Characteristic

n

Characteristic

n

Province

Shanghai

Beijing

Hubei

Sichuan

Heilongjiang

Gender

Male

Female

Ages

30 - 39 years

40 - 49 years

≥50 years

4

2

8

3

1

1

17

5

9

4

Education level

Master degree

Doctor degree

Title

Middle professional title

High professional title

Work place

In hospitals

In universities

14

4

4

14

2

16