[Results of the cooperative study of Spanish peritoneal dialysis registries: analysis of 12 years of follow-up].

INTRODUCTION AND OBJECTIVES: There is currently no registry that gives a complete and overall view of the peritoneal dialysis (PD) situation in Spain. However, a report on PD in Spain was developed for various conferences and meetings over several years from data provided by each registry in the autonomous communities and regions. The main objective of this study is to analyse this data in aggregate and comparatively to obtain a representative sample of the Spanish population on PD in recent years, in order that analysis and results in terms of demographic data, penetration of the technique, geographical differences, incidence and prevalence, technical aspects, intermediate indicators, comorbidity, and outcomes such as patient and technique survival may be extrapolated to the whole country. DESIGN, MATERIAL AND METHOD: Observational cohort study of autonomous PD registries, covering the largest possible percentage of the adult Spanish population (over 14 years of age) on PD, at least in the last decade (1999-2010), and in the largest possible geographical area in which we were able to recruit. A precise data collection strategy was followed for each regional registry. Once the information was received and clarified, they were added as aggregate data for statistical study.

RESULTS: The regional registries that participated represent a total geographical area that encompasses 32,853,251 inhabitants over 14 years of age, 84% of the total Spanish population older than that age. The mean annual rate of incidents per million inhabitants (ppm) was variable (between 17.81 ppm in Andalusia and 29.90 ppm in the Basque Country), with a discrete and permanent increase in the overall PD incidence in Spain being observed in recent years. The mean annual prevalence per million population (ppm) was very heterogeneous (from 42 to 99 ppm). A mean progressive increase in the use of automated peritoneal dialysis (APD) was observed. The peritonitis rate was approximately one episode every 25-30 months/patient, with a slight decrease being observed in recent years. The causes of discontinuing PD were distributed fairly evenly between communities; almost a third was due to patient death (mean 28%), a third was due to renal transplantation (mean 39%) and a third was due to transfer to haemodialysis (technique failure: mean 32%). The main comorbidities were cardiovascular disease (30.2%) and diabetes mellitus (24.2%). The overall accumulated mean survival was 92.2%, 82.8%, 74.2%, 64.8% and 57% after one, two, three, four and five years respectively. There was significantly and independently worse survival for older patients and those with cardiovascular disease, patients with diabetes mellitus, those on continuous ambulatory peritoneal dialysis (vs. APD), those who started PD before 2004 (analysed in Andalusia and Catalonia), and patients with lower residual renal function at the start of PD (analysed in the Levante registry). Similarly, the technique survival has improved, showing a mean figure above 50% after 5 years.

CONCLUSIONS: The incidence and prevalence of PD in Spain are growing moderately and in a generalised manner and continue to maintain an irregular distribution by autonomous community. Both patient and technique survival were greater than 50% after 5 years, with an improvement being observed in recent years, and are comparable to countries with better results in this treatment.