Wald, R. et al. Chronic dialysis and death among survivors of acute kidney injury requiring dialysis. JAMA 302, 1179–1185 (2009).

Future studies will explore factors that predict long-term outcomes...

Acute kidney injury (AKI) requiring in-hospital dialysis is associated with an increased risk of chronic dialysis but does not increase the long-term risk of all-cause mortality, according to a study published in the Journal of the American Medical Association.

“Although there is a great deal of information on the short-term outcomes of patients with AKI, there is a relative dearth of information on what happens to these patients in the long term,” states the study's corresponding author Ron Wald. “In order to understand the relative impact of AKI requiring dialysis on long-term outcomes, it is important to compare such individuals with people who were equally sick but did not have AKI.” Wald and colleagues therefore decided to investigate the long-term risk of chronic dialysis and death in hospitalized patients who experienced an episode of AKI and required acute dialysis in hospital.

The researchers used health databases to obtain data for adults aged ≥19 years in Ontario, Canada, who experienced AKI and required in-hospital dialysis but survived free of dialysis for ≥30 days after discharge between July 1996 and December 2006. Patients were matched with individuals who didn't experience AKI or require dialysis during their index hospitalization, for variables including age, sex, history of chronic kidney disease and a propensity score for AKI development.

In total, 3,769 adults with AKI requiring in-hospital dialysis and 13,598 matched controls were included. After a median follow-up of 3 years, the researchers found that patients who had experienced AKI and required in-hospital dialysis were significantly more likely to require chronic dialysis than matched controls who did not experience AKI or require dialysis (adjusted hazard ratio 3.23; 95% CI 2.70–3.86). The adjusted risk of all-cause mortality was not, however, significantly different between the two groups.

“Future studies will explore factors that predict long-term outcomes among AKI survivors,” states Wald. “In addition, since AKI survivors are at higher risk of progressing to end-stage renal disease, it will be important to test strategies that lead to preservation of kidney function following an episode of AKI.”