**3. Results**

The total sample consisted of 760,664 hospitalizations due to AKI, 52.2% were men, with a mean age of 80.5 ± 7.8 years, and 9% underwent dialysis treatment. Of these patients, 24.3% were admitted during WE and 27.7% died during hospitalization (Table 2).

**Table 2.** Demographic features of the considered sample (AKI: acute kidney injury, WE: weekend effect).


IHM was significantly higher in men (51.8% vs. 48.2%, *p* < 0.001). Deceased subjects were more likely to be older (81.9 ± 7.9 vs. 80 ± 7.7 years, *p* < 0.001), to have higher comorbidity score (15.96 ± 6.48 vs. 14.04 ± 6.02, *p* < 0.001), to be treated with dialysis (17.7% vs. 6.8%, *p* < 0.001), and to show higher admission during WE (25.8% vs. 23.7%, *p* < 0.001), compared to survivors (Table 3).



Patients admitted during WE were more likely to be male (51.5% vs. 48.5%, *p* < 0.001), older (mean age 81 ± 7.8 vs. 80.4 ± 7.8 years, *p* < 0.001), and had a higher comorbidity score (14.75 ± 6.2 vs. 14.52 ± 6.22, *p* < 0.001). No difference was found for prevalence of dialysis dependent AKI (Table 4).



NS: non-significant.

At the logistic regression analysis, IHM was independently associated, in decreasing order, with dialysis-dependent AKI, WE admission, and comorbidity score (Table 5). As for the comorbidity score, the risk of death raised of 5.6% for every 1-point increase.


**Table 5.** Logistic regression analysis showing factors independently associated with in-hospital mortality. OR: Odds Ratio; 95%CI: 95% confidence intervals; WE: weekend.
