Trends in Sex Disparities in Access to Kidney Transplantation: A Nationwide US Cohort Study

Abstract

Rationale & Objective

Women with kidney failure have reduced access to kidney transplantation compared with men. We examined trends in sex inequities in access to transplantation over time.

Study Design

Retrospective cohort study.

Setting & Participants

2.3 million adults identified within the US Renal Data System, aged 18-79 years, who initiated kidney replacement therapy (KRT) between 1997 and 2020.

Exposure

Era of KRT (1997-2000, 2001-2004, 2005-2008, 2009-2012, 2013-2016, or 2017-2020), sex (male or female).

Outcome

Placement onto the kidney transplant waitlist, or living-donor kidney transplant (LDKT) among all individuals initiating KRT, and deceased donor kidney transplantation (DDKT) among patients on the waitlist.

Analytical Approach

Multivariable cause-specific hazard models to analyze the association between sex and placement onto the waitlist, LDKT, and DDKT, by era, overall, and by categories of age, race, and cause of kidney failure.

Results

Sex inequities in waitlisting became less pronounced over time. During 1997-2000 the adjusted HR comparing men with women was 0.81 (95% CI, 0.79-0.83); by 2017-2020, it had narrowed to 0.86 (95% CI, 0.85-0.87). For the outcome of LDKT, during 1997-2000, the adjusted HR comparing men with women was 0.89 (95% CI, 0.85-0.93) and by 2017-2020 had widened to 0.79 (95% CI, 0.76-0.82). For the outcome of DDKT, during 1997-2000, the adjusted HR comparing men with women was 0.92 (95% CI, 0.89-0.95) and by 2017-2020 had widened to 1.16 (95% CI, 1.14-1.19). Sex inequities in waitlisting and LDKT were greatest in women (vs men) with diabetes (27% and 37%, respectively, in 2017-2020) and older adults 60-79 years (24% and 34%, respectively, in 2017-2020), but were broadly similar across race groups.

Limitations

Residual confounding; unknown true medical eligibility for transplant.

Conclusions

Since 1997, sex inequities in waitlisting have improved but remain significant, especially for women who are older and who have diabetes-attributed kidney failure. Worsening sex inequities in LDKT among women and DDKT among waitlisted men warrant further study.

Plain-Language Summary

Women with kidney failure have historically had poorer access to kidney transplantation than men. The goal of the current study was to see whether access to transplantation, defined as placement onto the transplant waitlist or living (LDKT) or deceased donor kidney transplantation (DDKT), has changed over time using national registry data from >2.3 million adults initiating kidney replacement therapy in the United States. Overall, this study showed that since 1997 sex inequities in placement on the transplant waitlist have improved but remain significant, especially for women who are older or have diabetes. Unfortunately, sex inequities in LDKT favoring men have worsened over time while declines in DDKT appear to have impacted men more than women. These findings have implications for the design of policies and interventions to improve transplant equity.