Comparing survival between home hemodialysis and peritoneal dialysis—is the controversy over?

Globally, home dialysis remains very underutilized in many parts of the world: only limited countries such as Hong Kong, Thailand, Mexico, Canada, the Netherlands, Iceland, Finland, Denmark, Australia and New Zealand utilize home dialysis in over 20% of the dialysis population [1]. In most high and middle-income countries, home dialysis is generally more cost-saving than in-center dialysis [2]. However, cost calculations for in-center and home dialysis are complex and comparisons may vary between countries. Several previous studies compared patient survival between hemodialysis (HD) and peritoneal dialysis (PD), but these studies were generally non-randomized [3–8] as randomizing patients by their dialysis modalities proved to be difficult [9]. As a result, these studies generally suffered from bias inherent to the choice of dialysis modalities. Some studies used a matched cohort analysis and observed survival advantage with home HD (30–40% higher) compared with PD [4, 5, 8] but there could be residual confounding not captured by the analysis. On the other hand, there was suggestion from the New Zealand home dialysis program that patients receiving PD may enjoy better survival within the first 3 years, after which PD was associated with 33% higher mortality risk than home HD [3]. The discussion of survival outcomes among different dialysis modalities is important for healthcare professionals and other stakeholders involved in kidney failure care and also for patients who receive these dialysis modalities. In recent years, there is a global advocacy from many kidney organizations to promote global policy and practice changes to increase the accessibility and adoption of home dialysis [10, 11]. The current coronavirus disease 2019 (COVID-19) pandemic further encourages more utilization of home dialysis therapies as it enables patients to carry out their dialysis treatment at home, minimizing their need to travel to hospitals or dialysis centers for in-center dialysis, and may thus reduce the risk of COVID-19 infections [12]. The comparison of COVID-19 incidence between patients undergoing in-center HD versus home dialysis has to be interpreted with caution as patients undergoing in-center HD would likely undergo more screening than those on home therapies. Nevertheless, data from the United States Renal Data System (USRDS) showed that the COVID-19 hospitalization rate was 3 to 4 times higher for patients doing in-center HD compared with those receiving home PD or HD [13]. Patients receiving in-center dialysis were also three times more likely to test positive for COVID-19 than patients receiving home dialysis [14, 15]. This adds further incentives to promote uptake and growth of home dialysis worldwide. Furthermore, home dialysis is associated with lower overall costs, better patient quality of life and allows more flexibility and free time for patients’ life participation compared with in-center dialysis. In September 2021, a new bipartisan legislation was passed in the USA that aims to make home dialysis more accessible and affordable to kidney patients. In their study, Bitar and co-workers [16] analyzed all adult subjects who started kidney replacement therapy (KRT) between 2004 and 2017 (n = 536) in Finland in the district of Helsinki-Uusimaa. The study was not randomized. Subjects who were on home dialysis modalities at 90 days from starting KRT were included in the analysis. Survival of patients on home HD, automated peritoneal dialysis (APD) and continuous ambulatory peritoneal dialysis (CAPD) were compared using an intention-to-treat approach. Of note is the infrastructure of Finland's medical provision system, which adopts a ‘home-dialysis first’ policy, allows a free choice of home dialysis modality and uses a multidisciplinary care approach with a well-developed training network to promote home therapies. The multidisciplinary team provides patients with pre-dialysis education of different dialysis modalities options equally, with lectures and on-the-spot information resulting in a much higher rate of patients choosing a home dialysis therapy [17, 18]. Furthermore, the medical team evaluate patients for any contraindications and suitability for various modalities and inform the patients. If there are no medical contraindications, patients could choose the modality that they find most suitable for themselves taking into consideration their work life, social situation, lifestyle and hobbies, etc. This multidisciplinary care model adopted in Finland is an ideal kidney failure care reference for the rest of the world, and is well in keeping with the conclusions from Kidney Disease: Improving Global Outcomes (KDIGO) controversies conference on dialysis initiation, modality choice, access, and prescription to adopt a personalized care approach with ‘shared decision-making’ to enable patients to decide the most suitable dialysis modality for themselves, taking into consideration their preferences, lifestyle, social circumstances and life goals [19]. The study evaluated the real-life situation when incident patients can freely make their home dialysis modality choices after receiving pre-dialysis education and examined the outcomes associated with their modality choices. The study was also unique in differentiating the type of home PD therapies, and compared home HD versus APD and CAPD separately. The study, however, did not include assessment of caretaker burden or burden of home therapy for the patient, both of which may impact patients and their caregivers. Notably, the 5-year survival probability was 90% for home HD, 88% for APD (mean age of patients was 50) and 56% for CAPD (mean age of patients was 65). After adjusting for propensity scores, the mortality hazard ratio (HR) was 1.1 [95% confidence intervals (CI), 0.52–2.4)] for APD and 1.6 (95% CI, 0.74–3.6) for CAPD compared with home HD. They did propensity score analysis and noted the clinical, biochemical characteristics and comorbidities of patients choosing home HD at start of dialysis were very comparable to those choosing APD, and patient survival outcomes with these two modalities were also very comparable. On the other hand, patients who chose CAPD therapy had much higher median age and more comorbidities, and survival of these patients was inferior to those receiving home HD or APD. The difference in outcomes became statistically insignificant after adjusting for confounders, suggesting that the worse survival with CAPD may be attributed to the more aging population with more comorbidities among those who chose CAPD, and not to the modality itself. The relatively young age of home dialysis patients may account for the excellent outcomes seen in this group of patients. The analysis censored patients at the time of kidney transplantation or at transfer to in-center HD but this did not change the results. What do these data imply? Do we need another randomized trial of dialysis modality to inform clinical practice on modality choice? Given that the choice of home dialysis modality should be personalized with shared decision-making taking into consideration patients’ preference, clinical and social circumstances and life goals, a clinically more important question to address would be: how should we personalize the choice of home dialysis modality? Which home dialysis modality (HD, APD or CAPD) would best suit individual patients’ characteristics and enable patients to maximize their life goals and quality of life. Clearly, giving a free modality choice is associated with more satisfaction of patients with their care. It is also equally important that for patients choosing home dialysis, appropriate support and transfer back to in-center dialysis is available, when necessary, for example, due to physical exhaustion, complication or burden of caretaker for those requiring assisted home dialysis. APD has the advantage of allowing patients more daytime freedom, more flexible adjustment of prescription regimen and allows an increase in cycle frequency and exchange volume in an automated fashion without burdening patients with more manual exchanges than CAPD. However, it is more costly than CAPD and requires more technical skills for patients or caregivers, and may not be a readily feasible option in cost-constrained settings or in elderly subjects who do not have caregivers’ support. Likewise, home HD also enables patients to have more flexibility with performing their HD sessions and adjustment of their prescription. Both modalities tend to select outpatients who are younger, more educated, clinically and physically more fit and technically more capable. There are some suggestions that patients receiving home dialysis may be associated with better health-related quality of life (HRQOL) measures compared with those on in-center HD, although randomized studies were very limited [20–22]. It is essential that healthcare professionals provide thorough and unbiased patient education for the different dialysis modalities in terms of overall survival and quality of life measures so as to facilitate patients choosing the modality that best suits their needs, lifestyle and characteristics, as what matter most to patients are living and functioning well on dialysis rather than simply surviving. This study is important in demonstrating that there is no ‘one size fits all’ in the choice of home dialysis modalities. An individualized person-centered care approach that incorporates patient preferences, needs, lifestyle and goals while maintaining best practices for quality and safety should be adopted in all patients requiring dialysis treatment and choosing their modalities. The finding that patients choosing home HD and APD have similar 5-year survival outcomes will be useful for patients’ consideration when choosing their home dialysis modality.