Environmental factors influencing the survival of chronic dialysis patients.

Background: There have been few investigations into the effects of environmental factors on the outcome of end-stage renal disease.
Methods: We investigated factors influencing the survival of dialysis patients in each prefecture of Japan by analyzing data from the Japan Statistics Bureau and Japanese Society for Dialysis Therapy using univariate and multivariate regression analysis.
Results: Univariate analysis showed that the number of dialysis specialists (p = 0.028, r = 0.319), the density of dialysis centers (the number in relation to the area of each prefecture, p = 0.018, r = 0.344), the average annual temperature (p < 0.0001, r = 0.686), and the mortality rate of the general population with cerebrovascular disease (p = 0.014, r = -0.355) were correlated with the 1-year survival of new dialysis patients from 2005 to 2007. Multivariate regression analysis showed that the average annual temperatures were extracted as determinants of the 1-year survival rate of new dialysis patients (p < 0.0001, F = 40.11, R(2) = 0.471, R(2)' = 0.460).
Conclusion: The average annual temperatures could have an influence on the survival of dialysis patients. Survival of new dialysis patients by prefecture in Japan may be influenced by environmental factors that cannot be controlled medically after the initiation of dialysis.