Attitudes of British Isles nephrologists towards dialysis modality selection: a questionnaire study

Sarbjit Vanita Jassal1,2,, Ganesh Krishna2, Netar P. Mallick3 and David C. Mendelssohn1

1 Division of Nephrology, University of Toronto, Toronto, Canada, 2 Faculty of Medicine, University of Liverpool, Liverpool, UK and 3 Department of Nephrology, University of Manchester, Manchester, UK



   Abstract
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 
Background. Dialysis demographics are changing around the world. Within the UK a striking decrease in the overall use of peritoneal dialysis (PD) has been noted. We set out to determine the opinions and attitudes of British Isles nephrologists about dialysis modality decisions and optimal dialysis system design.

Methods. A survey questionnaire was mailed to a random selection of members of the Renal Association of Great Britain and Ireland.

Results. A 63% response rate was achieved. Decisions about dialysis modality were based mostly on patient preference (mean score 4.4 on a scale of 1–5), quality of life data (mean score 3.8), and morbidity and mortality data (mean scores for both 3.6). The least important factors when choosing the modality of dialysis care were the treatment costs to either the patient or the health care system. Respondents felt that both PD and hospital-based haemodialysis (HD) were over-utilized in today's practice. They suggested that an ‘ideal dialysis system’ (based on patient survival, wellness, and quality of life) should have 27% of patients dialysed using hospital-based HD, 24% in a satellite unit, 11% dialysed using home HD, and 38% on some form of PD (19, 16, and 3% for CAPD, automated PD and intermittent PD, respectively). Few differences were identified between an ideal system which optimized patient survival, wellness, and quality of life, compared with one which optimized cost-effectiveness.

Conclusion. This survey suggests that most nephrologists in the British Isles feel that hospital-based HD and CAPD are being currently overused, and that future dialysis planning should include a higher proportion of patients on satellite dialysis, home HD, and automated PD to optimize both dialysis cost-effectiveness and patient outcomes.

Keywords: haemodialysis; modality; selection peritoneal dialysis



   Introduction
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 
A dialysis shortage, involving mainly haemodialysis (HD) capacity, is being recognized throughout the world. Long-term registry cohort studies comparing HD and peritoneal dialysis (PD) appear to suggest equal mortality and morbidity profiles, but are limited in their analysis by confounding factors such as frequent modality switches and the criteria used for patient selection [14]. By world standards, the UK has relatively high PD utilization, although it has fallen to a level of around 40% recently [5] from about 50% of the prevalent modality mix in the early 1990s. Critics in the UK believe that PD selection is often made with no choice and in circumstances where there is a high risk of PD failure. With tightly controlled resources, the option to convert a patient from PD to HD is often influenced by the availability of HD ‘slots’, leading to waiting lists for patients needing to switch modality.

Government and health service trusts often focus on cost containment when planning future resource allocation. Consequently, many authorities favour the expansion of less costly PD services with a relative reduction in HD services, potentially worsening the problem. Our objective was to establish the criteria used to select dialysis modality, and to compare what British Isles nephrologists perceived as an ‘ideal’ modality distribution with the services available to them at present.

The study objectives were as follows.

(i) To identify the most important factors influencing modality selection.
(ii) To identify the optimal mix of dialytic modalities.
(iii) To compare the results with those from similar surveys in Canada and the US.



   Subjects and methods
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 
The Renal Association of Great Britain and Ireland (RAGBI) is a 612-member strong association for nephrologists and clinicians involved with renal disease. A total of 210 participants were randomly selected from the membership list of the RAGBI. Members not resident in the British Isles were automatically excluded prior to the random selection process. The questionnaire was mailed to all participants in May and June 1999. A second mailing was sent to non-responders after 6 weeks to encourage a higher response rate.

The survey questionnaire (available from the authors on request) contained 72 questions, and was based upon a previous survey questionnaire of US and Canadian nephrologists. The questionnaire was modified by removing questions relating to facility reimbursement and by correcting phrases and spelling so as to be more appropriate for a British Isles population. The questionnaire was designed to identify what was perceived as an optimal dialysis modality mix, to survey factors influencing current modality selection, and to elicit opinions about the current local distribution of dialysis facilities. At the time of the survey, daily dialysis and nocturnal dialysis methods were not commonly in use, and it was felt that there was insufficient experience for an informed view; questions were therefore not directed at either of these two modalities. Demographic details requested included age, gender, year of commencing practice, region, and type of practice (District General Hospital, University Hospital or other).

The following definitions were used.

• Hospital-based HD was defined as conducted in a nurse/doctor-supervised unit attached to a hospital whose facilities were available as needed. This form of treatment is particularly suitable for patients who are clinically unstable, physically frail, or who are being established on dialysis.
• Satellite HD was defined as a unit where dialysis facilities were provided in a purpose-designed unit, unattached to a large hospital, with our without medical staff available on site. Patients dialysed in such facilities need to be clinically stable with a degree of physical independence. Many participate actively in setting up and monitoring their dialysis procedure.
Data storage and analysis were conducted using Microsoft Access Database (Microsoft Office 97) and SPSS-PC v 9.0. Simple descriptive statistics were applied to the data. In cases where the data were skewed, descriptive statistics were reported using mode, median, and quartiles. Approval from the Renal Association of Great Britain and Ireland Clinical Trials Unit and the local hospital ethics board were obtained.



   Results
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 
Respondent characteristics
One hundred and thirty two respondents replied (63%). Of those who replied, 24 were excluded because they were either in non-clinical practice (16 of 24) or retired (eight of 24) at the time of the survey. Of the remaining 108 subjects, the mean age was 43 years (range 26–66 years) with a 73% male preponderance. Most survey respondents were white (88%), had a mean practice experience of 20 years and were involved predominantly with dialysis care. Most nephrologists were based in an academic unit or in a District General Hospital (DGH) (68 and 28%, respectively). Univariate analysis showed no difference between the characteristics of academic nephrologists from those who were based in a DGH. All regions of the British Isles were represented, with a higher number of participants in areas of higher population (for example in Thames region and south-west and north-east England there were 24, 15, 15 respondents, respectively).

Current practices
The factors most important in the selection of dialysis modality were scored on a linear scale of 1–5 (1=not at all important, 5=extremely important). Patient preference was ranked as extremely important; quality of life data, morbidity, and survival data were also quite important factors (Table 1Go) while costs both to patients and the health care system were considered only moderately important. Comorbid conditions were, as expected, important in the decision-making, but only the presence of heart disease tended to make more physicians chose PD over HD (52% favoured PD, 43% felt either was appropriate, 5% favoured HD). Social factors favouring PD included the need for a flexible lifestyle and distance more than 50 km from the dialysis centre. Participants were asked the ideal body weight above which PD should generally not be considered; although responses covered a wide spectrum, they mostly followed a bimodal pattern, with more than 30% using an ideal body weight cut-off of 90–100 kg and a further 29% who believed there was no upper body weight cut-off.


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Table 1.  Factors considered of importance by nephrologists in dialysis modality decision-making process

 
Medical factors were often important in the selection of one modality over the other, with a greater tendency to favour HD. However, PD was favoured over HD in patients with heart disease by over 52% of nephrologists, and in diabetic patients by 33%. In the overall analysis, age, body image, and the presence of lumbar pathology or large body habitus did not influence modality selection. Issues relating to social needs, such as employment, lifestyle flexibility, and the ability to have a more liberal diet, promoted the use of PD over HD (Table 2Go).


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Table 2.  Factors influencing dialysis modality selection (not all values add up to 100% because of missing values)

 

Ideal dialysis practice
To establish what dialysis modalities would be most optimally sought, we asked whether the current relative use of each of six different dialysis modalities was under-utilized, over-utilized, or about correct. Of those who replied, 34% felt continuous ambulatory PD was over-utilized, whereas 60% felt automated PD was under-utilized in their unit. With respect to hospital-based HD, 35% felt it was over-utilized, whereas 46 and 66% felt satellite and home HD was under-utilized. To further establish preferences in current dialysis planning, nephrologists were asked to design a typical dialysis system to maximize survival, wellness, and quality of life; or, in a second question, to maximize cost effectiveness. Using this hypothetical scenario, nephrologists allocated a mean of 62% of places to HD to maximize survival, wellness, and quality of life and 56% to maximize cost-effectiveness (Table 3Go).


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Table 3.  Allocation of places to each of six dialysis modalities in order to maximize outcomes in an ideal dialysis system

 

Comparison with other countries
The data showed no differences when compared with similar surveys in the US and in Canada (data not shown). Clinical decisions in all three countries were based on patient preference, with lesser emphasis placed on morbidity, mortality, and quality of life data. Clinical features leading to a preference for one dialysis modality over the other were also similar, with minor differences in the rankings. Similarly, all groups recommended an increase in satellite and home HD, an increase in the usage of automated PD, and a similar distribution of modalities in an optimized system.



   Discussion
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 
The decision of whether to treat a patient with HD or PD is often made using implicit criteria. Furthermore, the argument about whether HD is superior to PD, or vice versa, still continues, with the literature showing conflicting results [1,68]. With the exception of active abdominal disease, few conditions should preclude the use of either modality [9].

In this paper we set out to survey the attitudes of UK nephrologists towards dialysis modality selection. Our objective was to establish if medical or personal factors were most important, and if there were clear indications for the preferential use of one modality over the other.

The data presented here make four important points. First, patient preference is of most importance in modality selection, with lesser emphasis being placed on mortality and morbidity. Secondly, it is of interest that 36% of the respondents felt that hospital HD and CAPD are over-utilized, and advocate increased use of home and satellite HD and automated PD. Thirdly, UK nephrologists believe that an optimal modality distribution includes about 40% PD. This is quite similar to what is presently the case, and suggests that those who fear that there is still an over-reliance on PD are overstating the case.

Fourthly, and perhaps most importantly, we note that there is little difference seen in the attitudes of nephrologists towards modality selection and distribution across a sample of different countries—British Isles, Canada, and the US. The nature of the health care system in the three countries is very different, as is PD utilization in Canada (29.6% in 1997) and the USA (12% in 1998) [10,11]. All three groups suggest that patient preference is by far the most important factor to be considered when selecting a modality, and all place similar weight on the medical and social issues explored [12,13]. All three groups agree that PD should ideally comprise about 30–40% of the modality mix, and agree that more community-based and home HD, as well as more cycling PD, ought to be encouraged. This suggests that nephrologists are highly sensitive to patient preferences and patient outcomes, despite the discordant medical systems observed in the three nations. The similarity of results suggests that nephrologist opinion is not the dominant factor in determining actual ESRD modality distribution. These results support our previous conclusions that unknown but important factors external to the physician may shape modality distribution more than the opinions and attitudes of physicians. These factors may operate at the level of the facility or health care system.

So what are the implications of our study? First, we suggest that nephrologists attitudes towards modality selection are actually similar in different parts of the world, and that differences in utilization, for example between the US and the British Isles, reflect other factors. Secondly, if we accept the opinions of the nephrologists surveyed, the UK should look to increase the number of satellite and home HD facilities, as well as the number of automated PD systems available. However, doing so will move the thrust of dialysis care out to the community, and pre-emptive planning for increased community support services, in the form of community nephrologists, increased GP training programmes or the introduction of dialysis nurse practitioners, needs to be an integral part of the planning.

Finally, because modality mix is an important determinant of costs and may impact on patient outcomes and quality of life, there is an urgent need to better define the optimum modality distribution. It is possible that this will vary between and even within countries, depending upon population density, demographics, and other factors. Indeed, after an era during which PD in the UK may have been over-utilized, the recent drift towards 40% of prevalent dialysis patients may represent an appropriate adjustment. The renal community should be encouraged to explore these issues of modality selection and distribution further.



   Notes
 
Correspondence and offprint requests: Dr S. V. Jassal, University Health Network, 225-11EN, 200 Elizabeth St, Toronto, M5G 2C4, Ontario, Canada. Email: vanita.jassal{at}uhn.on.ca Back



   References
 Top
 Abstract
 Introduction
 Subjects and methods
 Results
 Discussion
 References
 

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Received for publication: 26. 6.01
Accepted in revised form: 6.11.01