Regional variability in the incidence of end-stage renal disease: an epidemiological approach

Background. Regional variability in the incidence of end-stage renal disease (ESRD) in Austria is reported. Our aim was to investigate the reason for low rates in the state of Tyrol. Methods. ESRD incidence data were obtained from the Austrian Dialysis and Transplantation Registry. Additional sources were two health interview surveys, the Hospital Discharge Registry, the Mortality Registry and the Drug Wholesale Registry. Results. Between 1995 and 1999, 4811 new cases of ESRD were recorded; the state of Tyrol (T) had a mean annual, age-adjusted incidence of 97.9/1000 000 population [95% confidence interval (CI) 86.9-109.1], a number significantly lower than that for the rest of Austria [(RA), 120.9 (95% CI 116.9-124.5); P < 0.001]. This was due mainly to a difference in the incidence of ESRD patients with type 2 diabetes mellitus [(DM-2) T = 12.2 (95% CI 8.2-16.2) vs RA = 28.9 (95% CI 27.2-30.6); P < 0.001]. When these patients were excluded, the difference in the overall ESRD incidence disappeared. When data from various registries were analysed for the prevalence of DM, a highly significant correlation was found between ESRD incidence and DM. Conclusion. We conclude that the variability in the ESRD incidence in Austria is explained mainly by regional differences in DM-2. Data from similar studies might be useful for predictions concerning resource allocation for ESRD programmes in the future.