Table 4 Charlson comorbidities at baseline (case–control study)

Charlson comorbidities

Cases

Controls

P-value^a

N

%

N

%

N

552

2208

Myocardial infarction

5

0.9%

5

0.2%

0.026

Congestive heart failure

7

1.3%

8

0.4%

0.014

Peripheral vascular disease

4

0.7%

9

0.4%

0.338

Cerebrovascular disease

7

1.3%

10

0.5%

0.037

Dementia

2

0.4%

12

0.5%

0.582

Pulmonary disease

36

6.5%

78

3.5%

0.001

Connective tissue disorder

3

0.5%

6

0.3%

0.327

Peptic ulcer disease

0

0.0%

0

0.0%

NA

Mild liver disease

3

0.5%

2

0.1%

0.05

Diabetes without complications

20

3.6%

26

1.2%

< 0.001

Diabetes with complications

0

0.0%

3

0.1%

0.992

Paraplegia

2

0.4%

2

0.1%

0.166

Renal disease

11

2.0%

13

0.6%

0.002

Cancer

12

2.2%

20

0.9%

0.01

Moderate or severe liver disease

2

0.4%

0

0.0%

0.992

Metastatic cancer

1

0.2%

7

0.3%

0.589

AIDS/HIV

0

0.0%

0

0.0%

NA

Charlson comorbidity index

Cases

Controls

P-value

N

%

N

%

N

Total

552

2208

< 0.001^b

CCI score

Average

0.27

0.12

Standard deviation

0.88

0.63

CCI category

0

481

87.1%

2057

93.2%

< 0.001^c

1–2

50

9.1%

126

5.7%

3–4

17

3.1%

15

0.7%

≥5

4

0.7%

10

0.5%