What is already known about this topic and why is it important?

Population-based studies indicate that the proportion of women with predialysis chronic kidney disease (CKD) is higher than that of men. However, the opposite is the case for patients initiating kidney replacement therapy (KRT) for end-stage kidney disease (ESKD): across all European countries as well as in the US there is a higher proportion of men on KRT. This paradox is likely due to a faster declining kidney function in men than in women, and because elderly men are less likely to choose conservative care than elderly women. A review of the sex distribution in relation to the different primary renal diseases that result in ESKD requiring KRT may contribute to the discussion on this gender-paradox. However, to the best of our knowledge, no in-depth analyses of original primary renal disease distribution among men and women on KRT have been performed so far.

In addition, in patients with predialysis CKD, mortality is higher in men than in women. On the other hand mortality among patients on KRT is similar in men and women. Therefore also a comparison of survival among men and women for the different primary renal diseases could provide insight into the disparities between men and women.

How will you carry out your study?

We will analyse the distribution of primary renal diseases among men and women starting KRT for ESKD. In addition, we will study the mortality of men and women for the different primary renal diseases by including individual patient data from renal registries that are submitting data to the ERA-EDTA Registry.

How will you decide which patients are included in your study?

We will include data from all patients who started KRT between 1/1/2008 and 31/12/2017 from renal registries within Europe providing individual patient data to the ERA-EDTA Registry. Patients who indicated that their data shouldn’t be used for research will not be included.

How many patients do you anticipate including?

We expect to include data from 360.000 patients of which 65,000 patients are from the UK (England, Wales and Northern Ireland).

For how long will you follow up these patients?

For the analysis of primary renal disease distribution by sex the patients need not be followed over time; for the survival analyses patients will be followed for a maximum of five years.

What new information will your study generate and how will this benefit patients?

Knowledge on sex specific primary renal disease distribution among patients on KRT might contribute to a better understanding of higher KRT incidence in men and have potential clinical implications.