Sex differences in deceased donor organ transplantation rates in the United States

BACKGROUND.: Greater numbers of organs transplanted from deceased male donors have been attributed to sex differences in the causes of death. Understanding sex differences in transplantation will help to design interventions to mitigate disparities in transplantation. METHODS.: Using 62,643 deceased donors from the United Network for Organ Sharing data from 1994 through 2005, we estimated sex-specific prevalence of donors, age- and sex-specific transplantation rate, and transplantation by organ type, accounting for donor demographic, clinical, and processes of care variables. RESULTS.: There was greater male donor prevalence (58.8%). Age-specific transplantation rates from men were greater for those younger than 35 years (men vs. women, 3.89 vs. 3.56 organs transplanted per donor; P<0.001) but lower for older men (2.27 vs. 2.44 organs per donor; P<0.001), whereas age-standardized rate of transplantation was lower from men (2.78 vs. 2.85 organs per donor; P<0.001). This sex disparity persisted when adjusted for differences in demographics, comorbidity, mechanism of death, and processes of care such that a 3% lower rate of organs were transplanted from men (adjusted rate ratio, 0.97; 95% confidence interval: 0.96-0.98). Of individual organs, there was a lower rate of lung (20%), liver (1%), and kidney (1%) transplantation from men, whereas there was a lower rate of heart (16%) and pancreas (7%) transplantation from women. CONCLUSIONS.: Overall, lower transplantation rate from men may be due to unmeasured factors or it could be secondary to biologic differences in organ function. Further research is required to understand sex differences in organ transplantation rates.