Cost of Dialysis Therapy by Modality in Manitoba

Discussion

This cost-minimization analysis provides a comprehensive examination of the training and annual maintenance costs of each dialysis modality available to patients with end stage kidney failure in Canada and a tool with which they might be compared. In keeping with previous cost analyses (30–32), this study affirms a considerable cost saving related to home dialysis modalities over in-center HD provided that a sufficiently long period of dialysis is expected. Building on these previous analyses, we compare the costs of the NxStage System One with other available dialysis modalities.

The model also provides a specific minimum period over which the initial cost of training a patient may be recovered, and this period may be determined using specific regional characteristics. Lastly, a contemporary reanalysis of the required costs of dialysis therapy can help provide accurate assessments of costs to the health care payer in the current marketplace, accounting for temporal changes in prices for dialysis-related consumables (e.g., PD supplies and erythropoietin) as well as the expanding size of many home HD programs.

Selecting a modality on the basis of a patient’s estimated time on dialysis allows for treatment costs to be minimized. Regarding HD modalities, patients with the shortest expected duration of treatment should be considered for in-center HD, whereas placing those with the longest expected duration of treatment on conventional home HD will minimize costs. An intermediate expected duration should be optimally addressed using the NxStage System One, which although costing 36% more for consumables, has a 39% lower cost associated with training.

There are multiple different modalities for home dialysis, and in each modality, there are differing platforms. Each of these is characterized by a different spectrum of advantages and disadvantages. For example, patients with space constraints may prefer a modality that minimizes or avoids modifications to the home, such as home water filtration systems or space requirements for storing dialysis-related supplies. In addition, there may be financial, electrical, water supply, plumbing, or waste disposal concerns that influence modality choice (33). Further consideration should also be given to the technical knowledge required for using and maintaining the dialysis machine, wherein a tradeoff of cost for ease of use could be considered reasonable if it can contribute to patient uptake or retention (34). Relative ease of shipping supplies for patients may also be important, especially with respect to remote locations with expensive logistics requirements (35). Ultimately, these factors and others should help guide the decision to recommend patients for home therapy and the specific choice of modality.

Consideration must also be given to the clinical and cost implications of switching patients from one dialysis modality to another. Unfortunately, because of the difficulty of conducting a randomized, controlled trial comparing self-care home dialysis with full-care in-center dialysis, much of the evidence for comparative effectiveness relies on observational studies that have a high risk of selection bias. With the inability to completely rule out residual confounding, these findings should be interpreted cautiously, and per capita costs associated with shifting a part of the patient population from one modality to another may indeed differ from the existing cohort given varying baseline characteristics. Notwithstanding, after adjustment for patient characteristics, many studies have found no higher risk of mortality among patients receiving home dialysis (PD or HD) in comparison with in-center HD (36–38). In addition, evidence suggests that there is no additional risk of all-cause hospitalization in the home dialysis group (39). The risk of technique failure is also important, because it is associated with adverse outcomes and increased costs, and it can result in a cost-ineffective treatment choice if a patient does not remain on a home therapy long enough to justify the cost of training and setup (40).

Program size may also be an important factor to consider in evaluating the costs of home HD programs. The prevalence of home HD in Canada totaled 4.8% in 2014, having almost doubled since 2005 (13). Because many home dialysis programs are still in their early stages and may not have achieved optimal operational efficiency, consideration of how fixed costs adapt to changing program sizes for home programs would be prudent. Moreover, in larger dialysis programs, it may seem more favorable to introduce home HD programs, because economies of scale could be achieved quicker and the startup costs of a program would represent a smaller fraction of overall capital costs (41). Data provided by this model should be interpreted with this in mind, and the reader should recognize that newer and/or smaller programs may experience some per capita cost differences compared with those presented herein.

Many patients are not suitable to perform full self-care dialysis in the home, and as such, consideration of introducing fully or partially assisted home PD and home HD programs may be a cost-saving strategy, particularly with an aging dialysis population. However, the preferred method of administering these programs is unclear; some care models may prefer the use of registered nurses for more complex patients, whereas other models could be considered for patients with simpler cases, providing opportunity for improved resource use (42). It may also be worth evaluating the potential synergies of supporting assisted dialysis resources in other areas of the health system that interact with a relatively high number of patients on dialysis, such as long-term care or personal care home services (43). Several studies have considered the potential benefits of these assisted dialysis programs (43,44), but a more thorough analysis of the costs of various assisted home dialysis staffing models is warranted.

Our model has many strengths. First, the activity-based human resources model is on the basis of figures generated from actual program expenditures, and the estimated expenditures are validated against data from a different region and time period. This strongly supports the model’s generalizability to other publically funded jurisdictions, especially in Canada and likely in other publicly administered systems, such as Australia and the United Kingdom. Second, all equipment and supply costs represent actual expenditures provided by statements of operations from the Manitoba Renal Program and accurately reflect the differences in supply requirements between dialysis departments.

The most important limitation of the model is a product of its perspective. In considering costs applicable to the public payer, those costs borne by the patients and their caregivers are not factored into this model. The estimates provided account for public health care costs related specifically to dialysis therapy directly and do not account for the total cost of caring for these patients; they exclude transportation, caregiver costs or assistance with activities of daily living, access costs, patient opportunity costs, and other items. Access costs maybe higher with more frequent dialysis, regardless of whether it is delivered in center or at home, and daily dialysis prescriptions could increase these costs preferentially for home modalities (45). Heterogeneity should also be recognized between programs: data used to estimate consumables costs are generated from the Manitoba Renal Program, and the reader is reminded that the unit costs and quantities may vary between institutions on the basis of local supplier arrangements and patient mix. As well, differences may exist between modalities for items not accounted for in the model, such as vascular and PD access costs. In addition, although capital costs in the presented model are easily adjustable to local costing using the provided tools, this accommodates for differences in construction costs for comparable units and does not accommodate for units with differing forms or standards. Lastly, validation of costs determined with the activity-based model against the home HD program was difficult to interpret due to a recent trend of transferring patients between conventional and NxStage System One machines, incurring atypical human resource expenses for training and education.

In summary, all forms of dialysis are associated with substantial use of health care resources. Home modalities (home HD and PD) have lower overall maintenance costs, and beyond a short time horizon, they are more cost efficient when including incremental training expenses.