Table 3 Odds Ratio of in-hospital mortality in selected subgroups of patients with and without hyponatremia

 Male

1 (ref)

4.0 (3.5–4.6)

10.9 (9.2–12.8)

23.6 (18.9–29.5)

26.3 (18.7–37.0)

 Female

1 (ref)

6.0 (5.0–7.1)

20.2 (16.8–24.4)

37.1 (28.6–48.1)

42.4 (28.9–62.0)

 18–29

1 (ref)

6.2 (3.6–10.5)

28.5 (16.6–49.1)

44.3 (18.4–106.7)

69.9 (23.0–212.2)

 30–39

1 (ref)

9.0 (5.4–15.0)

41.4 (24.3–70.6)

46.7 (20.3–107.4)

25.7 (5.6–118.0)

 40–49

1 (ref)

6.4 (4.4–9.2)

30.6 (20.8–45.0)

63.8 (38.1–106.7)

60.6 (25.5–144.3)

 50–59

1 (ref)

7.8 (6.0–10.3)

22.6 (16.4–31.0)

51.9 (34.7–77.7)

60.7 (31.8–115.6)

 60–69

1 (ref)

4.9 (3.7–6.4)

16.9 (12.7–22.4)

29.2 (19.5–43.5)

38.8 (22.5–67.0)

 70–79

1 (ref)

3.3 (2.7–4.1)

8.4 (6.7–14.1)

23.0 (16.9–31.2)

24.6 (15.4–39.1)

  ≥ 80

1 (ref)

2.2 (1.7–2.9)

4.3 (3.2–5.8)

6.7 (4.4–10.3)

7.2 (3.0–13.2)

 Infectious disease

1 (ref)

2.8 (1.6–5.0)

5.0 (2.7–9.4)

7.6 (3.2–18.2)

15.4 (4.9–48.9)

 Cancer

1 (ref)

6.4 (5.3–7.7)

23.8 (19.5–29.1)

58.9 (45.1–77.0)

55.7 (36.4–85.3)

 Cardiovascular disease

1 (ref)

2.3 (1.8–3.0)

6.2 (4.6–8.4)

13.2 (8.3–21.1)

14.6 (6.7–31.8)

 Gastrointestinal disease

1 (ref)

5.2 (3.2–8.2)

11.2 (6.5–19.3)

19.5 (9.2–41.3)

45.0 (16.9–119.5)

 Observation for suspected disease

1 (ref)

4.6 (2.6–8.2)

12.7 (7.0–23.0)

10.6 (3.8–29.8)

45.9 (16.5–127.9)

 Muscle and connective tissue disease

1 (ref)

6.0 (4.0–9.0)

27.8 (17.8–43.4)

29.6 (15.0–58.4)

52.1 (21.4–126.6)

 Respiratory disease

1 (ref)

4.0 (2.9–5.5)

6.3 (4.4–8.9)

7.2 (4.3–12.1)

12.2 (6.3–23.6)

 Others

1 (ref)

3.9 (2.4–6.3)

12.2 (7.1–21.1)

29.0 (15.3–55.0)

21.9 (7.7–62.3)

 Neurologic disease

1 (ref)

5.4 (1.9–15.3)

2.0 (0.2–16.4)

21.4 (5.0–91.6)

 Endocrine disease

1 (ref)

7.1 (2.0–25.6)

25.8 (6.9–96.4)

17.5 (2.0–151.9)

 Urogenital disease

1 (ref)

8.9 (3.9–20.5)

35.3 (14.4–87.1)

166.2 (66.7–413.8)

45.7 (8.9–235.8)