The effect of sex inequality on solid organ transplantation: A systematic review and meta-analysis

  • Author Footnotes
    1 ST and RMR contributed equally as first author.
    Sofia Tejada
    1 ST and RMR contributed equally as first author.
    Centro de Investigación Biomédica En Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain

    Clinical Research/Epidemiology in Pneumonia & Sepsis (CRIPS), Vall d'Hebron Institut of Research (VHIR), Barcelona, Spain
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  • Author Footnotes
    1 ST and RMR contributed equally as first author.
    Raquel Martinez-Reviejo
    1 ST and RMR contributed equally as first author.
    Centro de Investigación Biomédica En Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, Madrid, Spain

    Clinical Research/Epidemiology in Pneumonia & Sepsis (CRIPS), Vall d'Hebron Institut of Research (VHIR), Barcelona, Spain
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  • Taísa A. Nogueira
    Universidade Federal de Campina Grande, Campina Grande, Brazil
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  • Aroa Gómez
    Department of Donor & Transplant Coordination, Vall d'Hebron University Hospital, Barcelona, Spain
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  • Teresa Pont
    Department of Donor & Transplant Coordination, Vall d'Hebron University Hospital, Barcelona, Spain
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  • Xuelian Liao
    Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China

    West China Tianfu Hospital, Sichuan University, Chengdu, China
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  • Zheng Zhang
    Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu, China
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  • Oriol Manuel
    Service of Infectious Diseases, Lausanne University Hospital, Lausanne, Switzerland

    Transplantation Center, Lausanne University Hospital, Lausanne, Switzerland
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  • Jordi Rello
    Corresponding author.
    Clinical Research/Epidemiology in Pneumonia & Sepsis (CRIPS), Vall d'Hebron Institut of Research (VHIR), Barcelona, Spain

    Clinical Research CHU Nîmes, Université de Nîmes-Montpellier, France

    Medicine Department, Universitat Internacional de Catalunya (UIC), Sant Cugat, Spain
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  • Author Footnotes
    1 ST and RMR contributed equally as first author.
Published:December 28, 2022DOI:


      • Why carry out this study?
      • Does sex matter? The importance of sex inequalities in solid organ transplantation.
      • There is limited evidence assessing the impact of sex on transplant recipient outcomes.
      • What was learned from the study?
      • Females account for 1/3 of the solid organ transplant recipient's cohort and have higher survival than males after liver and kidney transplant.
      • Allograft dysfunction was influenced by combination of donor-recipient sex and age.
      • Consider sex as a factor to optimize the management of transplant patients.



      Sex disparities are related to biological differences, which may have significant impact on patient and allograft outcomes. The aim was to investigate the impact of sex on clinical and safety outcomes after solid organ transplantation (SOT).


      A systematic review and meta-analysis was performed. Observational studies comparing females vs. males after SOT were considered for inclusion after a systematic search of the Pubmed, Cochrane Library, and Web of Science databases conducted from 2016 to 2021. Primary outcome was mortality. PROSPERO register number: CRD42021282615.


      After retrieving 1103 studies, 22 observational studies (1,045,380 subjects) were finally deemed eligible for inclusion. Females accounted 36.3% of SOT recipients, but presented significantly lower mortality (odds ratio (OR): 0.87, 95% confidence interval (CI): 0.83–0.92, I2=78%). In subgroup analyses, mortality was significantly lower in females undergoing liver (OR: 0.89 95%CI: 0.86–0.92, I2=0%) or kidney transplantation (OR: 0.82 95%CI: 0.76–0.89, I2=72%). Male sex was consistently reported as a protective factor against hospital readmission. Among the outcomes, allograft dysfunction was influenced by a combination of donor-recipient sex and age. Data on overall infections were inconclusive. Several reports suggest a higher risk of malignancy among males.


      Females represent one-third of SOT recipients but have higher survival rates than males after liver and kidney transplantation. The impact on graft dysfunction was heterogeneous. While further research is warranted, our findings should encourage clinicians and researchers to consider sex as a factor when taking decisions regarding SOT management.



      SOT (Solid Organ Transplantation), RMLH (restricted maximum likelihood), CI (Confidence Interval), OR (Odds Ratio), HR (Hazard ratio), MELD-Na (Model for End-Stage Liver Disease incorporating sodium levels), PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis)
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