Acute renal failure (AKI) is defined by a deterioration of kidney function over a short period. This definition was clarified recently in order to allow homogenization and optimal comparison of patients in clinical studies by the classifications RIFLE in 2004, AKIN in 2007 and KDIGO in 2013. These classifications decline several stages of ARI through the increase in the plasma creatinine level and the decrease in urine flow.

Even though AKI is a frequent pathology in all hospitalized patients, there are only few studies that are interested in this entity in conventional hospital services except intensive care or intensive care. Indeed, the recent meta-analysis including the 154 studies focusing on the ARI defined by the KDIGO criteria, only 7 have recruited patients in conventional nephrology services. However, patients admitted for an ARI which requires treatment in a medical service probably have epidemiological characteristics and a different prognosis than those requiring treatment in intensive care. In addition, the parameters of the RIFLE, AKIN or KDIGO scores are more difficult to establish in conventional hospital services than in intensive care, especially for hourly monitoring of urine flow, not allowing an optimal classification of the episode of IRA.

This study set out to develop a prognostic score for intra-hospital mortality in ARI based on a first historical cohort. The investigators then validated this score on a second prospective cohort obtained over an independent inclusion period and at a distance from the first.

Inclusion Criteria:

• all patients over 18 years of age admitted for ARI, defined by an increase in serum creatinine of more than 50% of baseline serum creatinine in patients without chronic kidney disease or an increase in serum creatinine greater than 100 umol / L compared to baseline serum creatinine if the patient had a serum creatinine clearance less than 60 mL / min / 1.73m2 calculated by the MDRD formula (Modification of the Diet in Renal Disease), hospitalized in the Nephrology department of the Besançon University Hospital Center

Exclusion Criteria:

• kidney transplant and patients from an intensive care unit

We included all patients over 18 years of age admitted for ARI, defined by an increase in serum creatinine of more than 50% of baseline serum creatinine in patients without chronic kidney disease or increased serum creatinine at 100 umol / L compared to baseline serum creatinine if the patient had a serum creatinine clearance less than 60 mL / min / 1.73m2 calculated by the MDRD (Modification of the Diet in Renal Disease) formula, hospitalized in the Nephrology department of the Besançon University Hospital Center. Our exclusion criteria were kidney transplantation and patients from the intensive care unit.

In our analysis, we constituted two cohorts: the first from January 1, 2001 to December 31, 2004 for the development of the prognostic score, then a second extending from January 1 2010 to December 31, 2013 for the validation of the score.