This study shows that many patients start hemodialysis despite choosing PD as their modality of choice, and only a minority of patients transition to PD. We found few predictors of this mismatch- age over 75 years, employment status and, to a degree, etiology of ESRD and, to a degree, non white race. Our study is unique in that it considers the initial dialysis modality choice by patient, not only the actual dialysis modality used.
Age over 75 years predicted an HD start in our cohort, even in those selecting PD. This finding correlates with USRDS data for Medicare Part D enrollees which show the incidence of PD start in those over 75 to be less than half that of younger patients 1
and with a study by Stack where patients starting PD were likely to be younger than those starting HD 9
. There are many potential reasons for this mismatch in elderly patients. Some physicians believe that elderly patients do not do as well on PD compared with HD10
. While this is supported by some (but not all) registry studies 11
, the only prospective study examining modality and outcome in elderly patients demonstrated no differences in mortality and quality of life 12, 13
. Medical and/or social contraindications are also important, and these will be discussed more fully below.
Employment status as a predictor of PD use has been previously reported. Stack found PD patients were more likely to be working full time compared with HD patients 9
. Being employed was also associated with PD use in a British 14
and a Taiwanese cohort 15
. In a qualitative study, 45% of new start PD patients cited the flexibility of treatment and the ability to continue working as a major factor in their modality decision, whereas none of the HD patients did so 16
The complex of the decision making process may explain why we did not find many predictors of the observed mismatch. Patient related, physician related and disease related factors may all contribute.
In terms of patient related factors, Finkelstein et al. reported that 35% of all CKD patients have very limited or no knowledge of their kidney disease 17
, and NHANES data showed that less than half of patients with advanced CKD are aware of it 18
. There are cognitive deficits associated with CKD 19–21
, and patients have commented they did not “catch on to” all of the options presented as they were “so sick at the time” 22
. As patients in our study waited over 40 weeks between the education and starting dialysis, it likely the some of the imparted information was not retained.
Patients initially choosing PD may simply change their mind over time. This study did not track whether patients initially choosing PD consciously decided against it prior to starting dialysis. This was likely for the 13 patients who started HD with an AV access already in place, and possible some of the remaining patients, as catheter start would be inevitable if patients changed their minds late in their disease course.
Family members may influence a patient’s modality decision 23
. A patient selecting PD may reverse this decision if they do not feel supported by family. Focus group data reveal that ESRD patients are concerned about the effects of dialysis on their family, and affirm the importance of family involvement in, and acceptance of, their modality choice 24
. In one study family members opinion was an important determination in modality selection for one half of incident PD patients 16
. We did not track whether patients had someone with them during the educational session. Having family present during the education session may serve two purposes. A “second pair of ears” may lead to better understanding and retention of the information presented, and family members present at the session may be able to vocalize their objections to a particular modality choice immediately, such that a patient who may have chosen PD if alone, will no longer do so with their family member(s) present.
Peer influence may also explain some of the discrepancy, as patients are influenced by other patients 22
. Hearing about a particularly good or bad experience with a particular dialysis modality after DME may cause patients to change their initial decision. Our data did not capture whether patients knew and/or sought input from current dialysis patients.
Provider opinion, especially that of the nephrologist, may influence patient choice of modality. Wuerth et al. found that almost 90% of patients felt their physician influenced their modality selection 16
. A patient initially enthusiastic about PD may be dissuaded if this decision is not supported by his or her nephrologist. Our patient population was referred for DME by 13 different nephrologists each with his or her own perspective on modality selection which undoubtedly influenced individual patients.
Physician opinion of a patient’s suitability for PD may lead to mismatch between chose and actual modality. Mendlesson et al. found 13% of all CKD patients were deemed medically ineligible for PD, by their provider 25
. This may be an overestimation of true ineligibility however, as several of the cited contraindications, including older age, multiple abdominal surgeries, and obesity are not university accepted as such 26–29
. Nonetheless, perceived, rather than absolute medical contraindications are important, as these perceptions may lead some physicians to discourage PD for a patient who is able use this modality.
Social barriers to PD use are somewhat more common than medical contraindications, with 17% of CKD patients being deemed socially ineligible for PD 25
. Again, this may be an overestimation as some of the barriers cited may not be true barriers at all (such as age), or may be overcome with intense family support or assisted PD (such as the inability to due PD by oneself, compliance issues and cognitive issues) 30
. However, as above, the existence of one of these factors may be enough for a nephrologist to abandon PD as a viable option despite a patient’s selection of this modality.
With the exception of the two patients excluded at the outset, our study did not examine the role of medical and social barriers (perceived or real) to the use of PD, especially those developing between time of education and dialysis start. Certainly this may have contributed to the observed mismatch between chosen and actual modality, particularly in the elderly in whom these contraindications are more prevalent.
Disease related factors are another potential contributor to modality mismatch. In our study 57% of the patients choosing PD but starting HD started in the hospital, the vast majority with central venous catheters The large number of unplanned, urgent dialysis starts in our population is concerning, and although not necessarily so, it is likely that many of these patients had either a rapid progression of CKD or a superimposed acute event requiring an urgent, hospital based start. Separating out which of these patients truly had an unforeseeable event requiring emergent RRT start from those who “fell through the cracks” is important, as the latter may be amenable to specific interventions designed to enhance follow up whereas the former would not.
Finally, factors specific to the educational session itself may have some bearing on initial dialysis modality. There is no consensus on the best way to educate CKD patients, and it is conceivable that the method used in our institution is not optimal. There was an attempt to contact patients after three months to follow up, but it is not clear how often this contact was successful. The vast majority of patients did not have return visits for education, and although they were encouraged to call with questions, only approximately 10% did so. All education done for this cohort was completed prior to the institution of the Medicare Improvement for Patients and Providers Act, which funds up to six educational sessions of CKD. It is possible that with multiple educational sessions many of the potential issues discussed above could have been identified and modality selection modified, if appropriate.
Our study has several strengths. Tracking patients from modality selection to start of dialysis provides a starting point for future interventional strategies, and provides baseline data against which we may gauge their success. Also, our follow up was complete, in that all of the patients started dialysis in our catchment area.
There are several limitations of this study. Our cohort was small in size and is a single centered such that our findings may not be applicable to other institutions or practices due to differences in patient demographics, provider opinion on optimal dialysis modality and structure of the pre-ESRD education program.
Our analysis was limited to those variables which could be extracted from our dataset, namely quantitative metrics. For a complex decision such as dialysis modality selection, there are factors involved which are not accessible via a quantitative approach. Previous studies using focus groups and patient interviews have identified qualitative considerations, including flexibility of schedule, privacy considerations, the ability to continue working, and effects of the modality on the family 16, 23, 24
. These were not explored in this study.
In conclusion, over half the patients who choose PD start dialysis with HD, many of them urgently. We found that age over 75, and employment status predicts starting with HD when PD is chosen, and age over 75 and a non glomerular etiology of ESRD predict HD use day 91. These findings help define a group who should be carefully monitored to ensure they start PD, if this remains their modality choice. Closer examination of the events occurring between education and dialysis start is needed to determine the root cause of HD starts in those choosing PD, paying particular attention to the development of medical/social contraindications, superimposed acute kidney injury or rapid progression of CKD and losses to follow up in patients with established nephrology care. Qualitative analysis of this decision making process looking at factors such as family support and conscious change of modality choice is also warranted.