Table 2.

Risk of In-Hospital Mortality According to Patient and Stay Characteristics

Characteristic	OR (95%CI)	P Value
Serum sodium concentration, mmol/L
< 125	7.95 (5.91–10.53)	<.001
[125;130)	5.59 (4.62–6.72)	<.001
[130;135)	3.58	<.001
[135;145]	1 [Reference]
(145;150]	9.19 (7.06–11.83)	<.001
(150;155]	10.16 (5.10–18.74)	<.001
Age, years
< 30	1 [Reference]	NA
[30;40)	0.66 (0.45–0.97)	.0381
[40;50)	1.02 (0.74–1.40)	.9256
[50;60)	1.94 (1.49–2.56)	<.001
[60;70)	1.83 (1.42–2.41)	<.001
[70;80)	2.43 (1.88–3.18)	<.001
[80;90)	4.00 (3.11–5.24)	<.001
≥ 90	6.41 (4.80–8.66)	<.001
Sex
F	1 [Reference]	NA
M	1.20 (1.09–1.32)	<.001
Duration of hospital stay, days
≤ 7	1 [Reference]	NA
(7;14]	1.59 (1.41–1.80)	<.001
(14;21]	2.55 (2.19–2.97)	<.001
(21;42]	4.04 (3.50–4.66)	<.001
> 42	5.81 (4.80–6.98)	<.001
Number of ICD-10 codes
≤ 1	1 [Reference]	NA
(1;4]	1.39 (1.08–1.80)	.0112
(4;7]	3.96 (3.13–5.08)	<.001
(7;10]	7.34 (5.78–9.44)	<.001
(10;15]	10.61 (8.32–13.69)	<.001
(15;20]	18.31 (13.84–24.40)	<.001
> 20	31.77 (23.50–43.20)	<.001
Hospital admissions via the emergency department	2.29 (2.04–2.56)	<.001
Any surgery	1.04 (0.94–1.15)	.402
ICU stay	11.85 (10.29–12.69)	<.001
Palliative care	12.75 (10.54–15.38)	<.001
Dialysis	15.49 (13.86–17.30)	<.001
Dementia	2.67 (2.11–3.34)	<.001
Charlson Comorbidity Index
0	1 [Reference]	NA
1	2.72 (2.21–3.36)	<.001
2	4.56 (3.76–5.54)	<.001
3–4	7.59 (6.31–9.17)	<.001
5–9	12.12 (10.11–14.62)	<.001
≥ 10	19.86 (15.31–25.72)	<.001

Abbreviations: OR Odds ratio, CI Confidence interval, ICU Intensive care unit, ICD International Statistical Classification of Diseases and Related Health Problems