Table 1 Demographic characteristics

Total number, n (%)

6238

7501

Gender, female, n (%)

3319 (53.2%)

5077 (67.7%)

Age, mean (SD), years

67.6 (10.6)

69.7 (9.5)

Bilateral operation, n (%)

418 (6.7%)

1225 (16.3%)

BMI^a, mean (SD), years

28.2 (4.7)

29.9 (4.8)

Diabetes

473 (7.6%)

744 (9.9%)

Neurodegenerative disease^b

86 (1.4%)

111 (1.5%)

Cardiac disease^c

699 (11.2%)

904 (12.1%)

Pulmonary disease

373 (6.0%)

619 (8.3%)

Hypertension

1656 (26.5%)

2491 (33.2%)

Epilepsy

67 (1.1%)

74 (1.0%)

History of malignancy

182 (2.9%)

273 (3.6%)

 1

637 (10.2%)

373 (5.0%)

 2

2398 (38.4%)

2910 (38.8%)

 3

1766 (28.3%)

2590 (34.5%)

 4

90 (1.4%)

97 (1.3%)

 missing

1347 (21.6%)

1531 (20.4%)