Covariates recorded by the current study
| Variables | Answers |
| Age | 1=18–44 years, 2=45–60 years, 3=>60 years |
| Gender | 1=male, 2=female |
| Education level | 1=primary school and below, 2=middle school, 3=high school or equivalent, 4=3 year college and above |
| Occupation | 1=employed, 2=unemployed |
| Year of hypertension since being diagnosed | Years |
| Family history of hypertension | 1=yes, 2=no, 3=unknown |
| Registration | 1=locals, 2=migrants |