Incidence, prevalence and crude survival of patients starting dialysis in Portugal (2010-16): analysis of the National Health System individual registry

Abstract

Background: The Portuguese Society of Nephrology (PSN) reported that Portugal has one of the highest incidences of dialysis in Europe. However, this claim was based on aggregated data supplied by dialysis providers, hampering comparisons between countries. In 2009, an individual registry of patients starting dialysis was set up by the Portuguese Ministry of Health. We analysed individual data of patients starting dialysis from January 2010 until December 2016.

Methods: Demography, starting treatment day, modality, regional distribution and outcomes, such as death, recovery of renal function, transfer to renal transplantation, peritoneal dialysis or conservative management, were extracted. Incidence, prevalence and survival analysis were calculated and compared with the PSN registry.

Results: Out of 19 190 registrations, 16 775 were incident patients (61.8% men). Yearly incidence of renal replacement therapy was 250, 248, 229, 239, 230, 231 and 244 per million population (p.m.p.) for 2010 to 2016, compared with 235, 224, 218, 230, 234, 225 and 239 p.m.p. reported by the PSN registry. On the other hand, prevalence increased from 998 p.m.p. in 2010 to 1286 p.m.p. in 2016, compared with 1010 p.m.p. in 2010 increasing to 1203 p.m.p. in 2016 from the PSN registry. The regions of Alentejo (122.9 p.m.p.) and the the Centre (160.8 p.m.p.) had the lowest regional incidence, while Lisbon had the highest (386 p.m.p. in 2016). Unadjusted survival analysis revealed that 93.5% of the patients were alive on the 91st day, whereas 85.2 and 78.3% were alive at 1 and 2 years, respectively. Crude survival at 7 years was 40%.

Conclusions: For the first time, an individual registry of patients starting dialysis in Portugal was subject to analysis and added new information about long-term survival and regional differences in the incidence and prevalence of renal replacement therapy. We were able to confirm that Portugal has one of the world's highest incidences and prevalences of dialysis. We also demonstrate, for the first time, a striking regional difference in the incidence of dialysis and an excellent early and long-term survival of patients on dialysis. These results compare well with other European countries in terms of the dialysis efficiency.

Keywords: ESRD; Portugal; incidence; prevalence; survival.

FIGURE 1

Unadjusted survival analysis of patients starting RRT in the period of analysis (2010–16). Data from whole country. Source: Online registry of the National Health Service, Portugal.

FIGURE 2

Survival as a function of the age at RRT initiation (numbers next to the age group categories represent number at risk at the beginning of follow-up). Data from whole country. Source: Online registry of the National Health Service, Portugal.