Recovery of kidney function after acute kidney disease-a multi-cohort analysis

Area of Science:

• Nephrology
• Epidemiology
• Public Health

Background:

• Lack of standardized definitions for kidney function recovery after AKI and AKD hinders research and clinical practice.
• Variability in recovery rates across different populations and clinical subsets remains poorly understood.

Purpose of the Study:

• To establish consensus definitions for evaluating kidney function recovery after AKI and AKD.
• To analyze how recovery varies across diverse populations and clinical subsets using a federated analysis of multiple cohorts.

Main Methods:

• Federated analysis of four population-based cohorts from Canada, Denmark, and Scotland (2011-2018).
• Incident AKD identified by serum creatinine changes within 48 hours, 7 days, 90 days, and 365 days, based on KDIGO criteria.
• Kidney recovery defined by AKD resolution and creatinine below 1.2x baseline; evaluated transitions between non-recovery, recovery, and death up to 1 year.

Main Results:

• Pooled 1-year mortality rates varied by AKD definition timeframe: 40% (48h), 40% (7d), 37% (90d), and 22% (365d).
• Pooled 1-year non-recovery rates were 19% (48h), 30% (7d), 25% (90d), and 37% (365d).
• Recovery by 14 and 90 days was often not sustained at 1 year; outcomes varied significantly by age, sex, and comorbidities.

Conclusions:

• KDIGO AKD (up to 90 days) is prognostically similar to KDIGO AKI (7 days) and includes more individuals.
• Kidney function outcomes post-AKI/AKD are influenced by patient demographics and comorbidities.
• Older males with comorbidities face higher mortality, while younger females with diabetes show better recovery potential.