Table 2 The association of several risk factors with QTc-prolongation in the development cohort (Bazett formula)

Age (in years) median; IQR

58.0; 14.0

54.5; 23.0

1.02

0.99–1.05

  ≤ 25, n (%)

1 (3.7)

4 (5.0)

Ref.

Ref.

 26–50, n (%)

5 (18.5)

28 (35.0)

0.71

0.07–7.79

 51–75, n (%)

17 (63.0)

43 (53.8)

1.58

0.17–15.19

  ≥ 76, n (%)

4 (14.8)

5 (6.3)

3.20

0.25–41.21

Female gender, n (%)

4 (14.8)

42 (52.5)

0.16

0.05–0.50*

Caucasian race, n (%)

26 (96.3)

74 (92.5)

2.11

0.24–18.35

BMI (kg m^2–1) ^a, mean ± SD

25.7 ± 4.3

27.3 ± 5.3

0.93

0.85–1.03

 Medical Units

14 (51.9)

69 (86.3)

Ref.

Ref.

 Surgical Units

9 (33.3)

8 (10.0)

5.55

1.82–16.86*

 Cardiac Units

4 (14.8)

3 (3.8)

6.57

1.32–32.66*

 Myocardial infarction

1 (3.7)

1 (1.3)

3.04

0.18–50.32

 Heart failure

1 (3.7)

3 (3.8)

0.99

0.10–9.91

 Arrhythmia

6 (22.2)

6 (7.5)

3.52

1.03–12.07*

 Hypertension

12 (48.1)

17 (21.3)

3.44

1.36–8.68*

 Diabetes Mellitus

5 (18.5)

8 (10.0)

2.05

0.61–6.89

 COPD/Asthma

1 (3.7)

11 (13.8)

0.24

0.03–1.96

 Hematological malignancies

12 (44.4)

55 (68.8)

0.36

0.15–0.89*

 Increased ASAT (>  170 / 150 U L^− 1)

–

3 (3.8)

–

–

 Increased ALAT (>  220 / 160 U L^− 1)

–

1 (1.3)

–

–

 Increased bilirubin (>  16 μmol L^− 1)

2 (7.4)

16 (20.0)

0.33

0.07–1.55

eGFR ≤50 ml min^− 1 (MDRD) ^c, n (%)

3 (11.1)

6 (7.5)

1.50

0.35–6.47

Electrolyte disturbances ^d, n (%)

 Hyponatremia (<  136 mmol L^− 1)

2 (7.4)

19 (23.8)

0.25

0.06–1.17

 Hypokalemia (<  3.5 mmol L^− 1)

2 (7.4)

3 (3.8)

2.03

0.32–12.83

 Hypocalcemia (<  2.2 mmol L^− 1)

7 (25.9)

17 (21.3)

1.29

0.39–4.22

 Hypomagnesemia (<  0.7 mmol L^− 1)

4 (14.8)

10 (12.5)

1.33

0.34–5.29

Concomitant medication, median; IQR

8.0; 4.0

8.0; 4.0

1.02

0.86–1.20

Loop diuretics, n (%)

8 (29.6)

15 (18.8)

1.83

0.67–4.95

 0

4 (14.8)

11 (13.8)

Ref.

Ref.

 1

6 (22.2)

28 (35.0)

0.59

0.14–2.50

  ≥ 2

17 (63.0)

41 (51.3)

1.14

0.32–4.09