Are there gender disparities in vascular access at dialysis initiation in France. A mediation analysis using the data of the REIN registry

Introduction Vascular access is reported to differ among gender groups. Female gender is associated with catheter use in many countries. The objective of this study was to assess the association between gender and vascular access at dialysis initiation and to explore the potential mediators of the pathway. Description Using the REIN registry, patients who started dialysis between the 1st January 2017 and the 30th June 2018 were included. Methods Logistic regression was used to study factors associated with the use of a catheter. A mediation analysis with a counterfactual approach was carried out to evaluate if hemoglobin and albumin levels, glomerular filtration rate (GFR) at dialysis initiation and social deprivation were mediators of the relation. Results Among the 16,032 patients included, 5627 were female; 50.9% started dialysis with a catheter. Catheter use was associated with age   80, cardiovascular disease, chronic heart failure, active cancer, chronic respiratory and liver disease. Obesity and polycystic disease were associated with arteriovenous fistula. Female gender was associated with a higher use of catheter (OR: 1.32 [95% CI: 1.23–1.42]) in the multivariate analysis. The association was mediated by albuminemia (OR: 1.07 [95% CI: 1.05–1.09]), hemoglobin level (OR: 1.03 [95% CI: 1.02–1.04]), GFR at dialysis initiation (OR: 1.04 [95% CI: 1.03–1.05]) and social deprivation (OR: 1.00 [95% CI: 1.00–1.01]). Conclusion Female gender is associated with a higher use of catheter at dialysis initiation in France. The effect was partially mediated by hemoglobin and albuminemia, a proxy of predialysis care, GFR at dialysis initiation and social deprivation. However, a direct effect of gender on catheter use persisted. Further studies would be interesting to identify other mediators.