The Largest Meta-analysis on Global AKI Incidence

This month, the Clinical Journal of the American Society of Nephrology (CJASN) published a meta-analysis on the epidemiology and global incidence of acute kidney injury (AKI) last month. 

Dr. Bertrand L. Jaber and his colleagues from Tufts University School of Medicine included 312 published cohort studies (between 2004 and 2012) with 49 million adult and pediatric patients, from over 40 countries across all continents.

Incidence of AKI:

• The pooled incidence rate of AKI was 10.7% using all the 312 studies. However, in a subgroup analysis of 154 studies that used a KDIGO-equivalent AKI definition, the pooled incidence rate of AKI was 23.2%.
• The highest pooled incidence rate of AKI was found in ICU to be 37%, followed by cardiac surgery 24%.
• The pooled incidence rate of AKI was higher in countries south versus north of the Equator (27% vs 22%, respectively), and higher in countries that spent more than 10% of its GDP on total health expenditure vs those countries that spend less than 5% (25% vs 14%).

Incidence of AKI-associated mortality:

• The pooled incidence rate of AKI-associated mortality was 23%.

Ancillary findings:

• There were 269 studies of adults, 42 studies of children, and 1 study combining adults and children.
• There were 62% retrospective cohort studies, 35% prospective cohort studies, and 3% post hoc cohorts derived from clinical trials.
• Sample size of individual studies on adults ranged from 500 to 12 millions, and on children varied from 64 to 60 thousands.
• The mean age ranged from 23 to 80 years for adults and from 0 to 13 years for children.
• Studies from high-income countries represented 87% of the studies included in this meta-analysis

Comment:

This is a landmark meta-analysis in the area of AKI epidemiology. It is the first and largest meta-analysis of AKI incidence that include both adults and pediatric patients from allover the world. Beside the surprising findings that AKI occurs around the world, there has been a disparity in the representation of certain countries in this meta-analysis, simply due to the lack of published evidence from these countries. The findings of high AKI incidence in high-income countries warrant further investigations to identify the causes and develop solutions. However, I believe that the low incidence from countries that spend less than 5% of their GDP on health expenditure could be false. This could be attributed to the underdiagnosis of AKI from lacking nephrology-trained physicians. Besides, lack of scientific publications in this area could contribute to the potentially false low incidence, in my opinion.

Jaber et al conclude:

“…discussions should encourage providers to design better hospital-based health care delivery systems that focus on the prevention, early detection, and treatment of AKI, improve patient safety, and ultimately, preserve kidney health and well-being while mitigating the long-term costly burden of CKD."