Table 3.

Data distribution comparison for categorical and numerical variables

	MIMIC-III vs. MIMIC-IV	MIMIC-III vs. eICU-CRD	MIMIC-IV vs. eICU-CRD
2 categorical variables	$\mathit{p}$ values of Pearson’s chi-squared test & effect sizes of Cramér’s $\mathit{V}$ value
AKI label	***, +	***, +	***, +
Gender	***, +	***, +	***, +
17 numerical variables	$\mathit{p}$ values of Welch’s $\mathit{t}$-test & effect sizes of absolute Cohen’s $\mathit{d}$ value
Age	⁑, +	***, +	***, +
Potassium	***, +	***, +	***, +  +
Mean corpuscular volume (MCV)	***, +  +	***, +	***, +
Sodium	⁑, +	*, +	⁑, +
Total calcium	***, +	***, +	***, +
Phosphate	***, +	***, +	***, +
Magnesium	***, +	***, +	***, +  +
International normalized ratio (INR)	*, +	***, +	***, +
Red blood cell distribution width (RDW)	***, +	***, +	***, +
Anion gap	***, +	***, +  +  +  +	***, +  +  +  +
Prothrombin time (PT)	***, +	***, +	***, +
Blood pH	***, +  +  +	***, +	***, +  +  +  +
Blood urea nitrogen (BUN)	***, +	***, +	***, +
Lactate	***, +	⁑, +	***, +
Creatinine	***, +	***, +	***, +
Total bilirubin	***, +	***, +	***, +
Partial thromboplastin time (PTT)	***, +	***, +	***, +

⁑$p\ge 0.05$, *$p<0.05$, **$p<0.01$, ***$p<0.001$, + $0<V\le 0.2$, +  + $0.2<V\le 0.5$, +  +  + $0.5<V\le 0.8$, +  +  +  + $0.8<V$, + $0<|d|\le 0.2$,  +  + $0.2<|d|\le 0.5$, +  +  + $0.5<|d|\le 0.8$, +  +  +  + $0.8<|d$