Despite the higher prevalence of dialysis withdrawal and its significant association with death in ESRD patients, the phenomenon of dialysis withdrawal remains unclear [17]. There is a gap in the literature with regards to factors associated with dialysis withdrawal, mainly because of the scarcity of available literature and inconsistent findings across various studies [17].
The results of this study show that only 9.41% (n = 68) of patients have dialysis withdrawal. This finding is supported by Chan et al. (2012) who reported a 5-year incidence rate of dialysis withdrawal as 13.4% in Australia and New Zealand [6]. However, authors have also shown higher rates of dialysis withdrawal in other studies conducted in the US (24.9%) and Japan (31%). The difference between the study findings may be attributed to religion, cultural beliefs, and ethnicity, as these factors can also influence dialysis withdrawal [5,19,21].
We found the cardiac disease [p = 0.016] and hypertension [p = 0.019] were significantly associated with dialysis withdrawal. Comorbidities such as hypertension and cardiac disease are chronic diseases that gradually deteriorate patient health status, leading to complications that initiate a cascade of health issues [22]. These health issues increase the burden of disease and might lead patients to discontinue dialysis treatment. Similarly, Ellwood et al. (2013) and Fissell et al. (2005) found that vascular diseases and coronary artery disease were positively associated with dialysis withdrawal [7,14]; however, congestive heart failure [7,14] and other cardiovascular diseases were not associated with dialysis withdrawal [9].
The differences between the results in the present study with the previous studies [7,9,14] might be attributed to the definition of dialysis withdrawal. The present study defines dialysis withdrawal as “patient-elected withdrawal” vs. dialysis discontinuation due to any reason except recovery of kidney functions [7], unspecified dialysis termination and death [14], and all types of dialysis termination (by patient, family, physician or medical community [9]. Wetmore et al. (2017), defined the dialysis withdrawal as “patient elected discontinuation of dialysis” which is similar to our study. Their findings coincided with our present study findings: heart disease and hypertension increased the odds of dialysis withdrawal [18]. However, they did not explore mental health components (dementia, depression and bipolar disorder).
In the present study, dementia [p = 0.008] was found to be significantly associated with dialysis withdrawal. Irreversible neurologic impairment such as advanced irreversible dementia is one of the appropriate conditions for dialysis withdrawal [20]. Similarly, Kurella et al. (2006) [23] and Birmele et al. (2004) [9] found that dementia was associated with increased risk of death and dialysis withdrawal. However, the definition of dialysis withdrawal was not clear [23], and all types of dialysis termination, including a change in modality, death, and dialysis discontinuation was used as dialysis withdrawal [9] in these studies. Patients with comorbidities have a higher risk of mental health issues than patients without comorbidities [13,24]. Similarly, patients with mental conditions, such as depressive symptoms and dementia, have a higher incidence of comorbidities [25]. Because of this complex relationship, it is difficult to distinguish and understand the biologic plausibility between comorbid conditions and mental health issues in relation to dialysis withdrawal. This association between comorbid conditions and quality of life with dementia might be one reason for higher odds of dialysis withdrawal in patients with dementia, as was found in the present study.
The present study showed that age [AOR = 1.035; 95% CI = 1.012–1.058] was
significantly associated with dialysis withdrawal; an increase in age increases the odds of dialysis withdrawal. Authors have reported that older age is associated with a higher rate of dialysis withdrawal, which is similar to our findings [6,7,26]. Ellwood et al. (2013) found that increasing age was significantly associated with dialysis withdrawal [HR (Hazard Ratio) = 1.81; 95% CI = 1.75–1.88] [7]. Like the present study, Wetmore et al. (2017) define dialysis withdrawal as “patient and family elected discontinuation of dialysis” and showed higher odds of withdrawal in dialysis patients with age > 75 years [OR=1.61; 95% CI = 1.54-1.68] [18]. Older age patients have multiple comorbidities that are difficult to control, such as diabetes and hypertension that further debilitate with dialysis, leading to drastic deteriorations in physical and mental health and resulting in dialysis withdrawal [7,9,27].
Finally, the duration of dialysis [AOR = 0.999; 95% CI = 0.999–1.00], was significantly associated with dialysis withdrawal. Duration of dialysis might influence dialysis withdrawal, as patients with ESRD have chronic diseases and gradually deteriorate patient health status over time, which might lead to complications that initiate a cascade of health issues. These health issues increase the burden of disease and might lead patients to discontinue dialysis treatment [22,19]. Wetmore et al. (2017) have shown higher odds of withdrawal in patients with a longer duration of dialysis [18]. However, the odds of withdrawal in term of the duration of dialysis in this study was close to one [AOR = 0.99; 95% CI = 0.999–1.00], and hence not clinically meaningful. This might be because most of the patients had a shorter duration of receiving dialysis treatment, as the analysis was restricted to the last 5 years, including incident dialysis patients. Patients who have started dialysis prior to the start date of the study thus might ben on dialysis for more than five years, were not included in the study. It is important to note, however, that the results were based on the data from a regional renal program in Ontario, and it may be different from what is experienced in other dialysis population. Our study also showed that the duration of dialysis was not a factor that impacted the odds for withdrawal. It could be possible that other factors such as comorbidities and the quality of life deteriorate significantly over the long period of dialysis, which might have led to the dialysis withdrawal. In summary, our study didn’t indicate any influence of duration of dialysis on risk of dialysis withdrawal for a patient, given the other variables held constant.
Limitations
The main weakness of the study is the retrospective study design, which depends entirely on the quality and completeness of patient records. The quality of the dataset for this study was also dependent on the data quality of physician notes and data entry of the electronic patient record systems. However, a careful review of randomly selected patient records provided a limited level of assessment of the accuracy between the extracted data with the source system of patient records. There was limited information about the severity of mental health diseases in our population. The only information we were able to obtain was the presence or absence of mental health disease at the baseline (start of dialysis) and their association with dialysis withdrawal. Further comments about whether their dementia was later progressed into an advanced stage or remain the same (no change from baseline), when and how it was diagnosed and treated was not possible, due to study design and data limitations.
Furthermore, this study was unable to explore the relationship between financial burden, beliefs, and cultural and personal views in relation to the decision to withdraw treatment by either family or individual. However, the objective of the study was to identify factors at the start of dialysis between the two groups to identify the population at risk and early screening and intervention.
These limitations, though beyond the scope of the current study, are highly relevant for determining the factors that influence dialysis withdrawal. Being a single-center study, the generalizability of our study is also limited. However, consecutive sampling was performed to make the sample a better representation of a larger population. Due to the cross-sectional nature of our study, we are unable to comment on the causal association between identified factors with dialysis withdrawal.
Advancement of Knowledge and Application in Practice: Implications of the Study
Our findings were based on patient voluntarily refused dialysis treatment rather than patients who died or patients who likely faced imminent death and did not truly withdraw from the treatment, as withdrawal is commonly understood and reported in previous studies. The identified factors associated with voluntary withdrawal from the dialysis treatment will help understand what factors at the baseline (start of dialysis) that are associated with dialysis withdrawal. The findings will likely help clinicians and researchers develop a screening instrument by including the predictors identified in the study, such as cardiac disease, hypertension, and dementia, to identify patients with a higher risk of dialysis withdrawal at the time of enrolment. Some of these predictors are highly prevalent in the dialysis population. Intervention studies should develop models and instruments further include the severity of these predictors and how they affect withdrawal and assigning weights based on the severity of the disease. This instrument might also help clinical decision making and better engage patients in their care when the risk of dialysis withdrawal is discussed at the beginning of dialysis and throughout the entire treatment.
One of the most important findings was the identification of a mental health component for dialysis withdrawal, including dementia as one of the factors associated with dialysis withdrawal. KIDGO [20] mentioned irreversible neurologic impairment as one of the reasons for dialysis withdrawal. Renal Physicians Association has also provided many tools with acceptable psychometrics for assessment of mental health issues such as cognition, decision making capacity, depression, etc. in dialysis patients [28]. We measured mental health status (including dementia) at the start of dialysis. We assumed that dialysis patients with dementia were not at an advanced stage, as advanced irreversible neurologic impairment was one of the contraindications of dialysis initiation. The results showed dementia as a significant factor associated with dialysis withdrawal; highlighting that patients with dementia at the start of dialysis were more likely to withdrawal from the treatment than their peers without dementia. Due to the retrospective, cross-sectional nature of the study, we cannot infer whether the severity and stage of dementia progressed or remain the same for these patients and the use of mental health screening instruments and frequency of these assessments for these patients. In clinical practice, most dialysis programs screen patients for severe mental health issues prior to the enrollment of the dialysis program and potentially exclude patients with severe mental health conditions. This study identified a need for a modified mental health screening measure specific for dialysis patients, and the need for continuous monitoring of a patient’s mental health.
Lack of social support and mental health services might be one of the main barriers to the continuity of dialysis. These two components are highly interrelated since the lack of social support has a negative influence on mental health outcomes. However, due to the limited sample size and availability of data, we did not explore these topics in depth. To identify the mediators that influence the relationship between predictors, such as social support, mental health, quality of life, and dialysis withdrawal, future researchers should conduct studies with larger sample sizes, and qualitative exploration of the process.
In clinical practice, most dialysis programs screen patients for severe mental health issues before the enrollment of the dialysis program and potentially exclude patients with severe mental health conditions. This study identified a need for a modified mental health screening measure specific for dialysis patients, and the need for continuous monitoring of a patient’s mental health.