Opinions regarding outcome differences in European and US haemodialysis patients

Claudio Ronco1 and Daniele Marcelli2

1 Department of Nephrology, St Bortolo Hospital, Vicenza, and 2 Lombardy Dialysis and Transplant Registry, Milan, Italy

Correspondence and offprint requests to: Dr Claudio Ronco, Department of Nephrology, St Bortolo Hospital, Viale Rodolfi, 36100 Vicenza, Italy.

Abstract

Study goal and design. The aim of this evaluation was to understand why outcomes seem to be different in different parts of the world. In an attempt to look at this question from a point of view other than that necessarily adopted by epidemiological studies, we decided to explore the personal opinion of a selected group of American (US) and European (EU) experts by means of a simple questionnaire. A 13-item questionnaire was sent to 14 internationally recognized opinion leaders in the field of haemodialysis: all seven Europeans and five of the seven Americans responded. The answers to each question were stratified in order to highlight the key differences between the experts in the different continents.

Results. Ten of the 12 respondents (six EU and four US) said that dialysis outcomes are better in Europe; nine (six EU and three US) confirmed their opinion after taking patient characteristics into account. When asked to suggest reasons for this difference, the highest score was given to the quality of procedures and medical training with no differences between EU and US physicians. This was followed by three other factors that received the same overall score (financial issues, doctor bedside time and quality of pre-dialysis care), but it is interesting to note that the Europeans attributed considerably greater importance to bedside time than their US counterparts.

Conclusion. It seems that the reported difference in dialysis outcomes between Europe and the US is a widely accepted fact. Although directed towards few respondents, our questionnaire does suggest some differences in the approach towards dialysis and end-stage renal disease patients.

Introduction

A large number of end-stage renal disease (ESRD) patients throughout the world are treated with renal replacement therapy (RRT) [1], but they are considerably different in terms of age, ethnological characteristics, underlying renal diseases and co-morbidities [25].

Since `The Morbidity, Mortality and Prescription of Dialysis Symposium' held in Dallas in 1989, it has become increasingly clear that the US mortality rate among dialysis patients (over 20 per 100 patient-years) is relatively high [25]. Despite various strategies for influencing outcomes suggested by the United States Renal Data System (USRDS), this mortality rate has decreased only slightly [3].

In contrast, the reported mortality rates in other Western countries are lower–even as low as 10 per 100 patient-years [4]. This striking difference is explained partly on the basis of patient characteristics (age, diabetes, gender, ethnological characteristics, etc.), but may also be due to differences in treatment and/or the level of reliability of the various dialysis registries [6].

However, as Dr Philip Held has recently pointed out (`Strategies for influencing outcomes in pre-ESRD and ESRD patients' meeting, Washington DC, 1998), we should avoid excessive chauvinism when interpreting these figures; it is more important simply to understand why outcomes seem to be different in different parts of the world [7].

In an attempt to look at this question from a point of view other than that necessarily adopted by epidemiological studies, we decided to explore the personal opinion of a selected group of American (US) and European (EU) experts by means of a simple questionnaire.

Methods

The 13-item questionnaire was sent to 14 internationally recognized opinion leaders in the field of haemodialysis: seven Europeans (UK, Germany, France, Belgium, Italy, Sweden and Spain) and seven Americans. The questionnaire (see Appendix) included both open and closed questions, but the former were designed in such a way as to allow the answers to be grouped in a few simple categories and, when possible, attributed a score (3=most important, 1=least important).

The answers to each question were stratified in order to highlight the key differences between the experts of the different continents.

Results

Of the 14 experts, 12 replied to the questionnaire (seven Europeans and five Americans). The answers are summarized below.

Ten respondents (six EU and four US) said that dialysis outcomes (Appendix, question 1) are better in Europe; two disagreed. After taking into account patient characteristics, nine (six EU and three US) confirmed their opinion (Figure 1Go). When asked to suggest reasons for this difference, the highest score was given to the quality of procedures and medical training, with no differences between EU and US physicians (Figure 1Go). This was followed by three other factors that received the same overall score (financial issues, doctor bedside time and quality of pre-dialysis care), but it is interesting to note that the European physicians attributed considerably greater importance to bedside time. The other factors mentioned were social issues (patient education, compliance and psychology, the structure of society, public services) and the adequacy of data collection, which was considered more important by the Americans than by the Europeans. These results were confirmed by the answers to a second similar group of questions (Appendix, question 2) about ESRD care in general.



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Fig. 1. (Left) The answers to the first questions and (right) the scores of the suggested factors explaining the difference in outcome.

 
In relation to which factors could improve outcomes in the US (Appendix, question 3), the greatest importance was given to the quality of procedures (Figure 2Go). This was followed by healthcare and financial issues, and doctor bedside time (which again revealed a marked difference between the American and European physicians). The other two factors mentioned were pre-dialysis care and medical training (Figure 2Go).



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Fig. 2. The scores given to possible ways of improving outcomes in the US.

 
In order to try to give some weight to these answers, the respondents were asked a series of questions about the normal clinical practice in their own centres (Appendix, question 4). All of the Europeans (and none of the Americans) stated that a physician attended every dialysis session. Dialysers are reused in four of the five American centres and in none of the European centres. There was no difference between the European and American centres in terms of the routine use of biocompatible membranes. Five of the European and none of the American centres used convective haemodialysis techniques (i.e. haemodiafiltration or haemofiltration). All of the respondents declared that treatment adequacy was monitored by means of urea kinetics, but the Europeans gave priority to clinical parameters (Figure 3Go). The DOQI monitoring and prescription guidelines were considered useful but not mandatory by the majority of the respondents, only two of whom (one EU and one US) considered them targets that could be definitely reached in all patients.



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Fig. 3. Answers to the questions concerning dialysis treatment.

 
Discussion

The results of this survey show that the majority of the selected opinion leaders recognize that dialysis outcomes are better in Europe, although there were some differences as to why this is so.

It would seem that the few who disagreed had doubts about the adequacy of the data collection in the different national registries, and it is true that these are not strictly comparable. The USRDS appears to be the most complete and reliable source of data because of the mandatory nature of the response and data submission, and its more complete ascertainment of approximately 10% of deaths not reported by ESRD facilities [3]. However, it should be noted that a number of databases using volunteered information are well organized and relatively complete [8,9]. One answer to the problem of making comparisons could be to restrict them to registries of this kind rather than to insist on making national comparisons. In this respect it is worth pointing out that the EDTA database, for example, has an overall response rate of 66%, with five countries reporting almost 100% responses [10].

Setting aside this statistical question, the majority of respondents attributed the difference in outcome to differences in the quality of treatment procedures and medical training. A major difference in treatment procedures is the fact that dialysers are still widely reused in the US, whereas this practice has been largely abandoned (or is forbidden) in European countries. A second difference is that the use of highly permeable membranes and convective techniques is much more widespread in Europe, and it has been shown that this leads to a lower incidence of long-term dialysis-related amyloidosis [1113] and a lower level of circulating macromolecules, such as B2-microglobulin [14]. Despite the fact that sophisticated technologies such as urea and blood volume sensors have been proposed and used [15], European nephrologists place more emphasis on clinical parameters, including blood-pressure control [16], increased treatment tolerance, control of phosphataemia [17] and parathyroid hormone, acid–base correction and a positive or neutral nitrogen balance [18].

This difference in treatment approach is at least partially due to differences in personnel qualifications and training. Given that research and training in the basic sciences is privileged in the US, and great emphasis is placed on physiology and experimental nephrology in academic training programmes, a number of US experts consider the average training of the American physician in haemodialysis probably insufficient or inadequate [19].

One of the interesting findings of our survey (and possibly a consequence of what has been said above) is the remarkable difference between the European and American respondents in terms of the importance placed on the time physicians spend with their patients. This comes second overall as a reason for the difference in outcomes between the two continents (together with financial issues and pre-dialysis care), but is considered to be the most important reason by the Europeans. Furthermore, a recent study by a group in Atlanta [20] found that `the frequency of physician visits with patients during dialysis was associated with facility mortality rate'.

When considering possible ways of improving ESRD care in the US, it is not surprising that the greatest importance was given to the same issues. However, it is particularly interesting to note the greater weight given by the Americans to pre-dialysis care. It is well known that the emphasis placed by European healthcare systems on the early referral of chronic renal failure patients to specialized centres has had a positive impact on patient outcome not only in the pre-dialysis phase [21,22], but also during dialytic treatment [23]. One important factor to bear in mind when considering the advantages of such early referral is the fact that it allows sufficient time to create an internal arterio-venous fistula in order to ensure an appropriate vascular access before the initiation of haemodialysis. This also partially avoids the need to use the polytetrafluorsethilen or bovine grafts that have been associated with a poorer outcome [24]. Furthermore, the fact that patients with early-stage kidney failure have a longer period of pre-dialysis contact with a nephrologist means that they can be suitably prepared for ESRD treatment, and that the treatment modality itself can be selected in the most appropriate manner. This early contact has the additional advantage that the patient can be given detailed advice concerning all of the factors affecting the course of the disease and the result of dialysis (blood pressure control, diet, adequate caloric intake, etc.), and this clearly leads to greater patient confidence and treatment compliance.

The other two factors suggested by the opinion leaders as affecting outcome were financial and social issues. It is very difficult to make any precise evaluation of the effect of finance because of the fundamental differences between the healthcare systems in the US and the various European countries. As far as social questions are concerned, it has been suggested that family support plays a considerable role in ensuring better compliance to treatment and fewer cases of withdrawal from therapy [20]. It may well be that differences in family and local community life between Europe and the US contribute to the difference in dialysis outcome.

It should be pointed out that the answers to the questions concerning actual clinical practice in the centres directed by the respondents to the questionnaire cannot be directly extrapolated as a reflection of national practices.

In conclusion, despite the still inevitable differences in the databases of different countries, it seems that the reported difference in dialysis outcome between Europe and the US is accepted by the majority of opinion leaders. Although directed towards only a few respondents, our questionnaire does indicate some clear differences in the approach towards dialysis and ESRD patients. What is now necessary is that nephrologists on both sides of the Atlantic (and in the rest of the world) come together in order to try to create a common approach in the best interests of all ESRD patients.

Appendix

Questionnaire

  1. Are dialysis outcomes better in Europe?
    Is this true even when the data are adjusted for case mix?
    If so, identify and score three factors involved in this difference between Europe and the US.
  2. Is ESRD care better in Europe?
    If yes, identify and score three factors involved in this difference.
  3. In your opinion, what could be done to improve outcomes in the US?
  4. Do you visit your patients every dialysis?
    Do you reuse dialysers?
    Do you use biocompatible membranes?
    Do you use techniques other than HD (HF, HDF)?
    Do you monitor adequacy by means of urea kinetics?
    Do you give priority to clinical parameters over Kt/V?
    What do you think of DOQI guidelines?

Acknowledgments

We would like to thank the following experts for answering our questionnaire: Karel Leunissen (The Netherlands), Bernard Canaud (France), Francesco Locatelli (Italy), Fernando Valderrabano (Spain), Norbert Lameire (Belgium), Nicholas Hoenich (UK), Conrad Baldamus (Germany), and Juan Bosch, Thomas Golper, Friedrich Port, Raymond Hakim, Nathan Levin, Michael Lazarus and William Owen (USA).

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