Kidney Week

Abstract: FR-PO0422

Sex Differences in Outcomes and Care Processes After Outpatient AKI

Session Information

• AKI: Biomarkers, Diagnostics, and Risk Prediction
  October 23, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 102 AKI: Clinical, Outcomes, and Trials

Authors

• Birkelo, Bethany, University of Minnesota Medical School, Minneapolis, Minnesota, United States

Bethany Birkelo, DO, MSc

• Velusamy, Kailash Rohit, University of Minnesota Medical School, Minneapolis, Minnesota, United States

Kailash Rohit Velusamy, MS

• Greevy, Robert, Vanderbilt University Medical Center, Nashville, Tennessee, United States

Robert Greevy, PhD

• Murphy, Daniel P., University of Minnesota Medical School, Minneapolis, Minnesota, United States

Daniel P. Murphy, MD, MS

• Siew, Edward D., Vanderbilt University Medical Center, Nashville, Tennessee, United States

Edward D. Siew, MD, MS, MSc

• Drawz, Paul E., University of Minnesota Medical School, Minneapolis, Minnesota, United States

Paul E. Drawz, MD, MS

Background

Biological sex modulates risk of acute kidney injury (AKI). However, the impact of sex on outcomes after AKI is poorly understood. It is also unknown if there are sex disparities in kidney-focused care after AKI. Sex differences in outcomes and care received by patients with outpatient AKI (OP-AKI) have not been previously examined.

Methods

We conducted a retrospective cohort study to examine sex differences in outcomes and care processes after OP-AKI among adults in the M Health Fairview health system. OP-AKI was defined by a 50% or greater increase in creatinine identified on an outpatient lab measurement compared to a moving baseline (defined as the average of up to 3 of the last outpatient creatinine values from 30–365 days prior). We used inverse probability of treatment weights to balance distributions of 16 covariates between males and females (demographics, baseline conditions and lab values, vital signs, number of hospitalizations during the baseline period, AKI severity, and AKI recovery status at time zero). We used Cox proportional hazards models to analyze the effect of female sex on the outcomes. Time zero was 14 days after the qualifying creatinine value. Clinical outcomes included mortality, eGFR <30 ml/min/1.73m² (with at least 50% drop in eGFR compared to baseline), and recovery to within 10% of baseline creatinine. Care process outcomes included creatinine and proteinuria measurement at one year after OP-AKI.

Results

Among 6,264 patients (60% female), female sex was associated with a lower risk of death (HR 0.86, 95% CI 0.76–0.97), and a lower likelihood of kidney recovery to within 10% of baseline creatinine (HR 0.93, 95% CI 0.87–1.00) but no difference in risk of eGFR <30 ml/mi/1.73m² (HR 1.00, 95% CI 0.89–1.11). Female sex was associated with a lower likelihood of creatinine reassessment (HR 0.89, 95% CI 0.82–0.98) and a lower likelihood of proteinuria assessment which was not statitstically significant (HR 0.92, 95% CI 0.80–1.06).

Conclusion

Female sex was associated with a lower likelihood of recovering kidney function after OP-AKI but there was not a statistically significant association between sex and advanced CKD (eGFR <30 ml/min/1.73m²). We found sex disparities in care processes after OP-AKI, with females being less likely to have creatinine reassessed at one year after OP-AKI.