Lafrance and Miller looked at VA data involving 864,933 U.S. veterans (4.9% female) who survived at least 90 days after a hospital discharge. Of those, 82,711 had acute kidney injury that did not require dialysis.
Through a mean follow-up of 2.34 years, the rate of death was higher in patients with acute kidney injury — 29.8% versus 16.1%.
After adjustment for demographics, comorbidities, medication use, primary diagnosis of admission, length of stay, mechanical ventilation, and postdischarge kidney function (estimated glomerular filtration rate), patients with acute kidney injury were 41% more likely to die during follow-up (HR 1.41, 95% CI 1.39 to 1.43).
The mortality risk increased significantly with greater severity of acute kidney injury (P<0.001 for trend), reaching a hazard ratio of 1.59 (95% CI 1.54 to 1.65) for those with stage III injury.
The risk of dying during follow-up was reduced, but still elevated, in patients with lower baseline kidney function, older patients, and those with diabetes.
Even among patients whose kidney function declined by 10% or less from the baseline assessment — who were considered to have recovered or to have maintained function — acute kidney injury was still associated with significantly higher mortality (HR 1.47, 95% CI 1.43 to 1.51).
