapy. Most patients who need renal replacement therapy start on some form of dialysis, either hemodialysis (HD), usually performed in-center 3 times per week, or peritoneal dialysis (PD), usually done by the patient at home. Which modality is preferable, and for which patients, has been the subject of controversy since the inception of PD in the 1970s.
About 1% of Medicare beneficiaries have ESRD, but these individuals account for 5.8% of the total Medicare budget, or $24 billion as of 2007.1 Although the profitability of PD relative to HD for health care providers is complex and changing, several comparisons have shown that PD is less expensive than HD on a per-patient per-year basis, with the difference estimated to be approximately $19 000 based on 2005 Medicare data.2 Despite its lower cost, PD utilization in the United States has declined steadily from a high of 14.4% of the dialysis population in 1995 to a low of 7.1% in 2007,1 and the decline in number of new patients starting PD began even earlier. This decline in PD utilization raises a number of questions: Is declining use of PD appropriate? Who or what is driving this trend? Two articles in this issue of the Archives address different aspects of this issue.3-4
SURVIVAL AND QUALITY OF LIFE
The study by Mehrotra et al3 addresses the question of possible differences in survival among patients starting HD or PD. Because patients starting PD are usually younger, healthier, and more likely to be employed than patients starting HD, and because there are no large randomized trials, survival differences have been difficult to evaluate. Studies using registry data have suggested that younger patients and those without diabetes or congestive heart failure (CHF) might benefit from PD, especially in the first 2 years, but that older patients with diabetes or CHF do not fare as well on PD.5 Mehrotra and colleagues3 examined survival differences among patients started on HD or PD across 3 time periods and found that survival on PD has improved relative to survival on HD from the 1996-1998 to 2002-2004 periods, so that in the most modern era, survival was not different among patients starting PD or HD. Younger and healthier patients still did better on PD than older patients with comorbidities, but only older patients with diabetes and at least 1 other comorbidity had higher mortality on PD than HD, and this difference was driven by differences that occur later in the course of treatment (beyond 2 years). The authors concluded that the equivalent outcomes of the 2 therapies, in conjunction with the lower cost of PD, would support greater utilization of PD in the United States, although they acknowledged the possibility that more selective assignment to PD over the last decade could have contributed to the improved outcomes. Nevertheless, it does not appear that survival differences between PD and HD would warrant the major reductions in the use of PD that have occurred.
Although equivalent survival of patients choosing both dialysis modalities is a matter of considerable importance to physicians discussing modality selection, survival does not seem to be a major factor in patients' decisions about dialysis modality.6 Rather, patients' choices appear to be driven by issues related to autonomy, scheduling, and maintaining their current lifestyle. Indeed, PD allows patients considerably more autonomy, which many patients find attractive. However, with autonomy comes the responsibility for performing the dialysis on a daily basis, which some patients find onerous, preferring to have regularly scheduled dialysis performed by health care providers. Patients starting PD have been reported to have higher health-related quality of life (HRQOL) than patients starting HD in several domains.7 However, HRQOL scores after 1 year were not significantly different among PD patients and HD patients after adjusting for differences in patient characteristics and for baseline scores, except for effects on daily life, which was better among PD patients. Despite substantially similar HRQOL, PD patients reported greater satisfaction with care and staff encouragement.7-8
DISCUSSIONS WITH PATIENTS ABOUT THE PD OPTION
So, if HRQOL is similar between the 2 modalities and patient satisfaction is greater on PD, why are health care providers not recommending PD to all of their patients and why do so few patients choose PD? A prerequisite for patients to make informed decisions is that treatment options be discussed with them. Unfortunately, this is by no means a given. In a national study of incident dialysis patients in the 1996-1997 period, only 25% of patients initiating HD reported that PD had been discussed with them before they started treatment for kidney failure.9
Similarly, Mehrotra et al10 found that only 34% of new dialysis patients in southern California in 2002 had been presented with PD as an option. Presentation of PD as a treatment option and the time spent on patient education were the only variables significantly associated with initiation of PD. The authors noted that patients with whom PD was discussed as an option were somewhat healthier (ie, had higher hemoglobin concentrations and were more likely to be ambulatory) and more likely to be employed but that most patients did not have contraindications to PD.
A study specifically examining the prevalence of contraindications to PD among patients starting dialysis in several centers in the United States and Canada found that there was variability across centers in the percentage of patients deemed eligible for PD but that the overall percentage was fairly high at 78%.11 A single-center study estimated that approximately half of the patients who are offered PD actually choose this option.12
The data available so far have led experts to conclude that low PD utilization is, at least in part, the fault of nephrologists, who are not discussing PD options with patients, possibly owing to concern about higher mortality (addressed by Mehrotra et al3), inadequate training of nephrologists, nephrologists' bias against PD, pressures to fill HD chairs, late referral to nephrologists, and other reasons. As far as training of nephrology fellows is concerned, there is wide variation in the number of PD patients available to fellows during their training and in the amount of time fellows spend providing care to patients on PD. A report from 2002 found that 29% of US nephrology training programs had fewer than 5 PD patients per fellow, and that fellows spent less than 5% of their time receiving training in the care of PD patients in 14% of programs.13 Given that the prevalence of PD has declined even since this report, we may be in the midst of a vicious cycle whereby physicians feel inadequately prepared to provide care for PD patients, thus further reducing the use of PD and training opportunities.14 Although it is difficult to assess nephrologists' potential bias, when practicing nephrologists were asked about the optimal distribution of dialysis modality to provide patients with maximum survival, wellness, and quality of life, a form of PD was recommended in 33% of cases.15 This suggests that nephrologists are not the only barrier to initiation of PD, since rates of PD initiation fall far below this level.
The article by Kutner et al4 in this issue of the Archives adds important new information to this debate. In the Comprehensive Dialysis Study (CDS),16 a more modern cohort of incident patients beginning dialysis in the 2005-2007 period, 61% of patients reported that PD had been discussed with them before the start of dialysis. Although discussion of PD would be expected to be somewhat higher in the CDS than in the general incident dialysis population because participants were somewhat healthier,4, 16 these results suggest that rates of discussion of PD have increased as incidence of PD has declined. Another striking finding of the CDS was that only 11% of patients informed about PD as an option actually chose this modality, far below the 50% that had been previously reported. Low rates of adoption of PD among informed patients in the CDS are likely a function of patient characteristics and of the quality and quantity of information presented. In other words, it seems that nephrologists are discussing PD as an option with more patients, but they may not be doing a very good job at it. Unfortunately, this study did not address the issue of the time spent discussing PD or of the quality of the information. Nevertheless, the CDS may serve as an important benchmark to gauge changes in patient modality selection as a result of new policies to address the issue of inadequate discussion of treatment options for ESRD. The Center for Medicare Services added a new Medicare benefit, effective January 1, 2010, that provides patients with stage 4 chronic kidney disease coverage for up to 6 sessions and explains their treatment options, including PD.17 It will be important to track whether this benefit results in improved quality and quantity of transmission of information to patients and whether increased efforts to provide education and reassuring new information about survival among patients starting PD3 will be able to reverse the trend of declining PD use in the United States. Current data suggest that increasing PD utilization would be cost-effective and would have the potential to increase dialysis patients' satisfaction with care without compromising survival.
AUTHOR INFORMATION
Correspondence: Dr Johansen, San Francisco Veterans Affairs Medical Center, Nephrology Section 111J, 4150 Clement St, San Francisco, CA 94121 (Kirsten.johansen@ucsf.edu).
Published Online: September 27, 2010. doi:10.1001/archinternmed.2010.370
Financial Disclosure: None reported.
Author Affiliations: Division of Nephrology, University of California San Francisco, and Nephrology Section, San Francisco Veterans Affairs Medical Center, San Francisco, California.
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http://archinte.ama-assn.org/cgi/content/full/archinternmed.2010.370