To the editor:

In response to the letter of Dr. del Pozo et al. the Group on Quality Management of the SEN wants to thank this kind of initiatives, since one of the fundamental characteristics of all quality systems, and in particular of defined indicators and standards, is to be open to continuous reviews and changes. For this reason a multicentric study is being currently carried out to validate the proposed quality indicators, with the aim to analyze their feasibility and to know the actual standards in our setting.

The study is ongoing, but the participation is still open for all interested centers. In fact, one of the middleterm objectives is to have a registry available, representative of current quality standards in Spain. At this moment we possess modules of indicators measurement, developed by the main computer programs employed in hemodialysis like Nefrosoft® (Visuallimes) and Renalsoft® (Baxter), and others that are being developed like Nefrolink®. With them it is easy to share the results.

We agree with all the suggestions made by the group of Alcoy. Our intention is to progressively change both the indicators and the standards, as well as the monitoring periods, in such a way that at the end they fit to our every-day practice. Some defined standards are probably too ambitious but we hope that the multicentric study will helps to adjust them to the daily routine. For example, in the multicentric study the mean of the percentage of patients with Hb values > 11 g/dL was 81.24 ± 9.97 (similar to what Dr. del Pozo et al. propose) and the mean of the superior quartile was 93.2%. The mean percentage of patients with Hb > 13 g/dL was 20% of the total sample (3142 patients) with a big inter-center variability. The aim is to maximize the percentage of patients with Hb values in a range between 11 and 12 g/dL. Considering the last recommendations we agree that it is necessary to include among the indicators the percentage of patients with Hb values > 13 g/dL

We also agree that phosphorus levels should be frequently measured, and it seems logical that this measurement should be as frequent as, or even more frequent than, PTH determination. In fact, in the indicators module and in our study the periodicity for phosphorus determination was established on monthly base. The preliminary data from the multicentric study for these indicators were: 1) compliance with PTH standard (between 150 y 300 pg/mL) 32% ± 10.9 %, with some centers reaching 46%; 2) compliance with phosphorus standard (< 5.5 mg/dL) 70.8%, with a maximum of 84.4%.

With respect to the last issue about the inclusion of the blood pressure measurement as a priority indicator, we would like to explain, that it was not initially included because the standard of this indicator is not yet enough clear. In a recent study1 the achievement of the blood pressure objective (BP < 140/90) in patients in hemodialysis was associated with a higher mortality risk, while achievement of other indicators yielded favorable results. We conclude that the objective for the BP is extrapolated from those in the general population, and that randomized controlled studies are needed to identify the optimal blood pressure value in patients on hemodialysis.

In summary, this matter is open to discussion, and in permanent change. Every proposed indicator can only be used as an orientation. With the results of the multicentric study and also with the different inputs, the quality indicators monitoring system will be progressively defined.