Table 1.

Characteristics of subjects.

Age (y)	Number (total 607)
18–29	179
30–44	305
45–59	112
>60	11
Gender
Male	269
Female	338
Profession
Physician	133
Nurse	162
Laboratory staff	233
Others	79
Institution
Private hospital	119
Government hospital	452
Poly clinic (private sector)	36
Nationality
Saudi	446
Non-Saudi	161